GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Turn On the ignition with the engine OFF.
  2. Ensure the dome lamp override switch is in the OFF position.
  3. Connect a scan tool.
  4. Using the scan tool, test for any DTCs in the body control module (BCM).

Does the scan tool show any DTCs?

--

Go to Diagnostic System Check - Body Control System in Body Control System

Go to Step 2

2

  1. Close all of the doors.
  2. Turn the dome lamp override switch to the ON position.
  3. Using the scan tool, read the dome lamp switch status.

Does the scan tool show the switch status ON?

--

Go to Step 3

Go to Step 4

3

Replace the BCM. Refer to Body Control Module Replacement in Body Control Systems.

Is the replacement complete?

--

System OK

--

4

  1. Disconnect the headlamp and panel dimmer switch.
  2. Connect a fused jumper wire from terminal E to terminal G.
  3. Using the scan tool, read the dome lamp switch status.

Does the scan tool show the switch status ON?

--

Go to Step 5

Go to Step 6

5

Replace the headlamp and panel dimmer switch. Refer to Headlamp Switch Replacement .

Is the replacement complete?

--

System OK

--

6

  1. Connect a fused jumper wire from terminal G of the headlamp and panel dimmer switch to ground.
  2. Using the scan tool, read the dome lamp switch status.

Does the scan tool show the switch status ON?

--

Go to Step 7

Go to Step 8

7

Locate and repair the open in CKT 1850 (BLK) between the headlamp and panel dimmer switch and ground.

Is the repair complete?

--

System OK

--

8

Locate and repair the open in CKT 1495 (DK BLU/WHT) between the BCM and the headlamp and panel dimmer switch.

If no open is found, replace the BCM. Refer to Body Control Module Replacement in Body Controls Systems.

Is the repair complete?

--

System OK

--