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. Ensure the instrument panel dimmer switch is not in the DOME position.
  2. Close all of the vehicle's doors.
  3. 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 6

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 13

Go to Step 5

5

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

Go to Step 8

Go to Step 9

6

Disconnect the instrument panel dimmer switch.

Are the courtesy lamps illuminated?

Go to Step 7

Go to Step 12

7

  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 17

Go to Step 13

8

  1. Disconnect the driver's door ajar switch.
  2. Observe the Driver Door Ajar Sw. parameter as you disconnect the switch.

Does the scan tool indicate that the Driver Door Ajar Sw. parameter is OFF when the driver door jamb switch is disconnected?

Go to Step 15

Go to Step 10

9

  1. Disconnect the passenger door ajar switch or door jamb switches one at a time.
  2. Observe the Passenger Door Ajar Sw. parameter as you disconnect each switch.

Does the scan tool indicate that the Passenger Door Ajar Sw. parameter is OFF when one of the passenger door jamb switches is disconnected?

Go to Step 15

Go to Step 11

10

Test the driver'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 17

Go to Step 13

11

Test the passenger's door 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 17

Go to Step 13

12

Inspect for poor connections at the harness connector of the instrument panel dimmer switch. 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 17

Go to Step 14

13

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 17

Go to Step 16

14

Replace the instrument panel dimmer switch.

Did you complete the replacement?

Go to Step 17

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15

Replace the inoperative door ajar switch or door jamb switch.

Did you complete the replacement?

Go to Step 17

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16

Important: Perform the set up procedure for the body control module. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

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

Did you complete the replacement?

Go to Step 17

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17

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2