GM Service Manual Online
For 1990-2009 cars only

Diagnostic Aids

If the vanity mirror lighting is working on one side of a mirror but not on the other side, check the lamp bulb. If the vanity mirror lighting is working on one side of the car but not the other side, begin the diagnostic table at Step 3.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. In a vehicle equipped with a sunroof, the interior courtesy lamp is near the rearview mirror. It also serves as a map lamp. In a non-sunroof vehicle, the interior courtesy lamp is in the roof in the middle of the passenger compartment. There are separate map lamps near the rearview mirror. The vanity mirror lamps have the same fuse and ground as the courtesy lamp.

  2. The resistance of a vanity mirror lamp bulb is about 4.2 ohms.

Step

Action

Values

Yes

No

1

Check the operation of the courtesy lamp.

Does the courtesy lamp operate?

--

Go to Step 3

Go to Step 2

2

Repair the interior courtesy lamp system before completing this diagnostic table.

Does the key illumination lamp function after the courtesy lamp system has been repaired?

--

System OK

Go to Step 3

3

  1. Remove the sun visor.
  2. Check the voltage at terminal 1 of the wire harness connector for the vanity mirror.

Does the voltage measure within the specified range?

11-14 V

Go to Step 5

Go to Step 4

4

Repair the open circuit between fuse EF11 and terminal 1 of the vanity mirror connector.

Is the repair complete?

--

System OK

--

5

Connect an ohmmeter between ground and terminal 2 of the vanity mirror connector.

Does the ohmmeter indicate the specified value?

0 ohms

Go to Step 7

Go to Step 6

6

Repair the open circuit between terminal 2 of the vanity mirror connector and ground.

Is the repair complete?

--

System OK

--

7

Inspect the lamp bulbs.

Are the lamp bulbs OK?

--

Go to Step 9

Go to Step 8

8

Replace any faulty lamp bulbs.

Is the repair complete?

--

System OK

--

9

Replace the sun visor.

Is the repair complete?

--

System OK

--