Outside Temperature Sensor
The function of the outside temperature sensor is to detect the vehicle's ambient temperature. The ambient temperature is required so that the Engine Control Module (ECM) can regulate, among other things:
- Engine cooling fan.
- the air conditioning (A/C) compressor's displacement.
The ambient temperature is also used as a substitute value in the event of a fault in certain components or functions and to control certain diagnostic functions.
The temperature sensor is a resistor with a negative temperature coefficient, so called NTC type. It is supplied with electric power from the control module.
Depending on temperature, the resistance changes in the sensor; low temperature gives high resistance, high temperature gives low resistance.
The control module monitors the voltage in the circuit and can thus determine the temperature.
The Engine Control Module (ECM) can diagnose the outdoor temperature sensor.
The outside temperature sensor is positioned in the left door mirror.