Engine Coolant Temperature Sensor

GENERAL INFORMATION

The sensor is installed at the rear of the cylinder head (flywheel side).

The sensor is a thermistor supplied with stabilized voltage and is connected in the gauge circuit. Inspection

PROCEDURE

1. As the coolant heats up, the current through the sensor increases and the gauge needle should move to the right. Replace a faulty sensor.

2. If the temperature reading is incorrect, check the operation of the other gauges.

3. If none of the gauges work, check the power supply circuit of the instrument cluster.

4. If all gauges give incorrect readings, replace the voltage stabilizer (mounted on the instrument cluster circuit board).

5. If only the temperature gauge is faulty, proceed as follows.

6. If the reading is too low, disconnect the wire from the sensor and ground it.

7. If the needle moves with the ignition on, the sensor is faulty.

8. If the reading does not change, remove the instrument cluster (see subsection 14.9) and check the wiring from the sensor to the gauge and the gauge power supply.

9. If power is supplied and the wiring is good, the gauge is faulty.

10. If the reading is too high, disconnect the wire from the sensor.

11. If the needle moves to the left side of the scale on a cold engine, the sensor is faulty.

12. If the reading does not change, check the rest of the circuit.

Removal On some vehicles, it may be necessary to disconnect or move hoses and wiring aside to access the sensor.

PROCEDURE

1. Disconnect the battery ground cable.

2. On a cold engine, drain some of the coolant to the level of the thermoswitch.

3. Disconnect the thermoswitch connector.

4. Carefully unscrew the thermoswitch and remove the seal (if equipped).

Installation

PROCEDURE

1. Clean the thermoswitch and apply sealant to the threads.

2. Replace the seal (if equipped).

3. Install in the reverse order.