The temperature sensor is screwed into the cylinder head. A varistor (NTC = Negative Temperature Coefficient) serves as the measure for the coolant temperature. A resistor of this kind is also used to sense the radiator outlet temperature.
The coolant temperature sensor, S54 engine, also serves as a measured variable for the following functions:
In the event of the sensor failing, a fault code is entered in the DME control unit and a substitute value is calculated from the value of the intake air temperature sensor with the aid of a temperature model.