Circuit/System Testing
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector at the ambient light sensor.
- Ignition OFF, scan tool OFF, doors CLOSED, test for less than 5.0 ohms between the appropriate ground circuit terminal listed below and ground.
- Terminal B - with C67/C42
- Terminal C - with CJ2
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Ignition ON, verify the scan tool Ambient Light Sensor parameter is greater than 4.5 volts.
- If less than the specified range, test the appropriate signal circuit terminal listed below for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
- Terminal A - with C67/C42
- Terminal D - with CJ2
- If less than the specified range, test the appropriate signal circuit terminal listed below for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
- Install a 3A fused jumper wire between the appropriate signal circuit terminal listed below and ground. Verify the scan tool Ambient Light Sensor parameter is less than 0.196 volts.
- Terminal A - with C67/C42
- Terminal D - with CJ2
- 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 BCM
- If all circuits test normal, replace the ambient light sensor.