Dimmer Switch Circuit Test
WARNING: This page is about a different car, the 2010 Saturn Outlook, 2010 GMC Acadia, 2010 Chevrolet Traverse, and 2010 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector at the headlamp switch.
- Ignition OFF, verify that a test lamp illuminates between the ground circuit terminal 8 and B+.
- If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
- Ignition ON, test for 11.8-12.2 volts between the 12 V reference circuit terminal 15 and ground.
- If greater than the specified range, test the 12 V reference circuit for a short to voltage. If the circuit tests normal, replace the BCM.
- If less than the specified range, test the 12 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
- Ignition ON, verify the scan tool Dimming Control Signal parameter is less than 0.1 volts.
- 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.
- Install a 3 A fused jumper wire between the signal circuit terminal 13 and the voltage reference circuit terminal 15. Verify the scan tool Dimming Control Signal parameter is greater than 11.7 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.
- If all circuits test normal, test or replace the headlamp switch.