GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Interior Lights Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn the ignition to the ON position.
  2. Close all the doors and turn the IP dimmer switch to the OFF position.

Are the courtesy lamps off?

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

Go to Step 3

3

  1. Install a scan tool.
  2. Turn ON the ignition , with the engine OFF.
  3. With a scan tool, observe the Courtesy Switch Input circuit status.

Is the Courtesy Switch Input circuit ON?

Go to Step 4

Go to Step 5

4

  1. Disconnect the headlamp switch connector.
  2. With a scan tool, observe the Courtesy Switch Input circuit status.

Is the Courtesy Switch Input circuit ON?

Go to Step 9

Go to Step 12

5

With a scan tool, observe the Driver Door Switch Input circuit status.

Is the Driver Door Switch Input circuit open?

Go to Step 6

Go to Step 7

6

  1. Disconnect the LF door lock connector.
  2. With a scan tool, observe the Driver Door Switch Input circuit status.

Is the Courtesy Switch Input circuit open?

Go to Step 10

Go to Step 13

7

With a scan tool, observe the Door Jamb Input circuit status.

Is the Door Jamb Input circuit open?

Go to Step 8

Go to Step 15

8

  1. Disconnect each door lock connector one at time.
  2. With a scan tool, observe the Door Jamb Input circuit status as each door lock connector is disconnected.

Does the Courtesy Switch Input circuit turn OFF when the door lock connectors are disconnected?

Go to Step 14

Go to Step 11

9

Test for a short to ground on the courtesy lamps control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 15

10

Test for a short to ground on the door unlatch switch signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 15

11

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

Did you find and correct the condition?

Go to Step 16

Go to Step 15

12

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Did you complete the repair?

Go to Step 16

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13

Replace the drivers door lock switch. Refer to Front Side Door Lock Replacement in Doors.

Did you complete the repair?

Go to Step 16

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14

Replace the inoperative door lock switch. Refer to Front Side Door Lock Replacement or Rear Door Lock Replacement in Doors.

Did you complete the repair?

Go to Step 16

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15

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

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the repair?

Go to Step 16

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16

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2