Engine - Coolant Temperature Sensor/Switch: Description and Operation

Coolant Temperature Sensor (CIS):

PURPOSE
The PCME utilizes temperature sensor information in its calculations for outputs such as air/fuel ratio control and emission devices.

LOCATION
Right end of engine near oil filler.

OPERATION
The sensor is a thermistor device whose resistance varies with changes in coolant temperature. The PCME sends a reference voltage to the sensor and measures changes in resistance as engine temperature fluctuates.

COOLANT TEMP. RESISTANCE (K OHMS)

20°C (68°F) 2.2 - 2.7
60°C (140°F) 0.50 - 0.65
80°C (176°F) 0.29 - 0.35
91°C (196°F) 0.226 - 0.241
108°C (226°F) 0.145 - 0.153
110°C (230°F) 0.137 - 0.146