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 or Computer/Integrating Systems Connector End Views in Computer/Integrating Systems

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Verify that the courtesy lamps are always ON.

Do the courtesy lamps operate normally?

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

Go to Step 3

3

Inspect both door ajar switch input data parameters for the body control module (BCM). Refer to Scan Tool Data List and Scan Tool Data Definitions for typical values and definitions.

Was a problem found?

Go to Step 4

Go to Step 6

4

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

Is continuity present?

Go to Step 5

Go to Step 7

5

Test the signal and ground circuits of the affected input circuit for a short to ground, open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 8

6

Test the courtesy lamp supply voltage circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 8

7

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

Did you find and correct the condition?

Go to Step 11

Go to Step 9

8

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

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 Door Latch Replacement in Doors.

Did you complete the replacement?

Go to Step 11

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10

Replace the BCM. Refer to Control Module References in Computer/Integrating Systems 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