Circuit/System Testing

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.

Ignition OFF, disconnect the harness connector at the appropriate temperature sensor.
Ignition OFF, test for less than 10 ohms between the appropriate low reference circuit terminal listed below and ground:
- Inside air temperature sensor terminal D
- Upper/lower air temperature sensor terminal 2
- If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the HVAC control module.
Ignition ON, verify that both the scan tool Inside Air Temp. Sensor or the appropriate Duct Actual parameter is less than -35°C (-39°F).
- If greater than the specified range, test the appropriate signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the HVAC control module.
  - Inside air temperature sensor terminal A
  - Upper/lower air temperature sensor terminal 1
Install a 3A fused jumper wire between the appropriate circuits listed below. Verify the scan tool Inside Air Temp. Sensor or the appropriate Duct Actual parameter is greater than 98°C (208°F).
- Inside air temperature sensor signal circuit terminal A and low reference circuit terminal D
- Upper/lower air temperature sensor signal circuit terminal 1 and low reference circuit terminal 2
- If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
If all circuits test normal, test or replace the appropriate air temperature sensor.