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

GF07.04-P-6040V Coolant Temperature Sensor Component Description







Location
The coolant temperature sensor is located at the rear in the left cylinder head.

Task
Detects the coolant temperature and supplies a voltage signal to the ME control unit.

Function
The NTC resistor integrated in the coolant temperature sensor, alters its electrical resistance in line with the coolant temperature. NTC is the abbreviation for " Negative Temperature Coefficient", which means electrical resistance falls as the temperature increases (hot conductor).







Body
Metal casing with an integrated, highly responsive NTC resistor and a 2-pole, slanted plug connection. It is inserted into a bore hole and sealed with an O-ring. Fixing via a bracket.

The rapidly responsive NTC temperature sensor is supplied with 5 V by the ME control unit via a series resistor (1470 ohms ± 1 %). Following a short-circuit to battery voltage or 5 V (without a series resistor), the temperature sensor coolant is defective.

The signal is plausible between 0.1 V to 4.93 V, otherwise a fault is identified and a substitute value taken by the ME control unit from a stored temperature model.