Engine - Coolant Temperature Sensor/Switch: Description and Operation

Component Locations:

The coolant temperature sensor which is located at the rear of the cylinder head, measures engine coolant temperature. The information provided by the coolant temperature sensor is used by the CIS-E control module to calculate air/fuel mixture and idle speed correction. The same information is also used by the EZL control module for calculating timing correction.

Fig. 39 Coolant Temperature Sensor:

Actually there are two independent temperature sensors combined in one housing. One sensor circuit is for the EZL ignition system and one sensor circuit is for the CIS-E fuel injection system.

Temperature Sensor Table:

Both sensors are the negative temperature coefficient (NTC) type (resistance decreases as coolant temperature increases). The sensor has two ground connections, engine ground and CIS-E control module ground.
Since both circuits of the sensor have the same resistance curves, the sensor connector can be installed in either orientation without affecting the operation of the circuit.