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Circuit/System Testing

WARNING: This page is about a different car, the 2006 Chevrolet Monte Carlo and 2006 Chevrolet Impala. 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 B+ between the signal circuits listed below and ground.
    • Headlamp switch headlamps ON signal terminal 1
    • Park lamp switch ON signal terminal 2
    • Headlamp switch OFF signal terminal 3
    • If less than the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  3. Install a 3A fused jumper wire between the headlamp OFF signal circuit terminal 3 and ground. Verify the scan tool Auto Hdlp. Disable Sw. parameter is Active.
    • If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  4. Install a 3A fused jumper wire between the park lamp ON signal circuit terminal 2 and ground. Verify the scan tool Parklamp Switch parameter is Active.
    • If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  5. Connect a 3A fused jumper wire between the park lamp ON signal circuit terminal 2 and the headlamps ON signal circuit terminal 1 to ground. Verify the scan tool Headlamp Switch parameter is Active.
    • If not the specified value, test the headlamps On signal circuit for a short to voltage or an open/high resistance. If the circuits test normal replace the BCM.
  6. If all circuits test normal, replace the headlamp switch.
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