NOTE: A CHT sensor that has already been removed may no longer be used.
The CHT sensor is screwed into the cylinder head and measures the material temperature.
It replaces the familiar ECT sensor.
By measuring the material temperature, engine overheating (e.g. through the loss of coolant) is clearly detected.
At high temperatures, the resolution of the CHT sensor is not high enough to adequately cover the entire temperature range from –40 °C to +214 °C. Therefore the temperature curve is shifted by activating a second resistor in the PCM.
The resistor is activated at a temperature of:
• 85 °C.
The resistor is deactivated at a temperature of:
• 80 °C.