GM Service Manual Online
For 1990-2009 cars only

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

  1. Press and release the LH horn switch.
  2. Press and release the RH horn switch.

Both horns sound for as long as the switches are pressed.

One or both horns are inoperative. Refer to Horns Inoperative for diagnosis.

2

  1. Install the scan tool.
  2. Select the miscellaneous test in special functions.
  3. Command the BCM to turn both of the horns ON.

Both horns sound for as long as the BCM has the horns turned ON.

One or both of the horns are inoperative. Refer to Horns Inoperative for diagnosis.

3

  1. Press and release the LH horn switch.
  2. Press and release the RH horn switch.

Both horns sound for as long as the switches are pressed.

The horns are ON at all times. Refer to Horns Always On for diagnosis.

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.