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 instrument panel (IP) dimmer switch is in the DOME position and the interior lamps override switch is on (interior courtesy lights). The interior courtesy lights 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 the IP dimmer switch to the DOME position.
  2. Use a test light in order to connect B+ and the body control module (BCM) connector C2 terminal C2.

Did the test lamp light?

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Go to Step 5

Go to Step  3

3

  1. Disconnect the headlamp/IP lamp dimmer switch electrical connector.
  2. Use a test lamp in order to connect B+ and the headlamp/IP lamp dimmer switch harness connector terminal A.

Did the test lamp light?

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Go to Step 4

Go to Step 6

4

  1. Disconnect the body control module (BCM) connector C2.
  2. Use a digital multi-meter (DMM) in order to measure the resistance between the BCM harness connector C2 terminal C2 and the headlamp/IP lamp dimmer switch harness connector terminal B.

Is the resistance within the specified range?

Less than 2 ohms

Go to Step 7

Go to Step 8

5

  1. Inspect the BCM connector C2 terminal C2 for faulty terminal contact and repair as needed.
  2. If the BCM connector C2 terminal  C2 is OK, replace the BCM. Refer to Body Control Module Replacement in Body Control Systems.

Is the repair complete?

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Go to Step 9

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6

Repair the following conditions in CKT 1450:

  1. A faulty connection
  2. An open circuit

Is the repair complete?

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Go to Step 9

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7

Replace the headlamp/IP lamp dimmer switch assembly.

Is the repair complete?

--

Go to Step 9

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8

Repair the following conditions in CKT 156:

    • A connection
    • An open circuit

Is the repair complete?

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Go to Step 9

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9

  1. Turn the ignition switch to the LOCK position.
  2. Reinstall any 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 a chime a number of times equivalent to the BCM type installed in 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 - Lighting Systems

System OK