Circuit/System Testing
WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
I/P Dimmer Switch Malfunction
- Ignition OFF, disconnect the harness connector at the I/P dimmer switch.
- Ignition OFF, verify that a test lamp illuminates between B+ and the ground circuit terminal 4.
- If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
- Ignition ON, verify the scan tool Dimming Control Signal parameter is less than 0.0 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.
- Ignition ON, test for B+ between the voltage reference circuit terminal 12 and ground.
- If less than the specified value, test the voltage reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
- Install a 3A fused jumper wire between the signal circuit terminal 13 and the voltage reference circuit terminal 12. Verify the scan tool Dimming Control Signal parameter is greater than 2.5 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 I/P dimmer switch.
I/P Dimming Control Malfunction
- Ignition OFF, disconnect the X4 harness connector at the BCM.
- Ignition ON, verify that a test lamp illuminates between the BCM VB4 fuse B+ circuit terminal 4 and ground.
- If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
- If all circuit tests normal, replace the BCM.