Engine - Coolant Temperature Sensor/Switch: Description and Operation
Fig. 39 Coolant Temperature Sensor:
The coolant temperature sensor which is located on the intake manifold near the air flow sensor, measures engine coolant temperature. The information provided by the coolant temperature sensor is used by the CIS-E control unit to calculate air/fuel mixture and idle speed correction. The same information is also used by the EZL control unit for calculating timing correction.
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 unit 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.