GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Interior Lights Schematics

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 switch to the ON position.
  2. Press both dome reading lamp switches in order to turn ON the dome reading lamps.
  3. Operate the roof rail courtesy lamp switches by pressing the switch toward the front of the vehicle.
  4. Determine which lamps are inoperative.

Are the dome reading lamps inoperative?

Go to Step 4

Go to Step 3

3

Are the roof rail courtesy lamps inoperative?

Go to Step 8

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

4

  1. Turn the ignition switch to the ON position.
  2. Press both dome reading lamp switches in order to turn ON the dome reading lamps.
  3. Determine if one of the dome reading lamps is inoperative or both dome reading lamps are inoperative.

Are both dome reading lamps inoperative?

Go to Step 6

Go to Step 5

5

  1. Replace the inoperative dome reading lamp bulb. Refer to Dome Lamp Replacement .
  2. Operate the reading lamp switch.

Does the reading lamp illuminate?

Go to Step 15

Go to Step 13

6

  1. Disconnect the dome and reading lamps connector.
  2. Turn the ignition switch to the ON position.
  3. Probe the supply voltage circuit of the reading lamps connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 11

7

Probe the ground circuit of the reading lamps connector with a test lamp that is connected to B+.

Does the test lamp illuminate?

Go to Step 13

Go to Step 12

8

  1. Replace the inoperative roof rail courtesy lamp. Refer to Roof Side Rail Lamp Replacement .
  2. Operate the roof rail courtesy lamp switch.

Does the roof rail courtesy lamp illuminate?

Go to Step 15

Go to Step 9

9

Test for an open or high resistance in the supply voltage circuit of the inoperative roof rail courtesy lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 10

10

Test for an open or high resistance in the ground circuit of the inoperative roof rail courtesy lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 14

11

Repair an open or high resistance in the supply voltage circuit of the dome and reading lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 15

--

12

Repair an open high resistance in the ground circuit of the dome and reading lamp . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 15

--

13

Replace the dome and reading lamp assembly. Refer to Dome Lamp Replacement .

Is the replacement complete?

Go to Step 15

--

14

Replace the dome and reading lamp assembly. Refer to Roof Side Rail Lamp Replacement .

Is the replacement complete?

Go to Step 15

--

15

  1. Connect all connectors and components that were disconnected.
  2. Verify that the reading lamps operate properly.

Do the reading lamps operate properly?

System OK

Go to Step 2