GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

DEFINITION: One or all of the following park lamps are inoperative: taillamps, headlamps position lamps. license lamps

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Place the headlamp/IP Dimmer switch to the PARK position.

Are the park lamps operating properly?

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

Go to Step 3

3

Are all of the park lamps inoperative?

Go to Step 7

Go to Step 4

4

Is only one of the park lamps inoperative?

Go to Step 10

Go to Step 5

5

Determine which of the following park lamps are inoperative.

    • Headlamp position lamps
    • Rear license lamps
    • Taillamps

Are the taillamps inoperative?

Go to Step 11

Go to Step 6

6

Determine which of the following park lamps are inoperative.

    • Headlamp position lamps
    • Rear license lamps

Are the headlamp position lamps inoperative?

Go to Step 12

Go to Step 13

7

Inspect the PARK LP fuse.

Is the fuse open?

Go to Step 20

Go to Step 8

8

  1. Turn the headlamp/IP lamp dimmer switch to the PARK position.
  2. Use a test light in order to backprobe the headlamp/IP lamp dimmer switch harness connector between terminal R and ground.

Did the test lamp light?

Go to Step 19

Go to Step 9

9

Use a test light in order to backprobe the headlamp/IP lamp dimmer switch harness connector between terminal O and ground.

Did the test lamp light?

Go to Step 17

Go to Step 18

10

Test for an open or a high resistance in the inoperative park lamp power supply circuit or ground supply circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition.

Go to Step 22

Go to Step 21

11

Test for an open, high resistance, or short to ground in the tailamps power supply circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition.

Go to Step 22

Go to Step 14

12

Test for an open or high resistance in the headlamp position lamps power supply circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition.

Go to Step 22

Go to Step 15

13

Test for an open or high resistance in the rear license lamps power supply circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition.

Go to Step 22

Go to Step 16

14

Repair an open or high resistance in the tailamps ground supply circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 22

--

15

Repair an open or high resistance in the headlamp position lamps ground supply circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 22

--

16

Repair an open or high resistance in the rear license lamps ground supply circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 22

--

17

Replace the headlamp/IP lamp dimmer switch. Refer to Headlamp Switch Replacement .

Is the repair complete?

Go to Step 22

--

18

Repair an open or high resistance in the headlamp and IP lamp dimmer switch battery positive voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 22

--

19

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

Is the repair complete?

Go to Step 22

--

20

Repair a short to ground in battery positive voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 22

--

21

Replace the inoperative parklamp. Refer to the appropriate procedure.

    • Taillamp replacement refer to Tail Lamp Replacement
    • License lamp replacement refer to Rear License Lamp Replacement
    • Headlamp position lamp replacement refer to Headlamp Position Lamp Replacement

Is the repair complete?

Go to Step 22

22

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2