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

Operate the courtesy lamps to verify the fault is present.

Does the system operate normally?

Go to Testing for Electrical Intermittents in Wiring Systems

Go to Step 3

3

Is only one lamp inoperative?

Go to Step 4

Go to Step 6

4

Test the courtesy lamps supply voltage circuit of the inoperative lamp a high resistance, an open, or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 5

5

Test the ground circuit of the inoperative lamp a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 15

6

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

Does the scan tool display the switch status as OFF?

Go to Step 8

Go to Step 7

7

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

Does the scan tool display the switch status as OFF?

Go to Step 16

Go to Step 14

8

  1. Open the appropriate door.
  2. With the scan tool, read the appropriate door jamb switch status.

Does the scan tool display the switch status as Active?

Go to Step 11

Go to Step 9

9

  1. Disconnect the appropriate mini wedge (door jamb switch).
  2. Connect a fused jumper wire between the door jamb switch signal circuit and the ground circuit of the door jamb switch.
  3. With the scan tool, read the appropriate door jamb switch status.

Does the scan tool display the switch status as Active?

Go to Step 17

Go to Step 10

10

  1. Connect a fused jumper wire between the door jamb switch signal circuit and a good ground.
  2. With the scan tool, read the appropriate door jamb switch status.

Does the scan tool display the switch status as Active?

Go to Step 21

Go to Step 13

11

  1. Remove the courtesy lamp relay.
  2. Connect a fused jumper wire between the courtesy lamp low control circuit and the ground circuit at the courtesy lamp relay.
  3. Open the drivers door.

Do the courtesy lamps light?

Go to Step 18

Go to Step 12

12

  1. Reinstall the courtesy lamp relay.
  2. Remove the inadvertent power relay.
  3. Using J 35616 , connect a fused jumper wire between the fused battery positive circuit and the inadvertent power relay output circuit at the relay socket.
  4. Open drivers door.

Do the courtesy lamps light?

Go to Step 19

Go to Step 20

13

Test the door jamb switch signal circuit between the mini wedge and the body control module (BCM). Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 20

14

Test the interior lamp defeat switch signal circuit of the BCM for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 20

15

Inspect for poor connections at the harness connector of the courtesy lamp. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 22

16

Inspect for poor connections at the harness connector of the headlamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 23

17

Inspect for poor connections at the harness connector of the mini wedge. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 24

18

Inspect for poor connections at the harness connector of the courtesy lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 25

19

Inspect for poor connections at the harness connector of the inadvertent power relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 26

20

Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 27

21

Repair the open in the ground circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 28

--

22

Replace the inoperative courtesy lamp.

Did you complete the repair?

Go to Step 28

--

23

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

Did you complete the replacement?

Go to Step 28

--

24

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

Did you complete the replacement?

Go to Step 28

--

25

Replace the courtesy lamp relay.

Did you complete the replacement?

Go to Step 28

--

26

Replace the inadvertent power relay.

Did you complete the replacement?

Go to Step 28

--

27

Important: Perform the setup procedure for the body control module.

Replace the body control module. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 28

--

28

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3