GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  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

2

  1. Turn the headlamp switch to the ON position.
  2. Disconnect the headlamp dimmer switch connector C201C.
  3. Connect a fused jumper wire from terminal E12 (YEL wire) of connector C201C to ground.

Do the low beams light?

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Go to Step 3

Go to Step 4

3

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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4

Locate and repair CKT 525 (YEL) for an open between the underhood bussed electrical center (UBEC) and the dimmer switch.

Is the repair complete?

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System OK

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