GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Interior Lights Dimming Schematics

Connector End View Reference: Master Electrical Component List

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Verify that the interior backlighting is inoperative.

Does the interior backlighting operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

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 .

    • 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 .

    • 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 .

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 (BCM). Refer to Circuit Testing and Wiring Repairs .

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

Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

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