Coolant Temperature Sensor/Switch (For Computer): Description and Operation

Engine Coolant Temperature Sensor

Description

The Engine Coolant Temperature Interface consists of 1 analogue voltage input signal for Engine Coolant Temperature and a reference ground. Note that the sensor itself is a dual element sensor with one element used by the ECM and the second element used by the Instrument Pack.

There are four diagnostic checks of the Engine Coolant Temperature sensor, a fault is detected if:-
1. If the resistance of the sensor is less than 0.05 K Ohms.
2. If the resistance of the sensor is greater than 75.8 K Ohms.
3. The time taken to reach the closed loop fuelling enable temperature exceeds a threshold.
4. The difference between the Engine Coolant Temperature Model and the temperature indicated by the Engine Coolant Temperature sensor is greater than a threshold.