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. See Fig 1 .

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.

Fig 1: Engine Coolant Temperature Sensor Monitoring & Enabling Conditions

Courtesy of LAND ROVER NORTH AMERICA, INC.