FixVault

Circuit/System Testing

WARNING: This page is about a different car, the 2009 Saturn Outlook, 2009 GMC Acadia, 2009 Chevrolet Traverse, and 2009 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at the headlamp switch.
  2. Ignition ON, test for 12 volts between the dimming reference voltage circuit terminal 15 and ground.
    • If less than the specified range, test the dimming reference voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  3. Verify the scan tool Dimming Control Reference parameter is less than 1 volt.
    • If greater than the specified range, test the signal circuit terminal 13 for a short to voltage. If the circuit tests normal, replace the BCM.
  4. Install a 3A fused jumper wire between the signal circuit terminal 13 and the dimming reference voltage circuit terminal 15. Verify the scan tool Dimming Control Reference parameter is greater than 11 volts.
    • 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 BCM.
  5. If all circuits test normal, test or replace the headlamp switch.