The sensor is a thermistor powered by a stabilized voltage and is included in the indicator circuit.
Examination
1. As the liquid heats up, the current through the sensor increases and the pointer should move to the right. A faulty sensor should be replaced.
2. If the temperature readings are incorrect, check the operation of the other devices.
3. If the instruments do not work, check the instrument panel power circuit.
4. If all devices give erroneous readings, replace the voltage stabilizer (mounted on the instrument panel printed circuit board).
5. If only the temperature gauge is faulty, proceed as follows.
6. If the readings are low, disconnect the wire from the sensor and touch the ground.
7. If the needle moves when the ignition is on, the sensor is faulty.
8. If the readings do not change, remove the instrument panel (see subsection 14.9) and check the wiring from the sensor to the indicator and the power supply to the indicator.
9. If power is supplied and the wiring is good, then the indicator is faulty.
10. If the readings are too high, disconnect the wire from the sensor.
11. If the needle moves to the left side of the scale when the engine is cold, the sensor is faulty.
12. If the readings do not change, then check the rest of the circuit.
Removal
On some vehicles, you may need to disconnect or move aside hoses and wiring to access the sensor.
1. Disconnect the battery from ground.
2. When the engine has cooled down, drain some of the fluid to the level of the thermal switch.
3. Disconnect the thermal switch connector.
4. Carefully unscrew the thermal switch and remove the seal (if provided).
Installation
1. Clean the thermal switch and apply thread sealant to the threads.
2. Replace the seal (if provided).
3. Then assembly is carried out in reverse order.