GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

DEFINITION: The interior courtesy lights do not activate when any door is open.

1

Did you perform the Lighting Systems Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn On the Interior Lamps Override Switch (interior lamps enabled).
  2. Open and close each door and the liftgate individually to operate the courtesy lights.

Do the courtesy lights illuminate with each door and the liftgate open?

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Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Perform the BCM Input/Output test:

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

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

  9. 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.
  10. 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 grounds 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.

    Important: 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.

  11. Open and close each door and the liftgate individually
  12. Listen to the chime.

Does the chime sound when you open each door and the liftgate?

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Go to Step 7

Go to Step 4

4

Test the appropriate Door Ajar Input circuit for an open or for an inoperative door switch. Refer to Circuit Testing or Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 7

Go to Step 5

5

Do the courtesy lights illuminate when the Headlamp and IP Lamp Dimmer switch is in the DOME position?

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Go to Step 6

Go to Courtesy Lamps Inoperative

6

  1. Inspect the BCM connectors for poor terminal contact. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. Perform repairs as needed. Refer to Connector Repairs in Wiring Systems.

  3. If the BCM connectors are OK, replace the BCM. Refer to Body Control Module Replacement in Body Control Systems.

Did you complete the repair?

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Go to Step 7

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7

  1. Turn the ignition switch to the LOCK position.
  2. Reinstall the connectors/components previously removed.

Operate the system in order to verify the repair.

Did you find and correct the condition?

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System OK

Go to Step 2