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Circuit/System Testing

WARNING: This page is about a different car, the 2012 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.

I/P Dimmer Switch Malfunction

  1. Ignition OFF, disconnect the harness connector at the I/P Dimmer switch.
  2. Ignition OFF, exterior lamps OFF, scan tool OFF, test for less than 10 ohms between the low reference circuit terminal 1 and ground.
    • If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  3. Ignition ON, park lamps ON, test for B+ between the signal circuit terminal 3 and ground.
    • 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.
  4. Install a 3A fused jumper wire between the signal circuit terminal 3 and the low reference circuit terminal 1. Verify the scan tool IP Dimmer Switch parameter is less than B+.
    • If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM.
  5. If all circuits test normal, test or replace the I/P dimmer switch.

Interior Backlighting Malfunction

  1. Ignition OFF, disconnect the harness connector at the component with the inoperative backlighting.
  2. Ignition OFF, exterior lamps OFF, test for less than 5 ohms between the ground circuit and ground.
    • If greater than the specified value, test the ground circuit for an open/high resistance.
  3. Connect a test lamp between the control circuit and ground.
  4. Park lamps ON, command the Interior Dimming the Increase and Decrease with a scan tool. The test lamp brightness should increase and decrease when changing between the commanded states.
    • If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
    • If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
  5. If all circuits test normal, test or replace the component with the inoperative incandescent backlighting.
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