Vauxhall Workshop Service and Repair Manuals

Coolant Temperature Sensor, X 18 XE1 and X 20 XEV  

In the X 18 XE1, the coolant temperature sensor is attached to the thermostat housing, and in the X 20 XEV it is installed on the DIS ignition module adapter (coolant flange).   The coolant temperature sensor measures the temperature of the coolant, which corresponds to the engine temperature.   The sensor has a temperature-dependent resistor which protrudes into the coolant circuit and assumes its temperature. The resistor has a negative temperature coefficient (NTC), which means that the resistance sinks as the temperature increases.   The signal from the coolant temperature sensor is required for:     •  the engine cooling module control unit (actuation of radiator fan)   •  the temperature gauge   •  calculation of the injection quantity     I   Coolant temperature sensor (B12)       1  Electric connection   2  Casing   3  NTC resistor     II   Characteristic curve of NTC resistor       Ω   Resistance   ° C   Coolant temperature