Coolant Temperature, Engine

Coolant-temperature Sensor

The coolant-temperature sensor is screwed into the cylinder head and registers the temperature of the coolant by means of its variable resistor (NTC = negative temperature coefficient).

Among other things, the coolant temperature serves as a measured variable for the following functions:
- Start volume calculation
- Injection volume calculation
- Nominal idle speed

In the event of the coolant-temperature sensor failing, a fault code is entered in the DME control module and a substitute value is calculated from the value of the intake air temperature sensor with the aid of a temperature model.