Circuit/System Testing
WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
If the evaporator air temperature sensor has an out of range condition caused by a short to voltage, short to ground, or an open/high resistance, the scan tool will display the same value: 11°C (51°F).
- Ignition OFF, disconnect the harness connector at the evaporator air temperature sensor.
- Ignition OFF, test for less than 10 ohms between the low reference circuit terminal 2 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, test for 4.8-5.2 volts between the signal circuit terminal 1 and low reference circuit terminal 2.
- If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the HVAC control module.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HVAC control module.
- If all circuits test normal, test or replace the evaporator air temperature sensor.