GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

DEFINITION: One or all of the following interior lights do not illuminate when the instrument panel (IP) dimmer switch is in the DOME position or a door is opened.

    • Cargo lamp
    • Dome lamp
    • IP courtesy lamps

1

Did you perform the Lighting Systems Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn ON the Interior Lamps Override Switch (interior lamps enabled).
  2. Turn the Headlamp and IP Lamp Dimmer Switch to the DOME position.

Are all the courtesy lamps illuminated?

--

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Determine if one or all of the courtesy lamps are inoperative.

Is one of the courtesy lamps inoperative?

--

Go to Step 10

Go to Step 4

4

Perform the BCM Input/Output test:

  1. Turn off the IP dimmer switch.
  2. Turn ON the interior lamps override switch (interior courtesy lamps enabled).
  3. Turn the ignition switch to the LOCK position.
  4. Remove the BCM PRGRM fuse.
  5. Turn the ignition switch to the ACC position. The BCM sounds 4 chimes, indicating the BCM type installed on the vehicle.
  6. Within 1 second, turn the ignition switch from the ACC position to the LOCK position and back to the ACC position.
  7. The BCM sounds any stored DTCs.

  8. Turn the I/P dimmer switch to the DOME position.
  9. The BCM enters the Input/Output test.

  10. Cycle the IP dimmer switch from the DOME position to the OFF position and back to the DOME position in order to move to the next test.
  11. The BCM runs the Input/Output test in numerical order.

    The BCM flashes the fasten belts indicator and sounds the chime a number equivalent to the Input/Output test number:

    • Test 1 de-energizes CKT 1393 (protected courtesy light output).
    • Test 2 energizes CKT 1393.
    • Test 3 deactivates CKT 690 (courtesy lights control).
    • Test 4 turns on the exterior lights.
    • Test 5 sounds the horn relay for 25 ms.
    • Test 6 turns on the security indicator lamp.
    • Test 7 turns off the theft security indicator lamp.

NOTE: While the BCM is performing the Input/Output test, the chime sounds when any of the BCM inputs is activated. Example: The chime sounds when any Door is opened.

Does the BCM enter the Input/Output test?

--

Go to Step 5

Go to Step 7

5

  1. Cycle the IP dimmer switch from the DOME position to the OFF position and back to the DOME position in order to move to test 2.
  2. Turn ON the Roof Rail Reading Lamps and the Sunshade Lighted Vanity Mirror Lamps.

Do the Roof Rail Reading Lamps and the Sunshade Lighted Vanity Mirror Lamps illuminate?

--

Go to Step 6

Go to Step 8

6

Test the Courtesy Lights Control Output circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 9

7

Test the Interior Lights On Request Input circuit for an open or an inoperative headlamp and IP lamp Dimmer switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

If the Headlamp and IP Lamp Dimmer Switch is inoperative, refer to Headlamp Switch Replacement .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 9

8

Test the Protected B+ Output Courtesy Lights circuit for an open or for an inoperative Interior Lamps Override Switch . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

If the Interior Lamps Override Switch is inoperative, refer to Dome Lamp Override Switch Replacement .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 9

9

  1. Inspect the BCM connectors for faulty terminal contacts. Refer to Testing for Intermittent Conditions and Poor Connections or Connector Repairs in Wiring Systems.
  2. If the BCM connectors are OK, replace the BCM. Refer to Body Control Module Replacement in Body Control Systems.

Did you find and correct the condition?

--

Go to Step 12

--

10

Repair the open or high resistance in the inoperative courtesy lamp power supply or ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 12

Go to Step 11

11

Replace the inoperative courtesy lamp. Refer to the appropriate procedure.

    •  Dome Lamp Replacement
    •  Cargo Lamp Replacement

Did you complete the repair?

--

Go to Step 12

--

12

  1. Turn the ignition switch to the LOCK position.
  2. Reinstall any connectors/components that were previously removed.
  3. Operate the system to verify the repair

Did you find and correct the condition?

--

System OK

Go to Step 2