Air Temperature Sensors
WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The air temperature sensors are a 2-wire negative temperature co-efficient thermistor. The vehicle uses the following air temperature sensors:
- Ambient air temperature sensor
- Inside air temperature sensor assembly
- Upper air temperature sensor
- Lower air temperature sensor
- A/C evaporator temperature sensor
A signal and low reference circuit enables the sensor to operate. As the air temperature surrounding the sensor increases, the sensor resistance decreases. The sensor signal voltage decreases as the resistance decreases. The sensor operates within a temperature range between -40 to +101°C (-40 to +215°F). The sensor signal varies between 0-5 volts. The input of the duct air temperature sensors are different from the ambient and inside air temperature sensors. The HVAC control module converts the signal to a range between 0-255 counts. As the air temperature increases the count value will decrease.