Fuel Temperature Sensor: Description and Operation

GF47.50-P-2010IC Component Description For The Fuel Temperature Sensor
- ENGINE 647.961 in MODEL 211
- ENGINE 648.960 in MODEL 220
- ENGINE 648.961 in MODEL 211





Location
19 High-pressure pump
B50 Fuel temperature sensor
Y94 Quantity control valve

The fuel temperature sensor is located on the high pressure pump flange, at the front on the cylinder head.

Task
The temperature sensor detects the temperature of the fuel flowing to the high pressure pump.





Function
1, 2 Connection pins
B50 Fuel temperature sensor

The NTC resistor integrated in the temperature sensor alters its electrical resistance in line with the fuel temperature. The CDI control unit (N3/9) applies a sensor voltage of 5 V and evaluates the signal voltage in accordance with the fuel temperature.

NTC means "Negative Temperature Coefficient", which means: the electrical resistants reduces with increasing temperature (thermistor).

If the fuel temperature is too high, the rail pressure is lowered.

The connection assignment (polarity) of connection pin 1 and 2 is random.