GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Interior Lights Schematics

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Close all of the vehicle's doors.
  2. Wait 10 seconds.

Are the courtesy lamps illuminated?

Go to Step 3

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

3

Use the Scan Tool in order to command the courtesy lamps OFF.

Do the courtesy lamps turn OFF?

Go to Step 4

Go to Step 8

4

  1. Close all of the vehicle's doors.
  2. With a scan tool, observe the Driver Door Ajar Sw. parameter and the Passenger Door Ajar Sw. parameter in the Lamp Status data list.

Does the scan tool indicate that both parameters are OFF?

Go to Step 11

Go to Step 5

5

Does the scan tool indicate that the Driver Door Ajar Sw. parameter is ON?

Go to Step 6

Go to Step 7

6

Disconnect the driver's door ajar switch.

Are the courtesy lamps illuminated?

Go to Step 9

Go to Step 12

7

Disconnect the passenger door ajar switches one at a time while observing the courtesy lamps.

Are the courtesy lamps illuminated?

Go to Step 10

Go to Step 12

8

  1. Disconnect the body control module (BCM).
  2. Test the courtesy lamp low control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 11

9

Test the driver's door ajar switch signal circuit for a short to ground. Refer Circuit Testing to Wiring Repairs and in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 11

10

Test the passenger's door ajar switch signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 11

11

Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 13

12

Replace the faulty door ajar switch. Refer to Front Side Door Lock Actuator Replacement or Rear Side Door Lock Actuator Replacement in Doors.

Did you complete the replacement?

Go to Step 14

--

13

Important: Perform the set up procedure for the body control module.

Replace the body control module. Refer to Body Control Module Replacement .

Did you complete the replacement?

Go to Step 14

--

14

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3