General information
In order to reduce the emission of nitrogen oxides into the atmosphere, part of the exhaust gases is returned to the intake manifold through the EGR valve. This admixture of exhaust gases to the air-fuel mixture leads to a decrease in its combustion temperature.
The system consists of EGR valve, EGR control solenoid valve (only used on some models), EGR valve opening sensor and control module (ECM/PCM). The ECM/PCM is programmed to provide the optimum EGR valve opening for all engine operating conditions. A special information sensor constantly monitors the degree of opening of the EGR valve, issuing appropriate signals to the control module. The ECM/PCM compares the input information with data from other sensors and, if necessary, adjusts the depth of vacuum applied to the EGR valve through the control solenoid valve.
Examination
Models equipped with CVT
1. Start the engine and warm it up to normal operating temperature (cooling fan should turn on).
2. Disconnect the vacuum hose from the EGR valve and connect a vacuum gauge to it.
3. There should be no vacuum, if this condition is met, proceed to the procedures of paragraph 5.
4. If vacuum exists, disconnect the EGR control solenoid connector and recheck for vacuum at the EGR valve.
Note. To find the solenoid valve, walk along the vacuum hose from the EGR valve. If there is no vacuum, drive the vehicle to a workshop for ECM/PCM diagnostics using a special reader (see Checking the condition and replacing the TDC sensor / crankshaft position / piston position in the engine cylinders (TDC/TFR/CYP)). If there is a vacuum, check that the vacuum lines are routed correctly. If the hoses are OK, replace the solenoid valve.
5. If there was no vacuum from the very beginning, connect a hand vacuum pump to the EGR valve and create a vacuum with a depth of 203 mm Hg. Art. - The engine should stop. Also check the ability of the valve to hold vacuum, if this ability is not available, replace the assembly.
6. Check for battery voltage at the EGR control solenoid valve. Disconnect the 2-pin valve connector and connect a voltmeter between the positive terminal of the main harness connector (red wire terminal) and mass. Battery voltage must be present.
7. Connect a vacuum gauge to the EGR valve vacuum hose and start the engine to idle. Using a jumper wire, connect the positive battery terminal to the red wire terminal on the back of the harness side connector. While observing the vacuum gauge, ground the second terminal of the 2-pin connector using the second jumper wire. Depth of rarefaction must increase within one second (solenoid valve operation sound should be heard). If there is no vacuum, replace the EGR solenoid valve assembly.
8. More detailed diagnostics of the system requires the use of a special reader and must be carried out in a car service workshop.
Models with manual transmission
1. Start the engine and warm it up to normal operating temperature (cooling fan should run).
2. Disconnect the EGR valve 6-pin connector and check for battery voltage between the pink and black wire terminals of the main wiring harness. If there is no voltage, check the pink wire between the valve and the ECM/PCM for signs of open or loose connections. Also check the grounding of the black wire. If the wiring is good, the vehicle should be taken to a workshop for a detailed diagnosis of the ECM/PCM.
3. If battery voltage is present, stop the engine. Using a jumper wire, connect the positive battery terminal to the pink wire terminal of the 6-pin EGR valve/opening degree sensor harness connector. Run the engine to idle and use the second jumper wire to ground the connector black wire terminal. The stability of the idle speed should be abruptly disturbed, up to the stop of the engine, otherwise replace the valve/sensor assembly. If there are no changes in the operation of the engine, check the wiring for an open and the reliability of the fastening of the contact connections.
4. More detailed diagnostics of the system requires the use of a special reader and must be carried out in a car service workshop.
Component Replacement
EGR valve
1. Disconnect the electrical wiring from the EGR valve opening sensor. Disconnect the vacuum hose.
2. Give two fixing nuts and remove the EGR valve from the inlet pipeline.
3. Clean mating surfaces of valve and adapter.
4. Replace the gasket and install the EGR valve in its original location. Tighten the fixing nuts firmly.
5. Restore the original wiring connection.
EGR control solenoid valve (only models with CVT)
1. Walking through the vacuum hose from the EGR valve, find the system control solenoid valve. Disconnect the electrical wiring and vacuum hoses, unscrew the fixing screws and remove the valve.
2. Installation is carried out in the reverse order.