GM Service Manual Online
For 1990-2009 cars only

Courtesy Lamps Inoperative I/PCourtesy or Ign Switch

Step

Action

Value(s)

Yes

No

DEFINITION: I/P courtesy lamp or ignition switch illumination bulb does not turn on when the courtesy lights are on.

1

Check the inoperative lamp bulb filament.

Is the lamp bulb filament open?

--

Go to Step 3

Go to Step 2

2

  1. Disconnect the inoperative courtesy lamp bulb.
  2. Turn the ignition switch from off to on.
  3. Turn the I/P lamp dimmer switch to the DOME position.
  4. Using a test lamp, connect between the inoperative lamp harness connector terminal A and ground.

Is the test lamp on?

--

Go to Step 4

Go to Step 5

3

Replace the inoperative lamp bulb. Refer to Instrument Panel Courtesy Lamp Bulb Replacement for service procedure. Refer to Bulb Usage for bulb specifications.

Is the repair complete?

--

System OK

--

4

Repair poor connection or open in circuit 156.

Is the repair complete?

--

Go to Step 6

--

5

Repair poor connection or open in circuit 1732.

Is the repair complete?

--

Go to Step 6

--

6

  1. Turn the ignition switch off.
  2. Reinstall the connectors/components removed.
  3. Check for BCM DTCs. Refer to Diagnostic Trouble Code (DTC) Displaying in Body Control System.

Are there any DTCs stored in the BCM?

--

Go to Diagnostic System Check - Body Control System in Body Control System

System OK

Courtesy Lamps Inoperative All Courtesy Lights

Step

Action

Value(s)

Yes

No

DEFINITION: None of the interior lamps turn on when a door is open, the I/P lamp switch is in the DOME position, or any of the interior lighting modes is active.

1

Check the INADV POWER BUS fuse located in the fuse block.

Is the INADV POWER BUS fuse open?

--

Go to Step 2

Go to Step 3

2

  1. Replace the INADV POWER BUS fuse.
  2. Open, then close any vehicle door.
  3. Check the INADV POWER BUS fuse again.

Is the INADV POWER BUS fuse open again?

--

Go to Step 7

Go to Step 3

3

Was the BCM diagnostic system check performed?

--

Go to Step 4

Go to Diagnostic System Check - Body Control System in Body Control System

4

  1. Turn the ignition switch off.
  2. Connect scan tool to the Data Link Connector (DLC).
  3. Turn the ignition switch on.
  4. Using the scan tool, monitor the status of the BATTERY POWER 3.

Does scan tool display that the status of the BATTERY POWER 3 is present?

--

Go to Step 5

Go to Step 6

5

  1. Turn the ignition switch from off to on.
  2. Turn the I/P dimmer switch to the DOME position.
  3. Using a test lamp, backprobe between the BCM connector C3 terminal F and ground.

Is the test lamp on?

--

Go to Step 8

Go to Step 9

6

Using a test lamp, backprobe between the BCM connector C3 terminal K and ground.

Is the test lamp on?

--

Go to Step 9

Go to Step 10

7

Repair short to ground in circuit 240 or 1732.

Is the repair complete?

--

Go to Step 11

--

8

Repair poor connection or open in circuit 1732 between the BCM connector C3 terminal F and S242.

Is the repair complete?

--

Go to Step 11

--

9

    • Inspect the BCM connector for a poor terminal contact. Perform the repairs as necessary.
    • If the BCM connections are OK, then replace the BCM. Refer to Body Control Module Replacement in Body Control System.
    • After the BCM replacement, perform the Setup New BCM procedure. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Is the repair complete?

--

Go to Step 11

--

10

Repair poor connection or open in circuit 240.

Is the repair complete?

--

Go to Step 11

--

11

  1. Turn the ignition switch off.
  2. Reinstall the connectors/components removed.

  3. Check for BCM DTCs. Refer to Diagnostic Trouble Code (DTC) Displaying in Body Control System.

Are there any DTCs stored in the BCM?

--

Go to Diagnostic System Check - Body Control System in Body Control System

System OK