Examination
1. The ECT sensor is a thermistor (resistor whose resistance changes with temperature). A change in the resistance of the sensor has a direct effect on the amplitude of the signal it produces on the PCM. At the same time, with a DECREASE in temperature, the resistance of the sensor INCREASES, and vice versa. Failure of the ECT sensor leads to the entry of code P0116, P0117 or P0118 into the self-diagnosis system memory block.
2. Checking the correct functioning of the ECT sensor is carried out by measuring its resistance. Locate the sensor and disconnect the wiring from it.
3. Connect an ohmmeter to the two sensor assembly terminals. At a temperature of about 20°C, the device should register a reading in the region of 2500 ÷ 3500 Ohm. Now start the engine and warm it up to normal operating temperature (alternatively, the sensor can be removed and warmed up to the required temperature in a hot bath). The resistance of the sensor should drop, and at a temperature of about 83°C it should be 250÷350 Ohm. If the test described above fails, the ECT sensor must be replaced.
Note. If the engine was running with the sensor disconnected, do not forget to clear the memory of the self-diagnosis system (see Section On-Board Diagnostic System (OBD) - the principle of operation and fault codes).
Replacement
Attention! Wait until the engine has completely cooled down before proceeding with the procedure.
1. Disconnect the negative cable from the battery.
Attention! If the stereo system installed in the car is equipped with a security code, before disconnecting the battery, make sure that you have the correct combination to activate the audio system!
2. Before installing a new sensor, its threaded part should be wrapped with Teflon sealing tape (FUM tape).
3. Wring out a lock uvula, disconnect electroconducting, then carefully turn out the gauge. To minimize coolant loss, try to screw in the replacement sensor as soon as possible.
Attention! Handle the ECT sensor as carefully as possible, as damage to it can have a noticeable effect on the functioning of the power system as a whole.
4. Installation is carried out in the reverse order. Finally, check the coolant level and correct if necessary (see chapter Settings and ongoing maintenance).