The temperature sensor is screwed into the cylinder head. A varistor (NTC = Negative Temperature Coefficient) serves as the measure for the coolant temperature.
Among other things, the coolant temperature serves as a measurement variable for following functions:
In the event of the engine coolant temperature 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.
The housing of the coolant temperature sensor contains two sensors (double temperature sensor). The one sensor sends the signal to the DME control unit while the other sensor is connected to the instrument cluster.