GM Service Manual Online
For 1990-2009 cars only

Courtesy/Reading Lamps Inoperative Roof Rail

Step

Action

Value(s)

Yes

No

DEFINITION: The roof rail courtesy/reading lamps do not turn on when neither the courtesy lamps are on, nor the roof rail courtesy/reading lamp switches are on.

1

Check the roof rail courtesy/reading lamp bulb filament.

Is the roof rail courtesy/reading lamp bulb filament open?

--

Go to Step 5

Go to Step 2

2

  1. Disconnect the roof rail courtesy/reading lamp electrical connector.
  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 roof rail courtesy/reading lamp harness connector terminal A and ground.

Is the test lamp on?

--

Go to Step 3

Go to Step 6

3

Using a test lamp, connect between the roof rail courtesy/reading lamp harness connector terminals A and B.

Is the test lamp on?

--

Go to Step 4

Go to Step 7

4

Using a test lamp, connect between the roof rail courtesy/reading lamp harness connector terminal A and C.

Is the test lamp on?

--

Go to Step 8

Go to Step 9

5

Replace the roof rail courtesy/reading lamp bulb. Refer to Bulb Usage for bulb specifications.

Is the repair complete?

--

System OK

--

6

Repair poor connection or open in circuit 1732.

Is the repair complete?

--

Go to Step 10

--

7

Repair poor connection or open in circuit 157.

Is the repair complete?

--

Go to Step 10

--

8

Replace the roof rail courtesy/reading lamp assembly. Refer to Roof Side Rail Lamp Replacement for service procedure.

Is the repair complete?

--

Go to Step 10

--

9

Repair poor connection or open in circuit 850.

Is the repair complete?

--

Go to Step 10

--

10

  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/Reading Lamps Inoperative Inside Rear View Mirror

Step

Action

Value(s)

Yes

No

DEFINITION: The inside rear view mirror reading lamps do not turn on when the inside rear view mirror reading lamps switches are on.

1

Check the filament of the inside rear view mirror reading lamps bulb(s).

Any bulb filament open?

--

Go to Step 4

Go to Step 2

2

  1. Disconnect the inside rear view mirror reading lamps electrical connector.
  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 light, connect between the inside rear view mirror reading lamps harness connector terminal C (terminal 7 if equipped with auto day-night mirror RPO DD8) and ground.

Is the test light on?

--

Go to Step 3

Go to Step 5

3

Using a test light, connect between the inside rear view mirror reading lamps harness connector terminals B and C (terminals 2 and 7 if equipped with auto-day-night mirror RPO DD8).

Is the test lamp on?

--

Go to Step 6

Go to Step 7

4

Replace the inside rear view mirror reading lamps bulb(s). Refer to Bulb Usage for bulb specifications.

Is the repair complete?

--

System OK

--

5

Repair poor connection or open in circuit 1732.

Is the repair complete?

--

Go to Step 8

--

6

Replace the inside rear view mirror reading lamps assembly. Refer to Inside Rearview Mirror Replacement in Stationary Windows.

Is the repair complete?

--

Go to Step 8

--

7

Repair poor connection or open in circuit 850.

Is the repair complete?

--

Go to Step 8

--

8

  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