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?

--

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

Go to Step 2

2

Do the headlamps (high beams) function properly?

--

Go to Step 3

Go to Headlamps Inoperative - High Beams

3

  1. Turn the headlamp switch to the head position.
  2. Switch to high beams.
  3. Using the scan tool, read the high beam switch status under the BCM.

Does the scan tool show ON?

--

Go to High Beam Indicator Malfunction in Instrument Panel, Gauges and Console

Go to Step 4

4

Locate and repair CKT 524 (PPL) for a open between the BCM and switch.

If no open is found, replace the BCM. Refer to Body Control Module Replacement in body control system.

Is the repair complete?

--

System OK

--