1. Turn the ignition OFF.
2. Connect a scan tool.
3. Turn the ignition to the ON position.
4. Using the scan tool, check for any DTCs in the body control module (BCM).

Does the scan tool show any DTCs ?

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Go to Diagnostic System Check - Body Control System in Body Control System

Go to Step 2

1. Turn the headlamp switch to the ON position.
2. Disconnect the headlamp dimmer switch connector C201C.

Are both the high and the low beam off?

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Go to Step 3

Go to Step 5

Connect a test lamp from terminal E12 (YEL wire) to ground, then from terminal E11 (PPL wire) to ground at connector C201C.

Does the test lamp light at both terminals?

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Go to Step 4

Go to Step 6

Replace the headlamp dimmer switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column - Tilt.

Is the repair complete?

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System OK

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Locate and repair CKT 524 (PPL) for high beam or CKT 525 (YEL) wire for the low beam for a short to ground.

Is the repair complete?

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System OK

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Locate and repair CKT 524 (PPL) for high beam or CKT 525 (YEL) for the low beam for an open between the switch and the underhood bussed electrical center (UBEC).

Is the repair complete?

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System OK

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