Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection

TROUBLESHOOTING PROCEDURES

Circuit Diagram:

CIRCUIT DIAGRAM







HARNESS INSPECTION PROCEDURES


SENSOR INSPECTION
Resistance Test
1. Remove the engine coolant temperature sensor from the intake manifold.




2. With temperature sensing portion of engine coolant temperature sensor immersed in hot water, check resistance.




3. If the resistance deviates from the standard value greatly, replace the sensor.




Voltage Test


TROUBLESHOOTING HINTS
It the fast idle speed is not high enough or the engine gives off dark smoke during the engine warm-up operation, it might be caused by the engine coolant temperature sensor.