GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Lighting Systems Connector End Views

1

Did you review the Exterior Lighting Systems Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Exterior Lighting Systems Description and Operation

2

Verify that the marker lamps are inoperative.

Do the marker lamps operate normally?

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

Go to Step 3

3

Turn the headlamp switch to the HEAD position.

Are all of the marker lamps inoperative?

Go to Step 4

Go to Step 5

4

Test the following circuits for an open, high resistance or short to ground. Refer to Circuit Testing in Wiring Systems:

    • Battery positive voltage
    • Park lamp switch signal

Was a problem found?

Go to Step 8

Go to Step12

5

Inspect the inoperative bulb for an open filament.

Is the bulb filament open?

Go to Step 13

Go to Step 6

6

Connect a test lamp from ground to the front park lamps supply voltage circuit at the inoperative bulb socket. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

Go to Step 11

Go to Step 7

7

Inspect FR PARK fuse in underhood fuse block.

Is the fuse good?

Go to Step 10

Go to Step 9

8

Repair the open, high resistance or short to ground in one of the following circuits. Refer to Wiring Repairs in Wiring Systems:

    • Battery positive voltage
    • Park lamp switch signal

Is the repair complete?

Go to Step 14

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9

Repair the short to ground in the front park lamps supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 14

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10

Repair the open or high resistance in the front park lamps supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 14

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11

Repair the open or high resistance in the ground circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 14

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12

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Is the repair complete?

Go to Step 14

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13

Replace the inoperative bulb.

Is the repair complete?

Go to Step 14

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14

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3