GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Important: The 9 CKT (BRN) is monitored by the BCM, and will set a code if a short-to-ground occurs within the 9 CKT (BRN).

Check for inoperative bulbs before beginning diagnostic procedure.

1

Did you perform the Lighting Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Turn the headlamp and panel dimmer switch to the PARK position.

Are all of the component illumination lamps inoperative?

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Go to Step 3

Go to Step 4

3

Use a test lamp in order to backprobe from the headlamp and panel dimmer switch CKT 9 (BRN) cavity S to ground.

Does the test lamp light?

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Go to Step 7

Go to Step 8

4

Inspect for an open in the following locations:

    • CKT 9 (BRN) between splice S217 and the affected lamp(s)
    • CKT 550 (BLK) between G107 and the affected lamp(s)
    • CKT 750 (BLK) between G110 and the affected lamp(s)
    • CKT 1050 (BLK) and G200 and the affected lamp(s)

Did you find any opens?

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Go to Step 5

Go to Step 6

5

Repair the open in the following locations:

    • CKT 9 (BRN) between splice S217 and the affected lamp(s)
    • CKT 550 (BLK) between G107 and the affected lamp(s)
    • CKT 750 (BLK) between G110 and the affected lamp(s)
    • CKT 1050 (BLK) and G200 and the affected lamp(s)

Are the repairs complete?

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Go to Step 9

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6

Replace the affected lamps.

Are the replacements complete?

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Go to Step 9

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7

Repair the open in CKT 9 (BRN) between splice S217 and the headlamp and panel dimmer switch.

Is the repair complete?

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Go to Step 9

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8

Replace the headlamp and panel dimmer switch Headlamp Switch Replacement .

Is the replacement complete?

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Go to Step 9

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9

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2