Circuit/System Testing
WARNING: This page is about a different car, the 2010 Cadillac SRX. However, it is still accessible from the selected car via links, so may be relevant.
- Disconnect the harness connector at the appropriate courtesy lamp.
- Ignition OFF, scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5.0 Ω between the ground circuit terminal listed below and ground:
- Instrument Panel Courtesy Lamp - terminal 2
- Door Courtesy Lamp - terminal 2
- Overhead Console Courtesy/Reading Lamp - terminal 2
- Rear Courtesy/Reading Lamp - terminal B
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Connect a test lamp between the control circuit terminal listed below and ground:
- Instrument Panel Courtesy Lamp - terminal 1
- Door Courtesy Lamp - terminal 1
- Overhead Console Courtesy/Reading Lamp - terminal 3
- Rear Courtesy/Reading Lamp - terminal C
- Command the Courtesy Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF 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 K9 BCM.
- If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
- If all circuits test normal, replace the courtesy lamp.