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Circuit/System Testing

WARNING: This page is about a different car, the 2008 Pontiac G5 and 2008 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at the ambient light sensor.
  2. Ignition OFF, scan tool OFF, doors CLOSED, test for less than 10 ohms between the low reference circuit terminal B 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, verify the scan tool Ambient Light Sensor parameter is greater than 4.65 volts.
    • If less than the specified range, test the signal circuit terminal A for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  4. Install a 3 A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool Ambient Light Sensor parameter is less than 0.196 volts.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM.
  5. If all circuits test normal, replace the ambient light sensor.
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