GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Turn the ignition to the ON position.
  2. Ensure the dome lamp override switch is in the OFF position.
  3. Connect a scan tool.
  4. Using the scan tool, check 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 the doors.
  2. Using the scan tool, read the dome lamp switch status.

Does the scan tool show the switch status as ON?

--

Go to Step 3

Go to Step 6

3

  1. Disconnect the headlamp and panel dimmer switch.
  2. Using the scan tool, read the dome lamp switch status.

Does the scan tool show the switch status as ON?

--

Go to Step 5

Go to Step 4

4

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

Is the repair complete?

--

System OK

--

5

Locate and repair CKT 1495 (DK BLU/WHT) for a short to ground.

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

Is the repair complete?

--

System OK

--

6

Using the scan tool, read the driver door jamb switch and the door handle switch status.

Does the scan tool show INACTIVE?

--

Go to Step 9

Go to Step 7

7

  1. Disconnect the LH or the mini wedge, (door jamb switch).
  2. Using the scan tool, read the driver door jamb switch and the door handle switch status.

Does the scan tool show INACTIVE?

--

Go to Step 11

Go to Step 8

8

Locate and repair the short to ground in CKT 126 (TAN)/CKT 54 (ORN) for the Base or CKT models or CKT 394 (LT GRN/BLK) for the Uplevel models.

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

Is the repair complete?

--

System OK

--

9

Remove the courtesy lamp relay.

Do the courtesy lamps turn off?

--

Go to Step 12

Go to Step 10

10

Locate and repair CKT 156 (WHT) for a short to ground.

Is the repair complete?

--

System OK

--

11

Replace the LH or the RH mini wedge (door jamb switch). Refer to Front Side Door Lock Actuator Replacement in Doors.

Is the repair complete?

--

System OK

--

12

Replace the courtesy lamp relay.

Is the repair complete?

--

System OK

--