Envoy 2WD V6-4.3L VIN W (1998)
Ambient Temperature Sensor / Switch HVAC: Description and Operation
The ambient air temperature sensor is a temperature-sensitive resistor.
The resistance of the ambient air temperature sensor varies inversely with the outside air temperature. As the outside air temperature increases, the
resistance decreases. As the outside air temperature decreases, the resistance increases.
The heater and A/C control module monitors the outside temperature signal and uses this information in order to help determine command signals. The
sensor will not update when the vehicle is traveling less than 5 mph.