H1 V8-6.5L DSL (1998)
Coolant Temperature Sensor/Switch (For Computer): Description and Operation
Figure 3-11: Coolant Temperature Sensor Circuit
Engine Coolant Temperature Sensor Test
The coolant temperature sensor is a thermistor that provides a temperature signal to the PCM (Figure 3-11). The signal is in the form of a voltage that
changes according to sensor resistance. At low temperatures, resistance and voltage are both high. As temperature increases, resistance and voltage both
decrease.
A sensor fault will cause the check engine light to illuminate and the torque converter clutch to apply early. If the sensor fails in a cold mode, it can
produce overrich operation and rough idle.
