Temperature sensor check K-Jetronic, KE-Motronic

The temperature sensor is located on the left side of the cylinder head and measures the temperature of the coolant. A faulty temperature sensor causes cold starting problems and difficulty idling. In the presence of the KE-Motronic system, in the event of a temperature sensor failure, the control unit switches to work according to the time program. In this case, as an alternative to the actual temperature values, the following values are accepted: when starting the engine - 0°С and +60°С for all other ranges of engine operation. The memory device of codes of malfunctions fixes existence of malfunction.

When installed, the temperature sensor can be tested at various engine temperatures.



green-red wire (K-Jetronic) or, respectively, a plug with purple-black and brown-white wire (KE-Motronic) and using an ohmmeter, measure the resistance between the contact and the housing.

K-Jetronic

Compare the resistance values measured at different temperatures with the values given in the diagram. To do this, the engine warms up and the measurements are repeated at different temperatures. In this case, take the temperature indicated by the coolant temperature gauge as the engine temperature.


KE-Motronic: The diagram above only applies to engines with the K-Jetronic system. Prescribed resistance values at certain temperatures for an engine with KE-Motronic:



If the measured values do not match the prescribed values, unscrew the temperature sensor and replace it.