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Circuit/System Testing

WARNING: This page is about a different car, the 2007 Pontiac Torrent and 2007 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at the dimmer switch.
  2. Ignition OFF, test for less than 1.0 ohm of resistance between the low reference circuit and ground.
    • If greater than 1.0 ohm, 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, verify the scan tool I/P dimmer input is greater than 4.5 volts.
    • If less than 4.5 volts, test the signal circuit for a short to ground. If the circuit tests normal, replace the BCM.
  4. Install a 3-amp fused jumper wire between the signal circuit and the low reference circuit. Verify the scan tool I/P dimmer input is less than .5 volts.
    • If greater than .5 volts, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  5. If all circuits test normal, test or replace the dimmer switch.
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