GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Interior Lights Schematics

1

Did you perform the Lighting Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Verify the fault is present.

Does the system operate normally?

Go to Testing for Electrical Intermittents in Wiring Systems

Go to Step 3

3

  1. Ensure the dome lamp override switch is in the OFF position.
  2. Close all the doors.
  3. With the scan tool, read the dome lamp switch status.

Does the scan tool display the switch status as ON?

Go to Step 4

Go to Step 5

4

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

Does the scan tool display the switch status as ON?

Go to Step 8

Go to Step 11

5

With the scan tool, read the driver door jamb switch status.

Does the scan tool display INACTIVE?

Go to Step 7

Go to Step 6

6

  1. Disconnect the LH mini wedge, (door jamb switch).
  2. With the scan tool, read the driver door jamb switch status.

Does the scan tool display INACTIVE?

Go to Step 12

Go to Step 9

7

Remove the courtesy lamp relay.

Do the courtesy lamps turn off?

Go to Step 13

Go to Step 10

8

  1. Repair the short to ground in the courtesy lamp switch output circuit. Refer to Wiring Repairs in Wiring Systems.
  2. If no short is found, replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the repair?

Go to Step 14

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9

Repair the door latch switch signal circuit for a short to ground. Refer to Wiring Repairs in Wiring Systems. If no short is found, replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the repair?

Go to Step 13

--

10

Repair the short to ground in the courtesy lamp output circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 14

--

11

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

Did you complete the replacement?

Go to Step 14

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12

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

Did you complete the repair?

Go to Step 14

--

13

Replace the courtesy lamp relay.

Did you complete the repair?

Go to Step 14

--

14

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3