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 outside moisture sensor.
- Test for less than 5.0 ohms between the ground circuit terminal 3 and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Ignition ON, verify that a test lamp illuminates between ignition circuit terminal 4 and ground.
- If the test does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
- Ignition OFF, connect the harness connector at the outside moisture sensor.
- Disconnect the X4 harness connector at the BCM.
- Ignition ON, test for 8-10 volts between the signal circuit terminal 18 and ground.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the outside moisture sensor.
- If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the outside moisture sensor.
- Ignition ON, test for 4-8.5 volts between the signal circuit terminal 14 and ground.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the outside moisture sensor.
- If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the outside moisture sensor.
- If all circuits test normal, replace the BCM.