Circuit/System Testing
WARNING: This page is about a different car, the 2016 GMC Acadia, 2016 Chevrolet Traverse, and 2016 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT:
If the ambient air temperature sensor is in temperatures below 2°C (35°F) the compressor clutch will be disabled until the vehicle is driven above 45 mph (72 km/h), the ignition is OFF for more than 3 hours or an instant OAT update is performed.
IMPORTANT:
An instant OAT update must be performed by pressing the A/C and Recirc buttons at the same time before and after the system has been serviced to update the filtered ambient air temperature sensor circuit and convert the A/C permission from withheld to granted.
- Ignition OFF, disconnect the harness connector at the ambient air temp sensor.
- Ignition OFF, test for less than 10 ohms of resistance between the low reference circuit terminal B and ground.
- 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 the scan tool Ambient Air Temp Sensor parameter is less than -35°C (-39°F).
- If greater than the specified range, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the HVAC control module.
- Install a 3 A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool Ambient Air Temp Sensor Raw parameter is greater than 85°C (185°F).
- 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 ambient air temp sensor.
IMPORTANT:
An instant OAT update must be performed to grant A/C permission after testing or replacing the ambient air temperature sensor.