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

DEFINITION: All instrument panel (I/P) courtesy dome and roof rail courtesy lamps are inoperative from any door or the I/P dimmer switch.

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Turn ON the ignition, with the engine OFF.
  2. Open and close all of the vehicle doors.
  3. Observe the courtesy lamps.

Do the courtesy lamps illuminate when each door is opened?

Go to Step 4

Go to Step 3

3

Are the courtesy lamps inoperative from the instrument panel (I/P) dimmer switch also ?

Go to Step 4

Go to Step 7

4

  1. Disconnect the interior lamp I/P dimmer switch.
  2. Install a jumper between the courtesy lamp switch on signal circuit and I/P dimming return circuit.

Do the courtesy lamps illuminate?

Go to Step 15

Go to Step 5

5

Test for a poor connection, open or a short to ground in the INT light fuse voltage supply circuit of the body control module (BCM). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 6

6

Test for short to ground or an open in the courtesy lamp supply voltage circuit of the BCM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 8

7

  1. Close all of the vehicle doors, except the inoperative door.
  2. Disconnect the inoperative door lock switch.
  3. Connect a 3-amp fused jumper wire between the door open switch signal wire and ground.

Do the courtesy lamps illuminate?

Go to Step 10

Go to Step 11

8

Test for a poor connection open, or a short to battery positive voltage in the courtesy lamp on signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 9

9

Test for a short to battery positive voltage or a open in the I/P dimming return circuit of the BCM. 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

10

Test the ground circuit of the inoperative door lock switch for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 12

11

Test the inoperative door lock switch open circuit for an open or high resistance. 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 a poor connections at the harness connector of the inoperative door lock 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 inoperative door lock switch. Refer to Front Side Door Lock Replacement or to Rear Door Lock Replacement in Doors.

Did you complete the replacement?

Go to Step 17

--

15

Replace the I/P dimmer switch. Refer to Instrument Panel Lamp Dimmer Switch Replacement .

Did you complete the repair?

Go to Step 17

--

16

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 17

--

17

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3