GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

DEFINITION: The interior courtesy lights do not activate when the driver's door is open. The interior courtesy lights activate when any other door is open.

1

Was the Body Control Module (BCM) Diagnostic System Check performed?

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Go to Step 2

Go to Diagnostic System Check - Body Control System in Body Control System

2

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.
  11. Open and close the driver's door.
  12. Listen to the chime.

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.

Does the chime sound when you open the driver's door?

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Go to Step 6

Go to Step 3

3

  1. Open the driver's door.
  2. Use a test lamp in order to connect between B+ and the (BCM) connector C2 terminal C1 by backprobing.

Did the test lamp light?

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Go to Step 6

Go to Step 4

4

  1. Disconnect the left front door lock switch electrical connector C1.
  2. Use a test light in order to connect between B+ and the left front door lock switch harness connector C1 terminal D.

Did the test lamp light?

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Go to Step 5

Go to Step 7

5

  1. Disconnect the BCM connector C2.
  2. Use a J 39200 digital multimeter (DMM) in order to measure the resistance between the BCM harness connector C2 terminal C1 and the left front door lock switch harness connector C1 terminal A.

Is the resistance within the specified range?

Less than 2 ohms

Go to Step 8

Go to Step 9

6

  1. Inspect the BCM connector C2 terminal C1 for poor terminal contact.
  2. Perform repairs as needed.

  3. If the BCM connector C1 terminal  C1 is OK, replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the repair?

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Go to Step 10

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7

Repair the following conditions in CKT 750:

    • A poor connection
    • An open

Did you complete the repair?

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Go to Step 10

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8

Replace the left front door lock switch assembly. Refer to Front Side Door Lock Replacement in Doors.

Did you complete the repair?

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Go to Step 10

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9

Repair the following conditions in CKT 159:

    • A poor connection
    • An open

Did you complete the repair?

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Go to Step 10

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10

  1. Turn the ignition switch to the LOCK position.
  2. Reinstall the connectors/components previously removed.
  3. Turn the ignition switch to the RUN position for 6 seconds.
  4. Turn the ignition switch to the LOCK position.
  5. Remove the BCM PRGRM fuse.
  6. Turn the ignition switch to the ACC position.
  7. The BCM sounds the chime a number of times equivalent to the BCM type installed on the vehicle.

  8. Within 1 second, turn the ignition switch from the ACC position to the LOCK position, then back to the ACC position.
  9. The BCM sounds any DTCs stored.

Are there any BCM DTCs present?

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Go to Diagnostic System Check - Body Control System in Body Control System

Go to Interior Lamps System Check