GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Lighting Systems Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Does the underhood lamp operate properly?

--

Go to Step 3

Go to License, Underhood and Cornering Lamps Inoperative

3

  1. Disconnect the license plate lamp bulb.
  2. Connect a test lamp between the license plate lamp power feed circuit and a good ground.
  3. Turn ON the ignition, with the engine OFF.
  4. Turn ON the headlights.

Does the test lamp illuminate?

--

Go to Step 4

Go to Step 6

4

Connect a test lamp from the license plate lamp power feed circuit to the license plate lamp ground circuit.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 7

5

Replace the license plate lamp bulb. Refer to Rear License Lamp Replacement .

Did you complete the replacement?

--

Go to Step 8

--

6

Repair high resistance or open in license plate lamp power circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 8

--

7

Repair high resistance or open in license plate lamp ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 8

--

8

Operate the system in order to verify the repair.

Did you find and correct the condition?

--

System OK

Go to Step 2