GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Interior Lights Dimming Schematics

1

Did you perform the Lighting Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Verify that the interior backlighting is inoperative.

Does the interior backlighting operate normally?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Are all of the interior backlighting lamps inoperative?

Go to Step 5

Go to Step 4

4

Test for an open or high resistance in the following circuits. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

    • The instrument panel lamps dimming control
    • The ground

Did you find and correct a condition?

Go to Step 10

Go to Step 6

5

Test for the following conditions. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

    • Short to ground in the instrument panel lamps dimming control circuit
    • Short to voltage in the dimming input circuit
    • Open or high resistance in the dimming return circuit

Did you find and correct a condition?

Go to Step 10

Go to Step 7

6

Inspect for poor connections at the harness connector of the affected lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 8

7

Inspect for poor connections at the harness connector of the body control module. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 9

8

Replace the affected lamp or internal lamp component.

Did you complete the replacement?

Go to Step 10

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9

Important: Perform the setup procedure for the BCM.

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

Did you complete the replacement?

Go to Step 10

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10

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3