Circuit/System Testing
WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. 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 1.0 ohm of resistance between the appropriate ground circuit terminal and ground.
- Duct temperature sensor ground circuit terminal A
- Ambient temperature sensor ground circuit terminal B
- Inside air temperature sensor ground circuit terminal C
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Ignition ON, verify the appropriate scan tool temperature sensor parameter is greater than 250 counts.
- If less than the specified range, test the appropriate signal circuit terminal for a short to ground. If the circuit tests normal, replace the HVAC control module.
- Duct temperature sensor signal circuit terminal B
- Ambient temperature sensor signal circuit terminal A
- Inside air temperature sensor signal circuit terminal B
- Install a 3A fused jumper wire between the appropriate signal circuit terminal and ground. Verify the appropriate scan tool temperature sensor parameter is less than 5 counts.
- Duct temperature sensor signal circuit terminal B
- Ambient temperature sensor signal circuit terminal A
- Inside air temperature sensor signal circuit terminal B
- If greater 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 temperature sensor.