GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

SCHEMATIC REFERENCE: Headlights Schematics

1

Did you perform the Lighting Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Disconnect the headlamp switch connector.

Did the headlamps turn OFF?

Go to Step 8

Go to Step 3

3

Test the headlamp switch input circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 4

4

Disconnect the lighting control module (LCM).

Did the headlamps turn OFF?

Go to Step 5

Go to Step 7

5

Inspect for poor connections at the LCM connectors. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 6

6

Replace the LCM. Refer to Lamp Control Module Replacement .

Did you complete the replacement?

Go to Step 10

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7

Repair short to power in the low beam headlamp power feed circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 10

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8

Inspect for poor connections at the headlamp switch connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 9

9

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Did you complete the replacement?

Go to Step 10

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10

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2