GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Interior Lights Schematics

Connector End View Reference: Lighting Systems Connector End Views , Computer/Integrating Systems Connector End Views or Power Door Systems Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Verify that the courtesy/dome lamps are always on.

Do the courtesy/dome lamps operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Inspect for the following related body control module (BCM) module data parameters. Refer to Scan Tool Data List and Scan Tool Data Definitions for typical values and definitions:

    • The courtesy lamp switch
    • The dome lamp override switch
    • The driver door ajar switch
    • The passenger door ajar switch

Was a problem found?

Go to Step 4

Go to Step 7

4

Disconnect and test the switch of the affected input circuit for proper continuity in the open and closed positions. Refer to Circuit Testing .

Does the switch operate properly?

Go to Step 5

Go to Step 6

5

Test the signal and ground circuits of the affected input circuit for the following:

    • A short to ground
    • An open
    • A high resistance

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 7

6

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

Did you find and correct the condition?

Go to Step 11

Go to Step 9

7

Test for a short to ground in any of the courtesy lamp low control circuits.

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 8

8

Inspect for poor connections at the harness connector of the BCM. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 10

9

Replace the switch in the affected circuit. Refer to one of the following replacement procedures as applicable:

Did you complete the replacement?

Go to Step 11

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10

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

Did you complete the replacement?

Go to Step 11

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11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3