Below in this subsection, a fairly simple scheme for diagnosing the most common failures is given. The causes of violations and their symptoms are grouped according to their relationship to the functioning of a particular unit or system: «Engine», «Cooling system» etc.
Regardless of the nature of the failure, the investigation of its cause is always based on the same basic principles:
- Make sure you identify the symptoms of rejection correctly. The foregoing means confidence in determining the boundaries of the search area, which is especially important when diagnosing a failure to another motorist who cannot adequately state the symptoms of an existing violation.
- Try not to overlook obvious violations. For example, if the engine won't start, feel free to check for fuel in the gas tank (at the same time, the statements of the owner of the faulty car should not be taken for granted). In the event of a failure of electrical equipment, first of all, you should check the condition and reliability of fastening of the terminal connections of the electrical wiring, only after that it makes sense to get diagnostic tools.
- Try to address the cause of the failure, not its symptom. Replacing a dead battery with a new one will help start the engine, but the existing cause of the discharge of the old battery will remain uncorrected, which will lead to a quick failure of the new one. Similarly, replacing oil-stained spark plugs will allow the engine to function properly for a while, but the failure will certainly repeat itself soon (if the reason lay not simply in the use of candles of the wrong type).
- Don't take any claims for granted! Please note that the newly installed «new» a component may also be defective, especially if it has been in the trunk for a long time - you should not exclude a component from the list of checks just because it is new or recently installed. In case of neglecting the implementation of this recommendation, one should not be surprised when the reason for the failure, finally revealed, turns out to be lying on the surface from the very beginning.
Diagnostics of failures and reasons for the decrease in engine efficiency
Engine won't crank when trying to start it
- Faulty ignition switch.
- The pole terminals of the battery are oxidized, or the fastening of the wire lugs on them is loosened.
- The battery is discharged or defective.
- The correct functioning of the charge system is broken.
- The electrical wiring of the starting system circuit is broken or otherwise damaged, or the fastening of the terminals of the contact connections is loose.
- The traction relay or starter switch has failed.
- Starter motor defective.
- Broken or worn starter drive gear teeth or flywheel ring gear.
- The starter drive gear is wedged in the flywheel ring gear.
- Faulty start enable switch (models with AT) or starter open circuit switch (models with manual transmission)
- AT is not translated into position «R» or «N».
- Engine stuck (the crankshaft or camshaft is stuck, or one of the pistons has stuck on the wall of its cylinder), - try to turn it by hand on the crankshaft pulley bolt.
Engine cranks but won't start
- Empty fuel tank.
- Low battery (engine cranks too slowly).
- The pole terminals of the battery are oxidized, or the fastening of the wire lugs on them is loosened.
- Starter defective.
- The patency of the fuel lines is broken, the fuel pump is faulty, or the ventilation pipes of the fuel tank are blocked.
- The cylinder head cover bolts are loose or the gasket is damaged.
- The valves are burnt out, or the density of pressing them to the seats is broken.
- Damaged (s) valve stem (ov).
- Worn or broken valve spring (s).
- Valve clearances out of adjustment.
- Worn or burnt piston rings.
- The compression pressure has fallen or is unevenly distributed between the engine cylinders.
- Moisture has entered the fuel.
- Unsuitable oil is used (low viscosity)
- Faulty fuel injector (s).
- Moistened or damaged components of the ignition system.
- The ignition system malfunctioned.
- Spark plugs are worn or damaged, or the electrode gap setting is broken.
- The setting of the ignition timing is violated.
- The wiring of the ignition circuit is broken or otherwise damaged, the fastening of the terminals of the contact connections is loose, or the ignition coil is faulty.
- As a result of wear of the timing drive components, the valve timing settings are violated.
- The timing belt/chain is broken or its tension is loose.
Difficulty starting a cold engine
- Low battery.
- The pole terminals of the battery are oxidized, or the fastening of the wire lugs on them is loosened.
- Spark plugs are worn or damaged, or the electrode gap setting is broken.
- Faulty fuel supply system.
- There are fuel leaks through the injector (s).
- The compression pressure has dropped.
Difficulty starting a hot engine
- The air cleaner filter element is dirty, or its patency is otherwise impaired.
- Faulty fuel supply system (fuel is not getting to the injectors).
- Battery terminal connections oxidized (especially mass).
- The quality of the grounding of the power unit is violated.
- Serviceability of functioning of system of giving of fuel or management of the engine is broken.
- Serviceability of functioning of system of catching of fuel evaporations is broken (EVAP).
- The compression pressure has dropped.
Entering the starter into gear is difficult, or accompanied by extraneous noise
- Broken or worn starter drive gear teeth or flywheel ring gear.
- Loose or loose starter mounting bolts.
- Worn or damaged internal starter components.
Engine starts but immediately stalls
- Broken or otherwise damaged ignition circuit wiring, or loose terminals of the contact connections on the ignition module or generator.
- There is a fuel starvation of the injector (ov).
- The air cleaner element is dirty.
- There are vacuum losses.
- The idle speed setting is violated.
- There are intake air leaks or the vacuum lines are damaged.
- Valve clearances out of adjustment.
- Unsuitable oil is used (low viscosity).
- The compression pressure has fallen or is unevenly distributed between the engine cylinders.
- The setting of the ignition timing is violated.
- The valve timing settings are broken as a result of wear of the timing drive components.
During parking, oil leaks under the engine
- There are leaks from the oil pan gasket or drain plug.
- There are leaks through the seat seal of the oil pressure switch.
- There are leaks from the cylinder head gasket.
- There are leaks through the engine shaft seals.
- There are leaks in the oil pump.
Idle speed stability is broken
- There are vacuum losses.
- Faulty exhaust gas recirculation valve (EGR).
- Violated patency of the valve of the crankcase ventilation system (PCV).
- Air cleaner element blocked.
- The fuel pump does not provide the required fuel consumption.
- Cylinder head gasket leaking.
- Timing drive components worn out.
- Camshaft lobes worn out (ov).
- Valve clearances out of adjustment.
- The valves are burned out, or the valves are not tightly pressed against their saddles.
- The setting of the ignition timing is violated.
- The ignition system malfunctioned.
- The thermostatic air cleaner is malfunctioning.
- Spark plugs are worn or damaged, or the electrode gap setting is broken.
- The compression pressure has fallen or is unevenly distributed between the cylinders.
- Damaged fuel injectors (ov).
- The idle speed setting is violated.
There are misfires at idle
- Spark plugs are worn or damaged, or the electrode gap setting is broken.
- Faulty spark plug wires.
- Moistened or damaged components of the ignition system.
- There is a short in the ignition circuit.
- The quality of the contact connections of the explosive wires is broken, or the ignition module is faulty.
- Faulty ignition coil.
- The components of the toxicity reduction system are faulty, or the patency of the corresponding tract is impaired.
- There are leaks in the EGR valve.
- The patency of the fuel filter is broken, or the fuel is contaminated.
- There are vacuum losses.
- RPM or idle mixture quality settings are violated.
- The setting of the ignition timing is violated.
- The compression pressure has fallen or is unevenly distributed between the cylinders.
- There is a loss of vacuum in the intake manifold or through the connecting vacuum hoses.
- The patency of the fuel injectors is broken.
Misfire occurs while driving in gear
- The patency of the fuel filter / connecting path of the power system is broken.
- The fuel pressure has dropped.
- Spark plugs are worn or damaged, or the electrode gap setting is broken.
- The setting of the ignition timing is violated.
- The reliability of the fastening of the contact connections of the explosive wires is broken, or the ignition module is faulty.
- Occurs «breakdown» wiring BB spark plug wires.
- Components of systems of decrease in toxicity of the fulfilled gases are faulty.
- The compression pressure has fallen or is unevenly distributed between the cylinders.
- The ignition system is faulty, or the contact connections of its electrical wiring are loose.
- There are vacuum losses.
- The fuel pump is faulty, or the pressure it develops has dropped.
- The ventilation of the fuel tank is broken.
Excessively high idle speed
- The smoothness of the throttle actuator is broken.
- The idle speed setting is violated.
- There are leaks in the intake air path.
- The correct functioning of the engine management system is broken.
Battery not «keeps» charge
- The alternator drive belt is worn out, or the adjustment of its tension force is broken.
- The pole terminals are oxidized, or the fastening of the wire lugs on them is loosened.
- The level of electrolyte in the banks has dropped.
- The generator does not produce the required charge current.
- The electrical wiring of the charge system circuit is broken or otherwise damaged, or the fastening of the terminals of the contact connections is loose.
- The battery is being discharged due to a short circuit in the onboard wiring.
- There is an internal defect in the battery.
The charge indicator lamp stays on while the engine is running
- There is an internal defect in the generator or voltage regulator.
- The alternator drive belt is worn or broken, or the adjustment of its tension force is broken.
- Worn, jammed or dirty alternator brushes.
- Weak or broken alternator brush springs.
- The charge circuit wiring is broken, or the terminal connections are loose.
The charge control lamp does not light up when the key is turned to the ON position
- The filament burned out.
- The printed circuit board of the instrument cluster is faulty, or the lamp holder is faulty.
- Generator defective.
The stability of the engine speed is violated during acceleration
- The ignition system malfunctioned.
- The setting of the ignition timing is violated.
- Spark plugs are worn or damaged, or the electrode gap setting is broken.
- The patency of the fuel filter is broken.
- The patency of the fuel injectors is broken.
- The fuel pressure has dropped as a result of a malfunction in the functioning of the fuel pump or the patency of the fuel lines.
- The serviceability of the functioning of the injectors, or the engine management system is broken.
- Loose connector fastening (ov) fuel injector wiring.
- There are air leaks in the intake tract.
- The EGR system malfunctioned.
The engine runs jerky when the accelerator pedal is held motionless
- There are air leaks in the intake tract.
- Faulty fuel pump or fuel pressure regulator.
- Loose connector fastening (ov) fuel injector wiring.
- There are malfunctions of the engine management system.
The engine spontaneously stalls
- The idle speed setting is violated.
- The patency of the fuel filter is broken, or moisture has got into the power system.
- Moistened or damaged components of the ignition system.
- Components of systems of decrease in toxicity of the fulfilled gases are faulty.
- Spark plugs are worn or damaged, or the electrode gap setting is broken.
- Faulty spark plug wires.
- There are vacuum losses at the throttle body, intake manifold or through the connecting hoses.
- Valve clearances out of alignment.
- The fuel pump is faulty, or the pressure it develops has dropped.
- The ventilation of the fuel tank is broken, or the fuel lines are blocked.
- Serviceability of functioning of system of injection or management of the engine is broken.
Decreased engine power
- Damaged crankcase ventilation hose.
- Damaged vacuum hose.
- Damaged intake manifold gasket.
- The setting of the ignition timing is violated.
- Damaged spark plug wires or ignition coil.
- Spark plugs are worn or damaged, or the electrode gap setting is broken.
- The correct functioning of the fuel supply system is broken.
- Air cleaner element blocked.
- The brakes are jammed.
- The level of ATF in AT has fallen.
- Oil pressure dropped.
- Clutch slips (RKPP).
- The patency of the fuel filter is broken, or moisture has got into the power system.
- The EGR system malfunctioned.
- The car is filled with non-standard fuel.
- Compression pressure dropped or unevenly distributed between the cylinders
- Disturbed patency of the exhaust tract.
- The fuel pump is faulty, or the pressure it develops has dropped.
- There are leaks in the intake air path.
- Serviceability of functioning of system of injection or management of the engine is broken.
- The engine is overheated.
- The engine has not warmed up to normal operating temperature.
Happening «shots» in the exhaust tract
- The EGR system malfunctioned.
- The setting of the ignition timing is violated.
- The air cleaner thermostat is malfunctioning.
- There are vacuum losses.
- Valve clearances out of alignment.
- Damaged valve springs or «sticking» valves.
- There are leaks in the intake air path.
- There is a malfunction in the secondary (BB) ignition circuit (candle insulators, BB wires, ignition module).
- The correct functioning of the fuel supply system is broken.
The engine runs jerky when the accelerator pedal is held motionless
- There are air leaks in the intake tract.
- Fuel pump defective.
- Loose connector fastening (ov) fuel injector wiring.
- There are malfunctions of the engine management system.
During acceleration or when the load on the engine is increased, there are knocks caused by too early ignition or detonation
- The vehicle was filled with the wrong grade of fuel.
- The setting of the ignition timing is violated.
- There is excessive carbon formation in the combustion chambers.
- Custom spark plugs installed.
- The correct functioning of the fuel supply system is broken.
- Damaged BB wires.
- The EGR valve is malfunctioning.
- There are vacuum losses.
- Faulty knock sensor.
- Valve clearances out of adjustment.
- Worn or damaged valve springs.
- There is a mechanical failure of the valve drive components (rocker arms, rocker axles, etc.).
The engine continues to run after the ignition is turned off (diesel effect)
- There are leaks in the injectors.
- Excessively high idle speed is set.
- Engine operating temperature is too high.
- The setting of the ignition timing is violated.
- There is excessive carbon formation on the bottoms of the pistons.
- going on «sticking» valves.
- Valve clearances set incorrectly.
- The EGR system malfunctioned.
There is a drop in engine oil pressure
- The oil level has dropped, or the wrong grade of oil has been filled.
- Worn engine bearings and/or oil pump.
- The engine is overheating.
- Oil filter blocked.
- The patency of the mesh filter of the oil intake is broken.
- Excessively low idle speed is set.
- There was a short circuit in the braid of the onboard electrical wiring.
- Defective oil pressure gauge.
Excessive consumption of engine oil
- Loose oil pan drain plug.
- Damaged crankcase ventilation hose.
- Faulty crankcase ventilation valve.
- The pan mounting bolts are loose, or its sealing gasket is damaged.
- The front cover mounting bolts are loose or the sealing gasket is damaged.
- Damaged crankshaft seal.
- The cylinder head cover bolts are loose or the gasket is damaged.
- Loose oil filter seat.
- The tightening force of the oil pressure switch has loosened.
- There is excessive wear on the pistons or cylinders.
- Worn or damaged piston rings.
- Worn or damaged valve stem seals for intake and/or exhaust valves.
- Worn valve stems.
- Worn or damaged valve guides.
Various kinds of noises that occur during engine operation
- A loud thud, more likely to occur during acceleration, indicates worn or damaged main bearings, or uneven crankshaft wear.
- Similar to the above, but slightly higher frequency, the sound that also occurs more often during acceleration indicates a possible wear of the connecting rod bearings.
- An overlapping metallic knock that increases with increasing engine speed and weakens as the latter warms up indicates excessive wear on the pistons and cylinder walls.
- Frequent clicking, which increases with acceleration, indicates wear on the piston pins or nests for their fit in the pistons (sound occurs each time the corresponding piston passes TDC).
- A metallic clicking sound from the water pump indicates worn bearings and the need to replace the pump assembly.
- The cause of frequent knocking or clicking, increasing with increasing speed, may be a violation of the adjustment of valve clearances - listen to the valve mechanism with a stethoscope / piece of vacuum hose. If adjusting the valves does not correct the situation, the condition of the hydraulic tappets and other components of the valve mechanism should be checked.
In some cases, the elimination of knocking is helped by filling the engine with oil with a higher viscosity coefficient.
- The cause of a uniform metallic knock or rumble emitted by the timing drive on 3.0 L models may be wear on the gas distribution chain or a violation of its tension adjustment; also check the condition of the sprockets.
Diagnostics of malfunctions of the lubrication system
Engine oil pressure warning light does not turn off
- Damaged oil pressure sensor (Diaphragm damaged, oil leaking, spring broken or contacts stuck).
- The oil pressure dropped as a result of a blockage in the full-flow oil filter.
- The oil pressure dropped as a result of a violation of the patency of the oil pump pressure reducing valve.
- Violated patency of oil flows.
- The patency of the mesh filter of the oil intake is broken.
- The engine oil level has dropped.
- Damaged oil pickup.
- Stuck oil pump rotors.
The oil pressure warning light does not come on when the ignition is turned on
- The lamp has burned out.
- The wiring is broken, or the quality of the contact connections is broken.
The control lamp starts to work in the frequent flashing mode
- The quality of the contact connections in the corresponding circuit is broken.
- Oil pressure dropped.
- Electrical wiring damaged.
Diagnostics of malfunctions of systems of supply of fuel and release of the fulfilled gas
There are violations of the fuel supply to the injectors
- There is a fault in the electrical circuit of the fuel pump.
- Dust or moisture has entered the fuel pump.
- Fuel pump clogged with dust or water.
- Air has entered the power system.
- Violated patency of the air or ventilation tract.
- Serviceability of functioning of a regulator of pressure of fuel is broken (e.g. broken diaphragm).
Excessive fuel consumption
- The air cleaner filter element is dirty or otherwise obstructed.
- Valve clearances out of adjustment.
- Worn valve seats.
- Valve stems damaged.
- Worn or damaged valve springs.
- The setting of the ignition timing is violated.
- Spark plugs are worn or damaged, or the electrode gap setting is broken.
- The cylinder head cover bolts are loose or the gasket is damaged.
- Worn or burnt piston rings.
- The installation of the gas distribution phases is violated.
- An engine oil with an excessively low viscosity is used.
- The idle speed setting is violated.
- There are leaks in the fuel line.
- The patency of the fuel injectors is broken.
- Serviceability of functioning of system of injection of fuel or management of the engine is broken.
- Serviceability of functioning of systems of decrease in toxicity is broken.
- Insufficient tire inflation pressure, or wrong wheel size fitted.
- «tacked on» brakes.
- The engine does not warm up to normal operating temperature.
- Throttle cable adjustment is broken.
There are fuel leaks (in the cabin and near the car distinctly smells of gasoline)
- Damaged mechanically or as a result of corrosion development of the fuel tank, fuel lines or their union connections.
- The fuel tank seal has come apart.
- Damaged fuel tank drain system.
- Ventilation lines obstructed.
- The tank is full.
- The patency of the carbon adsorber of the EVAP system is broken.
- There are leaks in the EVAP system path.
- The correct functioning of the fuel supply system is broken.
- Damaged or excessively worn internal fuel injector components.
Fuel gauge gives incorrect readings
- Damaged fuel gauge assembly.
Noise
- Fuel pump damaged.
Excessively noisy or smoking exhaust system
- There are exhaust gas leaks through the joints of the exhaust manifold or sections of the exhaust system.
- Mufflers or pipes of the exhaust system are damaged mechanically or as a result of corrosion.
- As a result of damage to the suspension supports, the exhaust system comes into contact with body or suspension elements during movement.
Diagnosis of malfunctions of the cooling system
The engine gets very hot
- The coolant level has dropped.
- The timing belt is damaged or its tension is not adjusted
- Accessory drive belt dirty with oil.
- The patency of the water or air paths of the radiator is broken.
- There are coolant leaks from the radiator.
- Water pump defective.
- Faulty thermostat.
- Poor quality coolant filled.
- There is a malfunction in the fan circuit (ov) cooling systems.
- There is mechanical damage to the impeller of the cooling fan.
- The tightness of the radiator cap is broken.
- The setting of the ignition timing is violated.
- There is an over-depletion of the air-fuel mixture.
- The clutch is slipping.
- «tacked on» brakes.
- Incorrect distance between piston and cylinder wall.
- The cooling system path is blocked by an air lock.
- Wrong type of gear oil filled.
- Exhaust tract resistance too high (high back pressure).
- Inaccurate temperature readings.
Engine does not warm up to normal operating temperature
- The ambient temperature is too low.
- Faulty thermostat.
- There is a malfunction in the cooling fan circuit.
- Inaccurate temperature readings.
There are external coolant leaks
- The hoses of the cooling path are mechanically damaged or destroyed as a result of aging of the material, or the clamps of their fastening are loosened.
- Worn or damaged water pump seals (coolant will seep through the check hole).
- There are coolant leaks from the radiator or expansion tank.
- Damaged drain or squeeze plugs in the water jacket of the engine block.
- The tightness of the landing of the sensor-switch of the coolant temperature is broken.
- Block/cylinder head gaskets damaged or casting cracked.
- Thermostat cover damaged.
- Radiator cap defective.
- The coolant has boiled as a result of overheating.
There are internal coolant leaks
The presence of internal leaks is confirmed by the presence of coolant in the engine oil, causing the latter to emulsify.
- Broken cylinder head gasket.
- Cracked cylinder head or block.
- Loose cylinder head bolts.
There is a loss of coolant
- Too much coolant has been added to the system.
- The coolant boils away as a result of overheating.
- There are external or internal coolant leaks (see above).
- Radiator cap defective.
- The pressure in the cooling system rises due to compression in the cylinders as a result of cracks in the head or block, or a violation of the integrity of any of the seals.
Coolant circulation interrupted
- The water pump is faulty - check by probing the upper radiator hose.
- The patency of the cooling tract is broken.
- Loose water pump drive belt.
- Stuck thermostat.
- The coolant level has dropped.
Various kinds of noise
- Drive belt defective.
- Faulty cooling fan.
- Defective water pump bearing.
- Damaged water pump seal.
Corrosion develops
- Excessively contaminated coolant - add only distilled rainwater to the system.
- Antifreeze too diluted.
- The coolant is not often replaced and the path is flushed.
Diagnostics of malfunctions of systems of heating, ventilation and air conditioning
Heating and ventilation systems
The functioning of the heater fan is completely broken
- The corresponding fuse has blown.
- There was a break in the wiring.
- There is an open in the control switch/fan resistor assembly circuit.
- Faulty fan drive motor.
The supply of heated air to the passenger compartment is disrupted
- Insufficient fluid level in the engine cooling system.
- Engine does not warm up to normal operating temperature (see above).
- Heat exchanger inlet valve defective. Check the valve cable/vacuum actuator for proper operation. Several times move the temperature selection switch to the extreme positions, checking the correct operation of the valve. Warm up the engine to normal operating temperature and, having selected the maximum temperature of the heater, feel the hoses at the inlet and outlet of the valve assembly. If the hoses are at different temperatures, replace the valve.
When the heater is turned on, the windshield fogs up
- There are leaks of coolant from a hose laid near the bulkhead of the engine compartment or under the dashboard of the car - check the tightness of the mounting clamp.
- There are coolant leaks from the heater heat exchanger. Carefully inspect the floor mats in the driver's and front passenger's footwells for leaks.
The coolant has a characteristic sweet smell. If necessary, make appropriate repairs or replace the failed heat exchanger.
On some models to provide access to the heat exchanger (radiator) heater requires the instrument panel to be removed.
Serviceability of functioning of management of a choice of temperature mode is broken
- The coolant level has dropped.
- The electromotor of a drive of a mode gate is faulty.
Cannot turn off closed ventilation mode
- Selector switch defective.
- There is a malfunction in the corresponding damper drive motor circuit.
Air conditioning system with manual control
In addition to the malfunctions listed in the previous subsection:
Cold air does not flow through the vents
- Heater fan defective (see above).
- Faulty heater fan control switch.
- Violated patency of air ducts.
- The air conditioning system needs to be charged.
Attention! Emptying, charging and checking the refrigeration circuit must be carried out in a specialized workshop!
- The accessory drive belt is broken or its tension is loose.
- The K/V switch is faulty.
- The K/V compressor is faulty.
- Serviceability of functioning of the coupling of coupling of the compressor К/В is broken. Check the condition of the clutch and wiring of its circuit.
- Correct the identified problems, replace the defective components.
- The pressure switch of the low-pressure path of the air conditioning system is faulty.
- There is damage to the wiring of the air conditioning circuit, or the corresponding relay has failed. Check, eliminate the identified problems, if necessary, replace the relay.
When using A / V on the floor in the cabin, moisture streaks are formed
- The patency of the drainage tube of the evaporator of the air conditioning system is broken. Clean the tube where it exits the vehicle.
- The evaporator drain hose is blocked. Clean the hose where it exits the vehicle.
Activation of A/C is accompanied by the smell of mold in the cabin
- The patency of the drain hose of the evaporator of the air conditioning system is broken. Clean the hose where it exits the vehicle.
Automatic air conditioning system (climate control)
The system does not activate when the ignition is turned on
- Blown fuse #5 or #17.
- The quality of the contact connections in the wiring of the corresponding circuit is broken (special attention should be paid to the ground loop).
- Faulty A/C control assembly.
The function of saving the last selected mode does not work
- Blown fuse #5 or #17.
- The quality of the contact connections in the wiring of the corresponding circuit is broken (special attention should be paid to the ground loop).
- Faulty A/C control assembly.
Faulty data output on the display screen
- Blown fuse #5 or #17.
- The quality of the contact connections in the wiring of the corresponding circuit is broken (special attention should be paid to the ground loop).
- Faulty A/C control assembly.
Fan rotation stability is broken
- Blown fuse #5 or #17.
- The quality of the contact connections in the wiring of the corresponding circuit is broken.
- Faulty A/C control assembly.
- Fan motor defective.
- Faulty fan motor relay.
- Faulty power transistor or related fuse.
The functioning of the damper for turning on / off the circulation mode is broken
- The quality of the contact connections in the corresponding wiring is broken.
- Faulty A/C control assembly.
- Faulty electric motor or potentiometer for changeover flap actuator.
Function of switching of directions of distribution of air does not work
- The quality of the contact connections in the wiring of the corresponding circuit is broken.
- Faulty A/C control assembly.
- Faulty electric motor or selector damper drive potentiometer.
The function of maintaining the set temperature in the cabin does not work
- The quality of the contact connections in the wiring of the corresponding circuit is broken.
- Faulty A/C control assembly.
- Faulty electric motor or mixing damper drive potentiometer.
- The K/V relay is faulty.
- The K/V compressor is faulty.
- Heater defective.
- Faulty information sensors for temperature and / or intensity of solar radiation.
There is an excessive delay in the transition to the selected temperature setting
- Faulty electric motor or mixing damper drive potentiometer.
- Faulty information sensors for temperature and / or intensity of solar radiation.
Serviceability of functioning of fans К/В is broken
- Faulty main or auxiliary fan motor.
- Faulty main or auxiliary fan motor relay.
Clutch Troubleshooting
Clutch disengagement malfunction (when the pedal is depressed to the floor, it is difficult to engage / deactivate the reverse gear)
- Clutch pedal free travel adjusted.
- Oil has entered the clutch disc.
- «sank» diaphragm spring.
- Hydraulic fluid is leaking from the clutch master or slave cylinder.
- Air has entered the hydraulic circuit of the clutch actuator (there is softness of the pedal).
- The sealing cuff of the piston of the main or slave cylinder is damaged.
- There is a lack of lubrication in the guide bearing.
Clutch slips (engine speed increases without increasing vehicle speed)
- Clutch disc overheated - park the car and let the disc cool down.
- The friction linings of the driven disk are contaminated with oil seeping through the crankshaft rear oil seal.
- The new driven disk did not run in (for the final running-in of a new disk, at least 30–40 starts must be made).
- Deformed clutch/flywheel assembly.
- Weak diaphragm spring.
- Happened «sticking» piston in the clutch master cylinder due to foreign particles.
- Stuck clutch release mechanism.
- Deformed pressure plate or flywheel.
- Clutch hydraulic lines damaged.
Vibration occurs when the clutch is engaged
- Contaminated with oil, deformed, burned out, or polished to a shine friction linings of the driven disk / flywheel working surface.
- Friction lining fastening rivets loosened.
- The suspension mounts of the power unit are worn out, or their fastening is loose.
- The splines of the input shaft of the gearbox or the hub of the driven disk are worn out.
- Deformed clutch/flywheel assembly.
- There is a fatigue deformation of the diaphragm spring.
- Stuck pilot bearing in crankshaft journal.
When depressing or releasing the clutch pedal, there are extraneous noises
- Clutch pedal misadjusted.
- The release bearing is stuck on the transmission shaft.
- Worn or damaged pilot bearing.
- Cracked clutch disc.
- There is a fatigue deformation of the torsion springs of the clutch disc.
- Worn clutch basket assembly components.
- Pressure plate diaphragm spring broken.
- Worn or dry clutch pedal axle bushings.
- Faulty clutch basket assembly.
- Engine idle speed is too low.
Clutch pedal does not return to original position after releasing
- The functioning of the main or slave cylinder of the clutch is broken.
- Stuck piston in master or slave cylinder.
- Damaged or jammed clutch release drive components.
- Air has entered the hydraulic circuit.
Clutch pedal requires too much force to depress
- Stuck piston in master or slave cylinder.
- Faulty clutch basket assembly.
- Wrong size master or slave cylinder installed.
Diagnostics of malfunctions of a manual transmission
Gearbox in neutral makes noise when engine is running
- Worn input shaft bearings (noises appear when the clutch pedal is released and disappear when it is depressed).
- Gearbox drive shaft bearing worn.
- The transmission oil level has dropped.
- Worn clutch release bearing (noises appear when the clutch pedal is depressed and may decrease when it is released).
- The source of the noise may be variations in engine torque - adjusting the idle speed may correct the situation.
Noise occurs in all gears
Any of the above reasons and/or:
- Worn or damaged transmission output shaft or its bearings.
Noises occur in any particular gear
- Worn, chipped, or otherwise damaged transmission gear teeth.
- Synchronizers worn or damaged.
Noises occur when shifting gears
- Clutch malfunction.
- Faulty synchronizer assembly.
Box «jumps off» from selected gear
- Hardened gear lever collar.
- Shift drive components jammed.
- Worn gearshift mechanism.
- Loose bolts securing gearbox to engine
- Primary gear bearing retainer broken or loose.
- There is dirt between the clutch lever and the crankcase.
- Worn or damaged control balls, grooves in the spherical bearings of the shift fork rods, or control springs.
- The bearings of the driven or intermediate shaft are worn out.
- Worn power unit suspension mounts.
- Gear end play is excessive.
- Synchronizers worn out.
Transmission oil leaks
- An excessive amount of gear oil is poured into the box.
- Damaged oil seal (And) differential or speedometer seal.
Difficulty shifting gears
- Faulty clutch.
- Worn or damaged gearshift drive components.
- The transmission oil level has dropped.
- The transmission oil needs to be changed.
- Impact rod worn or damaged.
- Transmission gears jammed.
- Synchronizer blocks worn out.
There is a blocking of the box on any of the gears
- There is wear or a loose fit of the drive rod.
Diagnostics of malfunctions of automatic transmission
In view of the complexity of the AT design, it will be difficult for an average amateur mechanic to accurately diagnose its failures and restore repairs. In case of problems other than those listed below, the car owner should seek help from car service specialists. You should also not rush to dismantle a faulty transmission, as many of its checks are made in situ (at the regular place).
ATF leaks
- ATF is usually dark red in color - do not confuse traces of its leaks with those from engine oil (the latter can be carried to the transmission crankcase by the oncoming air flow).
- To identify the source of the leak, first of all, clean the transmission case and its surrounding surfaces from dirt and grease. Use a quality degreaser or steam clean the unit. Take the car for a short trip at low speed (so that traces of an existing leak are not carried far from its source). Jack up the car and place it on jack stands. Inspect the transmission case, visually identifying sources of ATF leakage. Most often these are:
- Transmission oil pan: Tighten fasteners and/or replace gasket;
- Transmission rear extension: tighten fasteners and/or replace oil seal;
- Filler neck: replace the rubber seal at the point where the filler neck enters the transmission case;
- Ventilation tube: transmission is overfilled and/or water has entered the crankcase;
- Speedometer connection unit: replace the O-ring at the entry of the drive cable into the transmission case.
ATF is brown or smells like burning
- The ATF level in the transmission has dropped, or the fluid is burnt and needs to be replaced.
- Faulty overdrive clutch.
- 2/4 gear brake band defective.
- Defective clutch of lower and reverse gears.
- Reverse clutch defective.
Transmission does not automatically downshift when the gas pedal is fully depressed (kickdown mode)
- Throttle cable misadjusted when kickdown is engaged.
Engine stalls while shifting gears
- Control valve defective.
- Blocking damper defective.
- Engine settings are broken.
- Transmission input shaft defective.
The engine is started in a transmission position other than «R or «N»
- The start enable switch is defective, or its adjustment is violated.
- Defective gear selector lever or gear selector drive.
In selector lever positions «P» or «N» there is an unusual noise
- The patency of the mesh filter is broken.
- Oil pump defective.
- Drive disk defective.
- Excessively high or insufficient ATF level.
Noises occur in position «D» selector lever
- Faulty main gear.
- Faulty planetary assembly.
- The brake tape of the lower and reverse gears is faulty.
- Reduction gear defective.
- The oil level in the differential is too high or too low.
The car is moving in position «N» selector lever
- Faulty transmission control module (TCM).
- Faulty lower gear clutch.
Switching from «N» on «D» or «R» accompanied by a push
- Faulty transmission control module (TCM).
- Faulty wiring.
- Control valve defective.
- Needs ATF replacement.
Switching from «N» on «D» or «R» runs with a delay
- Control valve defective.
- Line pressure solenoid valve failure.
- The sealing ring is worn out.
- Damaged front gasket crankcase AT.
- Defective clutch of lower and reverse gears.
- Reverse clutch defective.
The car does not move in any position AT (engine stalls)
- Parking brake engaged.
- Faulty planetary assembly.
The car does not move in any position AT (engine revs up)
- The strainer is clogged.
- The line pressure solenoid valve is malfunctioning.
- Control valve defective.
- Drive gear defective.
- Faulty hypoid gear.
- Drive shaft damaged.
- Differential defective.
- Oil pump defective.
- Input shaft defective.
- Output shaft defective.
- Faulty planetary gear.
- Drive disk defective.
- Too low ATF level.
- The front gasket of the AT case is damaged.
The car does not start only in the position «R» AT (engine stalls)
- Parking brake engaged.
- Faulty lower gear clutch.
- 2/4 gear brake band defective.
- Faulty planetary gear.
The car does not start only in the position «R» AT (engine revs up)
- Selector cable defective.
- Selector lever defective.
- Control valve defective.
- Defective clutch of lower and reverse gears.
- Reverse clutch defective.
The car does not move only in positions «D» And «3» AT (engine revs up)
- Faulty lower gear clutch.
- Overrunning clutch defective.
The car does not move only in positions «D», «3» And «2» AT (engine stalls)
- Reverse clutch defective.
The car does not start only in the provisions «D», «3» And «2» AT (engine revs up)
- Faulty lower gear clutch.
Engine starts only in position «R» selector
- Control valve defective.
Weak reception when accelerating from standstill
- Control valve defective.
- Faulty lower gear clutch.
- Reverse clutch defective.
- Too high or low ATF level.
- Oil pump defective.
- The front gasket of the AT case is damaged.
- Faulty torque converter lock-up clutch.
- Too high or low differential oil level.
Weak acceleration when accelerating from standstill
- Faulty transmission control module (TCM).
- Control valve defective.
- Faulty overdrive clutch.
- Faulty planetary gear.
- 2/4 gear brake band defective.
Transmission does not shift from 1st to 2nd gear
- Faulty transmission control module (TCM).
- Faulty throttle position sensor.
- Shift solenoid valve 1 defective.
- Faulty gas pedal position sensor.
- 2/4 gear brake band defective.
- Control valve defective.
No shifting from 2nd to 3rd gear
- Faulty transmission control module (TCM).
- Control valve defective.
- Faulty overdrive clutch.
- Shift solenoid valve 2 defective.
No shifting from 3rd to 4th gear
- Faulty transmission control module (TCM).
- Shift solenoid valve 1 defective.
- Faulty ATF temperature sensor.
- Control valve defective.
- 2/4 gear brake band defective.
Reduced engine braking efficiency in position «3» selector lever
- Faulty start/selector lever position switch.
- Faulty transmission control module (TCM).
- Control valve defective.
- Faulty throttle position sensor (TPS).
Reduced efficiency of engine braking in positions «3» or «2» selector lever
- Control valve defective.
Reduced engine braking efficiency in position «1» selector lever
- Defective clutch of lower and reverse gears.
The nature of the transmission shifts is broken
- Faulty start/selector lever position switch.
- Faulty transmission control module (TCM).
- Faulty throttle position sensor (TPS).
- Control valve defective.
- The quality of grounding is broken.
No transmission lockup
- Faulty transmission control module (TCM).
- Faulty throttle position sensor (TPS).
- Faulty ATF temperature sensor.
- Control valve defective.
- The serviceability of issuing a signal of engine speed is violated.
The parking brake does not securely fix the vehicle / the selector lever is difficult to move out of position «P»
- Selector cable defective.
- Selector lever defective.
- Parking brake mechanism defective.
Shifting from 1st to 2nd gear is accompanied by jerks
- Faulty transmission control module (TCM).
- Faulty throttle position sensor (TPS).
- Switchover solenoid valve 2/4 defective.
- Faulty ATF temperature sensor.
- The line pressure solenoid valve is malfunctioning.
- Control valve defective.
- 2/4 gear brake band defective.
- ATF needs to be replaced.
- Engine settings are broken.
- 2/4 gear brake synchronizing solenoid valve defective.
Switching from 1st to 2nd gear is accompanied by transmission slip
- Faulty transmission control module (TCM).
- Faulty throttle position sensor (TPS).
- Switchover solenoid valve 2/4 defective.
- Faulty ATF temperature sensor.
- The line pressure solenoid valve is malfunctioning.
- Control valve defective.
- 2/4 gear brake band defective.
- 2/4 gear brake synchronizing solenoid valve defective.
- Faulty overdrive clutch.
Shifting from 2nd to 3rd gear is accompanied by jolts
- Faulty transmission control module (TCM).
- Faulty throttle position sensor (TPS).
- Switchover solenoid valve 2/4 defective.
- Faulty ATF temperature sensor.
- The line pressure solenoid valve is malfunctioning.
- Control valve defective.
- Faulty overdrive clutch.
- 2/4 gear brake band defective.
- ATF needs to be replaced.
- Engine settings are broken.
- 2/4 gear brake synchronizing solenoid valve defective.
Switching from 2nd to 3rd gear is accompanied by transmission slip
- Faulty transmission control module (TCM).
- Faulty throttle position sensor (TPS).
- Switchover solenoid valve 2/4 defective.
- Faulty ATF temperature sensor.
- The line pressure solenoid valve is malfunctioning.
- Control valve defective.
- Faulty overdrive clutch.
- 2/4 gear brake band defective.
- 2/4 gear brake synchronizing solenoid valve defective.
Shifting from 3rd to 4th gear is accompanied by jolts
- Faulty transmission control module (TCM).
- Faulty throttle position sensor (TPS).
- Switchover solenoid valve 2/4 defective.
- Faulty ATF temperature sensor.
- The line pressure solenoid valve is malfunctioning.
- Control valve defective.
- 2/4 gear brake synchronizing solenoid valve defective.
- 2/4 gear brake band defective.
- ATF needs to be replaced.
- Engine settings are broken.
- Faulty synchronizing solenoid valve low clutch solenoid valve.
- Faulty lower clutch.
Switching from 3rd to 4th gear is accompanied by transmission slip
- Faulty transmission control module (TCM).
- Faulty throttle position sensor (TPS).
- Switchover solenoid valve 2/4 defective.
- Faulty ATF temperature sensor.
- The line pressure solenoid valve is malfunctioning.
- Control valve defective.
- 2/4 gear brake band defective.
- 2/4 gear brake synchronizing solenoid valve defective.
Translation of the selector lever from the position «3» into position «2» accompanied by jerks
- Faulty transmission control module (TCM).
- Faulty throttle position sensor (TPS).
- Faulty ATF temperature sensor.
- The line pressure solenoid valve is malfunctioning.
- Control valve defective.
- Switchover solenoid valve 2/4 defective.
- 2/4 gear brake band defective.
- ATF needs to be replaced.
- 2/4 gear brake synchronizing solenoid valve defective.
Translation of the selector lever from the position «D» into position «1» accompanied by jerks
- Faulty transmission control module (TCM).
- Faulty throttle position sensor (TPS).
- Faulty ATF temperature sensor.
- The line pressure solenoid valve is malfunctioning.
- Control valve defective.
- ATF needs to be replaced.
- Switchover solenoid valve 2/4 defective.
- 2/4 gear brake synchronizing solenoid valve defective.
- Low clutch synchronizing solenoid valve defective.
Translation of the selector lever from the position «2» into position «1» accompanied by jerks
- Faulty transmission control module (TCM).
- Faulty throttle position sensor (TPS).
- Faulty ATF temperature sensor.
- The line pressure solenoid valve is malfunctioning.
- Control valve defective.
- Defective clutch of lower and reverse gears.
- ATF needs to be replaced.
- Switchover solenoid valve 2/4 defective.
- 2/4 gear brake synchronizing solenoid valve defective.
- Low clutch synchronizing solenoid valve defective.
Releasing the gas pedal at medium speeds is accompanied by jolts
- Faulty transmission control module (TCM).
- Faulty throttle position sensor (TPS).
- Faulty ATF temperature sensor.
- The line pressure solenoid valve is malfunctioning.
- Control valve defective.
- Defective lock damper.
- Engine settings are broken.
- Switchover solenoid valve 2/4 defective.
- 2/4 gear brake synchronizing solenoid valve defective.
- Low clutch synchronizing solenoid valve defective.
Rectilinear motion is accompanied by an increased level of vibration
- Faulty transmission control module (TCM).
- Faulty lockout solenoid valve.
- Defective lock damper.
Vibrations occur when making turns
- Faulty transmission control module (TCM).
- Faulty front speed sensor (VSS).
- Faulty rear speed sensor (VSS).
- Faulty throttle position sensor (TPS).
- Faulty ATF temperature sensor.
- ATF needs to be replaced.
- Defective transfer box clutch.
- Transfer case valve defective.
Starting the car is accompanied by slipping of the front wheels
- Faulty transmission control module (TCM).
- Faulty front VSS.
- Faulty sensor-switch for activating the all-wheel drive mode (FWD).
- Faulty throttle position sensor (TPS).
- Faulty ATF temperature sensor.
- Control valve defective.
- ATF needs to be replaced.
- Dispenser clutch defective.
- Dispenser valve defective.
- The patency of the tube of the dispensing mechanism is broken.
The car is not translated into all-wheel drive mode (FWD)
- Faulty transmission control module (TCM).
- Faulty sensor-switch for activating the all-wheel drive mode (FWD).
- Dispenser clutch defective.
- Dispenser valve defective.
Transmission «jumps off» from the selected position, shifting is difficult or noisy, or does not provide translational movement of the car forward or backward
- There are many possible causes of these failures, but only one of them falls within the purview of the average amateur mechanic - a violation of the ATF level. Check, if necessary, adjust the level / replace the fluid and filter, in parallel check the condition of the ATF. In all other cases, the car should be driven away for diagnostics and reconditioning / replacement of the transmission to a service station.
Diagnosis of cardan shaft malfunctions
There are leaks at the front of the propeller shaft
- Damaged or worn transmission rear oil seal. Also check the condition of the sliding collar surface.
When you turn on the transmission (at the moment of loading) there is a knock
- Loose rear suspension components.
- Sliding clamp spindle worn.
- Loose propeller shaft bolts/nuts.
- Worn or damaged universal joint bearings (ov).
- Worn center bearing/center support pad.
There is a metallic rattle, consistent with the speed of the car
- Worn cardan bearings (ov).
There are vibrations
First of all, check the wheel balance and tire inflation pressure. Usually the vibrations increase with the increase in motion.
- Install a tachometer in the passenger compartment and while driving, try to determine the engine speed at which the vibration reaches its maximum intensity, then shift the gear and bring the engine speed to the same value.
- If vibration occurs and reaches its maximum intensity at the same engine speed, regardless of the selected gear, its source is not the cardan shaft, since its rotation frequency depends on the choice of gear ratio.
- If a gear change causes the vibration to disappear or noticeably decrease its intensity (at the same engine speed), you should proceed to check the condition of the cardan shaft:
- Check the cardan shaft for signs of bending and other deformations, replace if necessary;
- Thoroughly clean the shaft, - adhering dirt can cause imbalance;
- Assess the degree of wear of the bearings of the cardan joints, if necessary, replace the assemblies;
- Check the balance of the cardan shaft or its connecting flange. Make sure that the balancing weights are in place, remove the shaft and install it by turning it 180°- if the vibrations do not disappear, give the shaft to balancing;
- Check up reliability of a tightening of fixing bolts/nuts;
- Assess the degree of wear of the central bearing;
- Check the condition of the rear transmission bushings.
There is a scraping sound
- Make sure the sliding yoke dust cover does not rub against the transmission rear extension housing.
There is a howl or whistle
- The source of such sounds may be the central bearing.
Diagnosis of malfunctions of the rear axle and final drive
There is extraneous noise, the same when driving in gear and coasting
- Natural road noise.
- Excessive differential gear play.
- Excessive hypoid gear play.
- Loose or missing pinion nut.
- Worn or incorrectly inflated tires.
- Worn or damaged wheel bearings, or their tightness is loose.
- The oil level in the differential dropped.
- Differential defective.
There is a knock that occurs when starting off or when shifting gears
- The differential is faulty or its adjustment is broken.
Extraneous sounds occur when making turns
- Differential defective.
- Thrust washer excessively worn.
- Slip clutch stuck or damaged.
There are oil leaks
- Clogged or damaged breather.
- Loose or missing differential axle or side retainer bolts, or O-ring installed incorrectly.
- Loose or missing rear cover bolts or damaged rear cover gasket.
- The oil filter is out of order, or weakened (lost) drain plug.
There are vibrations
- See the subsection on diagnosing driveshaft problems. If the shaft is in order, jack up the rear of the car and place it on props and manually assess the condition of the wheel bearings, replace if necessary.
There are oil leaks
- Main gear drive gear seal damaged.
- Damaged axle seals.
- Loose fasteners or damaged differential cover gasket.
- Loose differential drain or fill/check plug.
- The patency of the ventilation breather of the differential is broken.
Transfer case troubleshooting (with appropriate vehicle equipment)
Gears jump out of gear
- The amount of free travel of the control lever is violated.
- The control lever clings to the console.
- The fasteners of the transfer box suspension supports are loose, or fatigue deformation of the material occurs.
- Worn internal components of the transfer case, or the adjustments are violated.
Difficulty switching modes
- The oil level has dropped.
- Worn internal components of the transfer case, or the adjustments are violated.
There are extraneous noises
- The oil level in the transfer case has dropped.
- The presence of noise when selecting any of the modes indicates a malfunction in the components of the rear differential or rear axle.
Diagnostics of malfunctions of the brake system
Before concluding that the brake system has failed, check the condition and inflation pressure of the tires, the vehicle's load evenness, and the front wheel alignment.
When braking, the directional stability of the car is violated
- Tires incorrectly inflated.
- The adjustment of the angles of installation of the front wheels is broken.
- One vehicle axle (front or back) Fitted with wheels of different sizes.
- Worn, damaged or oily brake pads / shoes from one of the sides of the car.
- Excessively worn brake pads or a disc from one of the sides of the car.
- Loose fasteners of the front suspension components.
- One or more brake mechanisms are faulty.
- Broken brake lines.
- Loose caliper or brake shield mounting bolts.
- The caliper/wheel cylinder piston of one of the brake mechanisms is stuck, or its movement is difficult.
- Brake pads / shoes with friction linings of various types are installed on different sides of the car.
- Worn or damaged steering or suspension components.
- The wheel bearing preload is out of adjustment.
Extraneous noises occur during braking (grinding or high-frequency squealing)
- The friction linings of the brake pads of the front wheels are worn out - the sound is emitted by the wear sensors of the pads.
- Dirty or polished brake pads.
- Oil has been spilled onto the working surface of the brake pad (clicks are heard).
- Damaged brake disc / drum - usually after a long parking of the car.
- A foreign object has fallen between the disc and the shield of the brake mechanism (e.g. stone).
- The brake shield is deformed.
Excessive brake pedal travel
- There is a local violation in the brake system.
- The hydraulic fluid level in the GTZ reservoir has dropped.
- Air has entered the hydraulic system.
- Serviceability of functioning of automatic regulators of brake mechanisms is broken.
- Defective restrictor valve.
- Faulty GTC.
- The vacuum brake booster is faulty.
There is a softness of the brake pedal when it is squeezed out
- Air has entered the hydraulic system.
- Flexible brake hoses damaged as a result of material aging.
- Loose fasteners GTZ.
- Faulty GTC.
- The setting of the working clearances of the brake pads / shoes is violated.
- The patency of the ventilation hole of the GTZ reservoir cover is broken.
- Deformed rubber brake lines.
- Caliper seals softened.
- Brake fluid needs to be replaced.
Applying too much force to the brake pedal is required to stop the vehicle
In addition to the reasons listed in the previous subsection:
- The vacuum brake booster is defective.
- Friction linings of brake pads/boots are excessively worn.
- Piston stuck (And) caliper/wheel cylinder.
- Friction linings of brake pads/boots contaminated with oil or grease.
- Damaged or worn brake discs.
- Faulty GTZ or caliper (s) / wheel cylinder (s).
- Recently installed and did not have time to run in new brake pads / shoes.
- There is a local violation in the brake system.
Foot brake pedal sinks to the floor with no resistance
- The fluid level in the GTZ reservoir has dropped, or there are leaks through the pistons of the calipers / wheel cylinders.
- Brake lines damaged or loose fittings.
During braking, the foot brake pedal pulsates
- Worn or damaged wheel bearings or misadjusted preload.
- The brake caliper components are installed incorrectly, or foreign objects have fallen between them.
- Excessive brake disc lateral runout/drum ovality.
- Brake pads worn unevenly.
There is a pulsation of the foot brake pedal when it is squeezed out during hard braking
- A consequence of the correct functioning of the ABS.
During braking, vibration is transmitted to the brake pedal or steering wheel
- There is excessive brake disc runout/brake drum deformation.
- Friction linings of brake pads/boots are worn out.
- Loose caliper/brake plate mounting bolts.
- Worn suspension or steering components or bearings.
Brakes «seized» (reduced efficiency of the engine output, the wheels heat up excessively while driving)
- Adjustment of an output rod of a pedal of a foot brake is broken.
- The patency of the GTZ inlet fitting is broken.
- The GTZ piston is stuck in the cylinder.
- Excessively worn brake pads/boots.
- The piston cups in the main brake cylinder or brake calipers are deformed.
- Parking brake adjustment out of order.
- The wheel bearing preload is out of adjustment.
- The adjustment of the installation height of the foot brake pedal is broken.
- Stuck wheel cylinder (s).
- The adjustment of the clearances of the landing of the shoes in the drums of the brake mechanisms is violated.
- Faulty GTC.
- Broken brake lines.
Rear wheels lock up under normal braking
- Tires are over-inflated.
- Excessively worn protectors.
Rear wheels lock up during emergency braking
- Tires are over-inflated.
- The protectors are worn too much.
- The brake pads of the front wheels are contaminated with oil.
- Faulty GTZ, or assembly (And) brake mechanisms.
«tacked» parking brake
- Parking brake lever not adjusted.
- The parking brake cable does not move.
- Parking brake shoe clearance not adjusted.
- Return spring broken.
Noise from parking brake mechanism
- Return spring broken.
- Parking brake pad retaining spring broken.
The parking brake does not hold the vehicle properly
- The adjustment of the parking brake drive is broken.
Diagnosis of malfunctions of the recoil device
Attention! If the car does not move (brake is not released) due to a broken return spring, loosen the adjusting nut, disconnect the clutch and the pressure holding valve (PHV), then release the brakes by retracting the PHV lever.
Before proceeding with this operation, make sure that the parking brake is engaged.
The wheel chock does not work on slopes with a slight slope.
Clutch pedal depressed with excessive resistance
- Defective pressure holding valve cable (PHV).
- Faulty PHV lever.
- Faulty clutch.
The vehicle is not held still on a slope greater than 3%
- The front part of the car body is excessively lowered.
- Broken or stretched PHV drive cable.
- Excessive clutch pedal free play.
- PHV seal broken (valve must be replaced as an assembly).
Starting the car is accompanied by a push
- Foot brake pedal pressed too hard (the more force the pedal is depressed, the later the chock is released).
- When starting off on a level surface, the vehicle may initially jerk backwards as a result of the activation of the wheel chock.
Car slips on start
- Worn clutch disc.
- Pressure holding valve cable extended (PHV).
- Deformed cable assembly support bracket or PHV valve stem.
The car cannot start moving at start
- Stretched or broken return spring.
- Pressure holding valve lever (PHV) does not return to its original position.
An unusual sound occurs when the foot brake pedal is released
- The pads are pressed too hard against the brake disc as a result of hard braking.
Clutch pedal makes unusual sound when depressing
- The recoil spring hook or the movable section of the PHV drive cable end is not well lubricated.
- Faulty clutch.
Diagnosis of malfunctions of the anti-lock brake system (ABS)
Loss of directional stability when braking (the car pulls to one side or turns)
- Faulty hydraulic modulator/ABS control unit solenoid valve.
- Faulty ABS sensor.
- Faulty brakes/pads.
- The correct connection of the hydraulic lines / electrical wiring is violated.
- The adjustment of the angles of installation of the front wheels is broken.
- One vehicle axle (front or back) Fitted with wheels of different sizes.
- Wrong (uneven) tires are inflated.
- Faulty hydraulic modulator of the dynamic stabilization system (VDC).
- Faulty VDC control module.
- Rough road.
Excessive braking distance
- Faulty hydraulic modulator/ABS control unit solenoid valve.
- Faulty ABS sensor.
- Air has entered the brake system.
- One vehicle axle (front or back) Fitted with wheels of different sizes.
- Wrong (uneven) tires are inflated.
Wheels lock up prematurely
- Faulty hydraulic modulator/ABS control unit solenoid valve.
- Faulty ABS sensor.
- Faulty brakes/pads.
- The correct connection of the hydraulic lines / electrical wiring is violated.
Brakes «seized»
- Faulty hydraulic modulator/ABS control module solenoid valve.
- Faulty ABS sensor.
- Faulty brake master cylinder (GTZ).
- Faulty brakes (e.g. a stuck piston).
- The correct connection of the hydraulic lines / electrical wiring is violated.
- Parking brake adjustment out of order.
- The adjustment of the pedal stroke of the foot brake is broken.
- Wheel alignment out of alignment.
- One vehicle axle (front or back) wheels of different sizes are installed.
Excessive foot brake pedal travel
- Corresponding adjustment is violated.
- Air has entered the brake system.
- The correct connection of the hydraulic lines / electrical wiring is violated.
When braking, the car buries its nose excessively
- Faulty hydraulic modulator/ABS control module solenoid valve.
- Faulty ABS sensor.
- Suspension components worn or damaged or loose.
- Faulty brakes/pads.
- The correct connection of the hydraulic lines / electrical wiring is violated.
- Wheel alignment out of alignment.
- One vehicle axle (front or back) Fitted with wheels of different sizes.
- Tires incorrectly inflated.
- Rough road.
Vibration of the foot brake pedal when braking on a slippery road
- Normal sign of ABS operation (when braking).
- Uneven road surface.
The functioning of the ABS hydraulic modulator is accompanied by extraneous noise
- Faulty hydraulic modulator support sleeve.
- Faulty ABS sensor.
- Damaged brake lines.
When driving on slippery surfaces, there are noises in the front of the car
- Faulty ABS hydraulic modulator support sleeve.
- Faulty ABS sensor.
- Faulty GTC.
- Faulty brakes/pads.
- The hydraulic lines of the brake path are faulty.
- Defective brake booster/control valve.
- Suspension components worn or damaged or loose.
When driving on slippery surfaces, there are noises in the rear of the car
- Faulty ABS sensor.
- Faulty brakes/pads.
- Parking brake defective.
- The hydraulic lines of the brake path are faulty.
- Suspension components worn or damaged or loose.
Diagnostics of malfunctions of the dynamic stabilization system (VDC) / traction control (TCS)
Excessive braking distance
- Faulty hydraulic modulator of the dynamic stabilization system (VDC).
- Faulty VDC control module.
- Faulty brakes/pads.
- Air has entered the brake system.
- One vehicle axle (front or back) Fitted with wheels of different sizes.
- Tires incorrectly inflated.
- Brake lines/wiring incorrectly connected.
- The ABS sensor is faulty, or its working gap is incorrectly set.
- The rotation angle sensor is faulty or its neutral position is incorrectly set.
- Faulty yaw/lateral g-force sensor.
- Defective pressure relief valve.
- Faulty GTC.
- The vacuum brake booster is defective.
- The lines of the hydraulic path of the brake system are faulty.
Wheels lock up prematurely
- Faulty hydraulic modulator of the dynamic stabilization system (VDC).
- Faulty VDC control module.
- Faulty ABS sensor.
- Faulty brakes/pads.
- The correct connection of the hydraulic lines / electrical wiring is violated.
- The rotation angle sensor is faulty or its neutral position is incorrectly set.
- Defective pressure relief valve.
- The lines of the hydraulic path of the brake system are faulty.
Brakes «seized»
- Faulty hydraulic modulator of the dynamic stabilization system (VDC).
- Faulty VDC control module.
- Faulty ABS sensor.
- Faulty GTC.
- The parking brake has failed.
- Foot brake pedal not adjusted.
- The rotation angle sensor is faulty or its neutral position is incorrectly set.
- Faulty brakes/pads.
- The lines of the hydraulic path of the brake system are faulty.
Excessive foot brake pedal travel
- Corresponding adjustment is violated.
- Air has entered the brake system.
- Faulty hydraulic modulator of the dynamic stabilization system (VDC).
- Defective pressure relief valve.
- Faulty GTC.
- Faulty brakes/pads.
- The lines of the hydraulic path of the brake system are faulty.
- The vacuum brake booster is defective.
When braking, the car buries its nose excessively
- Faulty hydraulic modulator of the dynamic stabilization system (VDC).
- Faulty VDC control module.
- Faulty ABS sensor
- Faulty brakes/pads.
- One vehicle axle (front or back) Fitted with wheels of different sizes.
- Tires incorrectly inflated.
- The correct connection of the hydraulic lines / electrical wiring of the brake system is violated.
- Rough road.
- The rotation angle sensor is faulty or its neutral position is incorrectly set.
- Faulty GTZ
- The lines of the hydraulic path of the brake system are faulty.
- Suspension components worn or damaged or loose.
Excessive vibration of the foot brake pedal Vibration occurs when braking hard, accelerating or driving on slippery roads
- Rough road.
- The correct connection of the hydraulic lines / electrical wiring of the brake system is violated.
- Faulty hydraulic modulator of the dynamic stabilization system (VDC).
- Defective pressure relief valve.
- The vacuum brake booster is defective.
The operation of the VDC hydromodulator is accompanied by extraneous noise
- Worn hydromodulator support bushing.
- Faulty hydraulic modulator.
- Faulty ABS sensor.
- Faulty or incorrectly installed yaw/lateral g-force sensor.
- The lines of the hydraulic path of the brake system are faulty.
- The rotation angle sensor is faulty or its neutral position is incorrectly set.
Hard braking, accelerating and driving on slippery roads cause noises in the front of the vehicle
- Faulty hydraulic modulator of the dynamic stabilization system (VDC).
- Faulty ABS sensor.
- The GTS is out of order.
- Faulty brakes/pads.
- The lines of the hydraulic path of the brake system are faulty.
- The vacuum brake booster failed.
- One vehicle axle (front or back) Fitted with wheels of different sizes.
- Tires incorrectly inflated.
Noises occur inside the car
- The control module of the dynamic stabilization system is faulty (VDC);
- The rotation angle sensor is faulty or its neutral position is incorrectly set.
Hard braking, accelerating and driving on slippery roads cause noises in the front of the vehicle
- Faulty ABS sensor.
- Faulty brakes/pads.
- Parking brake defective.
- Suspension components are excessively worn or damaged or loose.
- Damaged axles.
- Wheels damaged.
- Custom tires fitted.
Engine does not accelerate or stalls when accelerating hard or when driving on slippery roads
- Faulty hydraulic modulator of the dynamic stabilization system (VDC).
- Faulty VDC control module.
- Faulty ABS sensor
- Faulty GTC.
- The parking brake has failed.
- The correct connection of the hydraulic lines / electrical wiring of the brake system is violated.
- The rotation angle sensor is faulty or its neutral position is incorrectly set.
- Faulty brakes/pads.
- The lines of the hydraulic path of the brake system are faulty.
The dynamic stabilization system is activated under normal driving conditions
- Faulty hydraulic modulator of the dynamic stabilization system (VDC).
- Faulty VDC control module.
- Faulty ABS sensor.
- The rotation angle sensor is faulty or its neutral position is incorrectly set.
- Bad brakes (brake pads).
- Faulty brakes/pads.
- Wheel alignment out of alignment.
- One vehicle axle (front or back) Fitted with wheels of different sizes.
- Tires incorrectly inflated.
- Rough road.
- Malfunctions in the power steering system (power steering).
- The correct connection of the hydraulic lines / electrical wiring of the brake system is violated.
VDC disconnect indicator light does not light when the switch is pressed «VDC OFF»
If the switch «VDC OFF» keep pressed for 10 seconds or more while the motor is running, the VDC disconnect indicator will turn off permanently. To return to the working position, you must turn off and then turn on the ignition.
- Faulty hydraulic modulator of the dynamic stabilization system (VDC).
- Faulty VDC control module.
Suspension and steering fault diagnosis
Before testing suspension and steering components, verify that the problem is not caused by improper tire inflation, mismatched tire sizes, wheel imbalance, or «tacking» brakes.
Violated directional stability of the car
- Wheels of different sizes are installed on one axle, or their tires are inflated with different pressures.
- Tires are defective.
- Worn suspension or steering components.
- The adjustment of the angles of installation of the front wheels is broken.
- «tacked on» front wheel brakes.
- The wheel bearing preload is out of adjustment.
- broken or «sank» coil springs (with appropriate vehicle equipment).
- Loose wheel nuts.
- The geometry of the suspension or steering gear is broken as a result of an accident.
There is wheel play and increased vehicle vibration
- Front wheel imbalance (vibration is transmitted most noticeably through the steering wheel).
- Rear wheel imbalance (vibration is transmitted most noticeably through the body of the car).
- Tires are unevenly inflated.
- The wheel bearing preload is out of adjustment.
- Worn suspension strut components.
- Loose wheel nuts.
- Damaged or deformed wheels.
- Tires damaged.
- Worn steering or suspension components, or their ball joints and/or rubber bushings.
- Worn ball joint (s).
During cornering and braking, «galloping» and/or vehicle rocking
- The anti-roll bar has loosened.
- Shock absorbers faulty.
- broken or «sank» coil springs / suspension springs.
- Worn steering or suspension components, or their ball joints and/or rubber bushings.
- The car is overloaded.
There is yaw or general vehicle yaw
- Wheels of different sizes are installed on one axle, or their tires are inflated with different pressures.
- Wheel balance out of alignment.
- Tires unevenly inflated.
- Loose wheel nuts.
- There is a lack of lubrication of CV joints and tie rod ends.
- Worn shock absorbers.
- The anti-roll bar has loosened.
- broken or «sank» coil springs/springs.
- The adjustment of the angles of installation of the front wheels is broken.
- Worn steering or suspension components, or their ball joints and/or rubber bushings.
Steering wheel too hard to turn
- The fluid level of the power steering system has dropped.
- Tires incorrectly inflated.
- There is a lack of lubrication of ball bearings and tie rod ends.
- The adjustment of the angles of installation of the front wheels is broken.
- The steering mechanism is out of adjustment, or the lubrication level has dropped.
- The wheel bearing preload is out of adjustment.
- Worn or damaged steering components.
- The rotation of the steering shaft is hindered by the turn signal switch.
- Tires are too lightly inflated.
- The lubricant has deteriorated. Replace.
- Worn or damaged ball joints.
- Worn or damaged steering components.
Excessive steering wheel play
- Loose wheel bearings.
- Worn bushings of suspension components.
- Steering gear out of alignment.
- The adjustment of the angles of installation of the front wheels is broken.
- Loose steering gear assembly.
- Worn steering or suspension components.
No hydraulic boost
- The steering pump drive belt is damaged, or its tension adjustment is broken.
- The hydraulic fluid level has dropped.
- The patency of the power steering system hoses is broken.
- Air has entered the hydraulic path of the power steering system.
- Steering pump defective.
- Steering gear defective.
Serviceability of return of a steering wheel in a straight line position is broken
- The adjustment of the angles of installation of the front wheels is broken.
- Tires are too lightly inflated.
- Worn steering components.
- Steering column adjustment is broken.
- Worn or damaged ball joints.
- Worn or damaged steering components.
- Steering gear components have lost lubrication.
- The level of lubrication in the crankcase of the steering mechanism has fallen.
- Steering column jammed.
The steering wheel rotates in different directions with different resistance
- There are leaks in the steering gear housing.
- The patency of the hydraulic lines of the power steering system is broken.
The operation of the steering pump is accompanied by an increased background noise
- There is a lack of oil in the pump.
- The patency of the hoses or the steering pump oil filter is broken.
- Loose drive pulley.
- The adjustment of the tension force of the steering pump drive belt is broken.
- Steering pump defective.
There are extraneous noises coming from the front of the car
- Tires incorrectly inflated.
- There has been a loss of lubrication of the ball joints or steering gear components.
- Loose steering gear, steering and suspension components.
- Worn shock absorber mounts.
- Dampers damaged.
- Springs damaged.
- Loose wheel nuts.
- Worn or damaged rear axle splines.
- Excessive axial play of the rear axle.
Decreased vehicle control during braking
- Worn front wheel bearings.
- broken or «sank» coil springs / suspension springs.
- Warped brake discs/drums.
The car sank excessively
- Overload
- Shock absorbers worn out rack assemblies.
- broken or «sank» coil springs / suspension springs.
- Serviceability of functioning of an electropneumatic suspension bracket is broken (with appropriate equipment).
There is a grinding or other extraneous noise emitted by the steering mechanism
- Loose rack and pinion assembly fasteners.
- There is internal damage to the steering gear.
Excessive tire wear
Increased wear on the inside or outside of the tread
- Tires under-inflated (wear on both ends).
- The adjustment of the angles of installation of the front wheels is broken.
- Worn steering or suspension components, or their ball joints and/or rubber bushings.
- No speed reduction when cornering.
- There is a mechanical violation of the geometry of the suspension as a result of the accident.
Scale wear (fraying) protector
- Convergence setting violated.
Wear of the central part of the tread
- Tires are over-inflated.
Wear on the inner and outer edges of the tread
- Tires under-inflated.
- Worn shock absorbers.
Uneven tread wear
- Tire/wheel out of balance.
- Excessive wheel or tire lateral runout.
- Worn shock absorbers.
- Tire damaged.
Diagnostics of malfunctions of the tempostat
The main tempostat switch does not turn on
- Check nutrition.
- Check the main tempostat switch.
Tempostat not set
- Check the SET/COAST switch.
- Check the brake and parking light switch
- Check clutch switch (RKPP).
- Check ignition switch (AT).
- Check vehicle speed sensor (VSS).
The engine does not maintain the set speed±3 km / h
- Check vehicle speed sensor.
Vehicle speed does not increase or return to the set speed after pressing the RESUME/ACCEL switch
- Check the RESUME/ACCEL switch.
Vehicle speed does not decrease after pressing the SET/COAST switch
- Check the SET/COAST switch.
Tempostat does not turn off after pressing the CANCEL switch
- Check the CANCEL switch.
Tempostat does not turn off after releasing the brake pedal
- Check the brake and parking light switch.
Tempostat does not turn off after releasing the clutch pedal (RKPP)
- Check clutch switch.
Diagnostics of failures of onboard electrical equipment
One or both headlights are malfunctioning in low or high beam mode
- The quality of the contact connection on the connector is broken. Check the quality of the grounding of the headlight and the serviceability of the power supply to it from the battery. If the power is good and the ground is good, replace the failed lamp. If there is a power/ground fault, check the condition of the wiring in the relevant circuit (see wiring diagrams).
- Control switch defective.
The brightness of one or both headlights is severely reduced
- The quality of the contact connection on the connector is broken. Check the quality of the grounding of the headlight and the serviceability of the power supply to it from the battery. If the supply voltage at the connector is very low, check the condition of the elements and the connecting wiring of the corresponding circuit (see wiring diagrams).
- The base of the corresponding lamp or its socket is badly oxidized. Thoroughly clean the contact surfaces, if necessary, replace the failed component.
Running and marker lights
Running and parking lights do not work
- The quality of the contact connection on the connector is broken. Check the grounding of the corresponding lighting fixture and the correct battery power supply. If the power is supplied properly and the grounding is in order, check the condition of the cartridge, if necessary, replace the failed lamp. If there is a power/ground fault, check the condition of the wiring in the relevant circuit (see wiring diagrams).
- Control switch defective. Make a replacement.
There are intermittent failures of navigation and position lights
- The filament of the corresponding lamp is damaged. Check, replace the failed lamp.
- The base of the corresponding lamp or its socket is badly oxidized. Thoroughly clean the contact surfaces, if necessary, replace the failed component.
- Damaged wiring or its contact terminals. Check and make appropriate corrections.
- Control switch defective. Make a replacement.
The brightness of the glow of one of the lighting fixtures is greatly reduced
- The quality of the contact connection on the connector is broken. Check the grounding of the corresponding lighting fixture and the correct battery power supply. If the supply voltage at the connector is very low, check the condition of the elements and the connecting wiring of the corresponding circuit (see wiring diagrams).
- The base of the corresponding lamp or its socket is badly oxidized. Thoroughly clean the contact surfaces, if necessary, replace the failed component.
- Control switch defective. Make a replacement.
Interior lighting fixtures
Interior lighting not working
- The control switch is set to the wrong position. Find the switch and move it to the appropriate position.
- The quality of the contact connection on the lamp connector is broken. Check the grounding and battery power supply. If there is no power, check the condition of the appropriate fuse and replace if necessary. Check the condition of the elements and connecting wiring of the corresponding circuit (see wiring diagrams). If there is no grounding, check the condition of the contacts of the door sensors-switches, remove traces of corrosion, if necessary, replace the defective components.
There is an intermittent failure of interior interior lighting
- The filament of the corresponding lamp is damaged. Check, replace the failed lamp.
- The base of the corresponding lamp or its socket is badly oxidized. Thoroughly clean the contact surfaces, if necessary, replace the failed component.
- The contact terminals of the external connector of the lamp are oxidized or damaged. Check, clean or replace the relevant components.
- The function of the door sensors-switches is broken. Check and replace failed components.
The brightness of the interior lighting is greatly reduced
- The quality of the contact connection on the connector is broken. Check the quality of the grounding of the lamp and the serviceability of the supply of battery power to it. If the supply voltage at the connector is very low, check the condition of the elements and the connecting wiring of the corresponding circuit (see wiring diagrams).
- The base of the corresponding lamp or its socket is badly oxidized. Thoroughly clean the contact surfaces, if necessary, replace the failed component.
- One of the control switches/sensors is faulty. Make a replacement.
Stop lights
There is a failure of one of the brake lights
- The serviceability of the voltage supply to the lamp of the corresponding brake light is broken. check if the power is supplied properly, evaluate the quality of the ground, if necessary, replace the lamp. If there are signs of a break in the power circuit or ground, check the condition of the elements and the connecting wiring of the corresponding circuit (see wiring diagrams).
Both brake lights fail
- The adjustment of the sensor-switch of brake lights is violated. Check and make appropriate adjustments. If the power supply to the brake lights remains broken, despite the correct functioning of the sensor-switch, check the condition of the elements and the connecting wiring of the corresponding circuit (see wiring diagrams), make the necessary corrections.
The brightness of one or both brake lights is severely reduced
- The quality of the contact connection on one of the contact connectors of the corresponding circuit is broken. Check the quality of the grounding of the lamp assemblies and the serviceability of the supply of battery power to them. If the supply voltage at the connector is very low, check the condition of the elements and the connecting wiring of the corresponding circuit (see wiring diagrams). Sometimes it becomes necessary to remove a defective connector and clean its seating surface.
Pilot lamps / indicator lights
Pilot lamp (s) stays on after starting the engine.
Charge control lamp
- Faulty alternator or voltage regulator. Check and replace failed components.
- There is a short circuit in the corresponding lamp wiring circuit. Check and make any necessary corrections.
MIL failure warning lamp («Check engine»)
- The time has come for the next maintenance of the engine, or the settings of the latter are violated. Carry out maintenance, check the settings, evaluate the condition of the spark plugs and air filter, check the level and condition of the engine oil. Make the necessary adjustments and replacements.
- There is an intermittent re-leaning of the air-fuel mixture as a result of approaching the end of the fuel supply in the tank. Fill the car with fuel, reset the lamp.
- The quality of the contact connections in the injection / engine control circuit is broken. Check the condition of the wiring and connectors of the control module and information sensors.
- There are vacuum losses in the intake manifold. Check the condition of the gasket and vacuum hoses. Replace defective components.
- There is an increased consumption of engine oil as a result of severe wear of the internal components of the engine. Rebuild the power unit.
ABS warning lamp
- The contact connections of the wheel sensors are oxidized, or foreign particles are stuck between the teeth of the signal rotors. Check and make any necessary corrections.
- There are leaks in the GTS. Inspect the cylinder, replace the failed cuffs and gaskets.
- The ABS control module, hydraulic pump, or control valves are malfunctioning. Check the condition of the components, make any necessary corrections/replace defective parts.
- There is a malfunction in the wheel sensors/ABS control module circuit. Carefully inspect the wiring, eliminate the identified defects.
Brake warning lamp
- The hydraulic fluid level in the GTZ reservoir has dropped. Check the hydraulic path of the brake system for signs of leaks, eliminate the identified problems, add the required amount of fluid of the required grade to the reservoir.
- Friction linings of brake pads/boots are excessively worn. Check and replace failed components.
Attention! The replacement of brake pads / shoes is always carried out as a set for both wheels of the respective axle!
- There is a defect in the control lamp signal sensor circuit. Check, make the necessary corrections, replace failed components.
Oil pressure warning lamp
Operating the vehicle with reduced oil pressure is fraught with serious internal engine damage associated with costly repairs!
One of the signs of an unacceptable decrease in oil pressure is an increase in detonation during engine operation.
- If this warning lamp comes on, stop the engine immediately and check the engine oil level and the condition of the oil filter. If necessary, add an appropriate amount of oil from a canister that must be kept in the vehicle and refilled at every oil change.
- Damaged wiring of the sensor-switch of the oil pressure control lamp. With the ignition on (do not start the engine) disconnect the wiring from the sensor-switch - the control lamp should not burn, otherwise check the wiring for signs of a short circuit to ground. Make sure the integrity of the insulation along the entire length of the wires, replace the defective circuit elements.
- The patency of the mesh filter of the oil intake is broken. Remove the oil pan and clean the filter.
- Serviceability of functioning of the gauge-switch of a control lamp of pressure of oil is broken. Install a known-good sensor to test.
- The full-flow oil filter is blocked or there are oil leaks. Replace filter.
Control lamp of a cocking of a parking brake
- Parking brake lever not released. Remember to release the parking brake before driving off.
- The installation position of the sensor-switch of the control lamp is violated, or there is a short circuit in the circuit of its electrical wiring. Check and fix the identified problems.
- The sensor-switch of a control lamp is faulty. Check, replace.
Pilot lamp (s) starts flashing while driving
Charge control lamp
- Faulty alternator or voltage regulator. Check and replace failed components.
- There is a short circuit in the corresponding lamp wiring circuit. Check and make any necessary corrections.
MIL warning lamp («Check engine»)
- The time has come for the next maintenance of the engine, or the settings of the latter are violated. Carry out maintenance, check the settings, evaluate the condition of the spark plugs and air filter, check the level and condition of the engine oil. Make the necessary adjustments and replacements.
- There is an intermittent re-leaning of the air-fuel mixture as a result of approaching the end of the fuel supply in the tank. Fill the car with fuel, reset the lamp.
- The quality of the contact connections in the injection / engine control circuit is broken. Check the condition of the wiring and connectors of the control module and information sensors.
- There are vacuum losses in the intake manifold. Check the condition of the gasket and vacuum hoses. Replace defective components.
- The electrical wiring of the control lamp circuit is damaged. Check the wiring for short circuits, fix any problems found.
ABS warning lamp
- The contact connections of the wheel sensors are oxidized, or foreign particles are stuck between the teeth of the signal rotors. Check and make any necessary corrections.
- There are leaks in the GTS. Inspect the cylinder, replace the failed cuffs and gaskets.
- The ABS control module, hydraulic pump, or control valves are malfunctioning. Check the condition of the components, make any necessary corrections/replace defective parts.
- There is a malfunction in the wheel sensors/ABS control module circuit. Carefully inspect the wiring, eliminate the identified defects.
Brake warning lamp
- The hydraulic fluid level in the GTZ reservoir has dropped. Check the hydraulic path of the brake system for signs of leaks, eliminate the identified problems, add the required amount of fluid of the required grade to the reservoir.
- Friction linings of brake pads/boots are excessively worn. Check and replace failed components.
Attention! The replacement of brake pads / shoes is always carried out as a set for both wheels of the respective axle!
- There is a defect in the control lamp signal sensor circuit. Check, make the necessary corrections, replace failed components.
Oil pressure warning lamp
Attention! Operating a vehicle with reduced oil pressure can result in serious internal engine damage resulting in costly repairs.
One of the signs of an unacceptable decrease in oil pressure is an increase in detonation during engine operation.
- If this warning lamp comes on, stop the engine immediately and check the engine oil level and the condition of the oil filter. If necessary, add an appropriate amount of oil from a canister that must be kept in the vehicle and refilled at every oil change.
- Damaged wiring of the sensor-switch of the oil pressure control lamp. With the ignition on (do not start the engine) disconnect the wiring from the sensor-switch - the control lamp should not burn, otherwise check the wiring for signs of a short circuit to ground. Make sure the integrity of the insulation along the entire length of the wires, replace the defective circuit elements.
- The patency of the mesh filter of the oil intake is broken. Remove the oil pan and clean the filter.
- Serviceability of functioning of the gauge-switch of a control lamp of pressure of oil is broken. Install a known-good sensor to test.
Control lamp of a cocking of a parking brake
- Parking brake lever not released. Remember to release the parking brake before driving off.
- The installation position of the sensor-switch of the control lamp is violated, or there is a short circuit in the circuit of its electrical wiring. Check and fix the identified problems.
- The sensor-switch of a control lamp is faulty. Check, replace.
Pilot lamp (s) does not light up when the ignition is turned on without starting the engine
- Faulty lamp - check by substituting a known good one.
- There is a break in the chain. Check the condition of the relevant electrical wiring.
- The corresponding sensor-switch is faulty, or there is a defect in its electrical wiring circuit. Check, correct the identified problems, replace the defective components.
Direction indicators alarm
Warning lights come on but stay on
- Breaker defective. Replace the failed unit.
There is a two-way failure of signal lights
- The fuse has blown. Check, replace.
- The breaker is out of order - check by substituting a known-good unit.
- There is a fault in the wiring circuit. Check and fix the identified problems.
There is a unilateral failure of signal lights
- Lamps burned out. Check and replace failed lamps.
- The quality of the grounding of the assemblies of the corresponding lights is broken. Check, fix break.
Only one of the signal lights does not turn on
- The lamp has burned out. Check, replace.
- The contact surfaces of the base/cartridge are oxidized. Check and clean the terminals.
- The quality of the grounding of the corresponding lamp socket is broken. Check, fix break.
Beacon flashing frequency greatly reduced
- Too powerful lamps installed. Replace lamps.
The frequency of flashing beacons has been greatly increased
- Insufficient lamps installed. Replace lamps.
- Wrong type of breaker installed. Replace breaker.
Serviceability of functioning of a control lamp of the alarm system is broken
- Corresponding external signal lights are faulty. Check, if necessary, replace the control lamp.
- Alarm switch defective. Check and replace if necessary.
Serviceability of functioning of one of control lamps of indexes of turns is broken
- The lamp has burned out. Check, replace.
- Faulty circuit breaker - check by substituting a known good unit, replace if necessary.
Klaxon
No sound signal
- The corresponding fuse has blown. Check and replace if necessary.
- The serviceability of the power supply to the horn is broken, or there is a break in the ground loop. Check. If power is supplied properly, replace the horn. If a failure is detected, check the condition of the relevant electrical wiring.
Changed the tone of the horn
- On models with one horn, replace the latter.
- On models with a 2-horn horn, check the second horn for proper operation. Alternately disconnecting the electrical wiring from the horns, check the proper functioning of each of them separately. Replace the failed component.
- Check the correct installation of the horn (ov), - the horns must be installed with the socket down. Make sure that no foreign objects get inside the horn.
Windscreen wipers
Windshield wipers not working
- The fuse has blown. Check, replace.
- Control switch defective. Check, correct the identified problems, if necessary, replace the switch.
- The quality of the contact connections in the wiper electric drive circuit is broken. Check, clean the terminals, replace the failed elements.
- The grounding quality of the control switch or drive motor is broken. Check and repair any breaks found.
The drive motor overheats, turning on the wipers blows the fuse
- There is internal damage to the motor. Make a replacement.
- Jammed or deformed wiper arm drive rods. Check, make the necessary corrections, replace failed components.
The functioning of one or both wiper arms is disturbed during the correct operation of the drive electric motor
- Loose fasteners of the corresponding drive rod. Check, tighten fasteners.
- Loose fastening of the lever on the axis of the drive. Tighten the nut, if necessary, replace the corresponding drive arm/axle assembly.
When turned off, the brushes do not return to the parking position
- As a result of a malfunction of the control switch, the procedure for disconnecting power from the drive motor is violated. Check and fix the identified problems.
- There is a fault in the drive motor parking circuit circuit. Replace electric motor. Before installing the levers, run the system in order to find out the correct parking position of the wipers. After completing the installation, turn on the wipers at maximum speed and make sure that the brushes in their extreme positions do not hit the lining of the window opening.
Diagnostics of failures of a combination of devices
The functioning of the speedometer is completely broken
- Drive cable not properly connected to meter assembly or drive gear. Check and make any necessary corrections.
- The drive cable is broken or the lugs that secure it to the meter/pinion assembly are rounded off. Check and replace cable if necessary.
- Worn speedometer drive gear. Check and replace if necessary.
- The meter is defective - check by substituting a known-good assembly. Replace if necessary.
There are fluctuations of the meter needle when moving at a constant speed
- The correct cable laying is violated, there are kinks or twists. Check, make the necessary corrections, if there are signs of damage to the sheath, replace the cable.
- The cable assembly needs lubrication. Remove cable and inspect for damage (replace if necessary), lubricate and reinstall.
There are intermittent malfunctions of the speedometer
- The completeness of the cable connection and the reliability of its fixation in the clamps are violated. Check and make any necessary corrections.
- worn out (rounded) cable ends. Check and replace cable assembly if necessary.
Electrical speedometer
The functioning of the speedometer is completely broken
- Faulty inductive speed sensor output (VSS). Replace sensor.
- Damaged wiring in the circuit between the VSS and the speedometer. Inspect the wiring, evaluate the quality of the contact connections, eliminate the identified problems, replace the defective components.
- Damaged meter, check by substituting a known-good assembly. Replace if necessary.
There are intermittent malfunctions of the speedometer
- The quality of the contact connections in the section of the circuit between the VSS and the speedometer is broken. Check, make necessary corrections, replace defective components.
- Faulty inductive derailment of the speed sensor (VSS). Replace sensor.
Fuel gauges and engine temperature gauges
The functioning of the meter is completely broken
- The corresponding fuse has blown. Check, replace.
- There is an open circuit in the wiring of the corresponding meter. Check and fix the identified problems.
- The corresponding sensor is defective. Check, replace.
- The adequacy of the installation of the meter or its sensor is violated. Check and make appropriate corrections.
The stability of the meter readings is broken
- The quality of the contact connections of the corresponding electrical circuit is broken. Check and fix the identified problems.
- Meter defective. Make a replacement.
The meter continuously captures the maximum reading
- There is a short to ground in the associated meter wiring circuit.
- Meter defective. Make a replacement.
- The meter grounding is broken. Check, fix break.
- The adequacy of the installation of the meter or its sensor is violated. Check and make appropriate corrections.