Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Air Temperature Sensors
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
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 °C (-40 °F) to 101 °C (215 °F). The sensor signal varies between 0-5 volts.
The input of the duct sensor temperature is different from the ambient and inside 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.
If the HVAC control module detects a malfunctioning sensor, then the control module software will use a defaulted air temperature value. The default action ensures that the HVAC system can adjust the inside air temperature near the desired temperature until the condition is corrected.
The Driver Information Center (DIC) displays the ambient air temperature value that it receives from the HVAC control module through a class 2 message. The scan tool has the ability to update the displayed ambient air temperature. The ambient air temperature value is displayed or updated under the following conditions:
| Condition | Display |
|---|---|
| At start up with the engine off more than 3 hours | Displays real-time temperature |
| At start up with the engine off less than 3 hours | Displays last stores temperature |
| Vehicle moving above 26 km/h (16 mph) for 1.5 minutes | Displays real-time temperature |
| Vehicle moving above 72 km/h (45 mph) for 1 minute | Displays real-time temperature |
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.