GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

IMPORTANT:

  1. Inspect the condition of the horn fuse. If the fuse is open, locate and repair source of overload.
  2. If any vehicle DTC's are set, refer to Diagnostic System Check - Body Control System .
  3. Verify that Ground G100 are clean and tight.

1

Remove the horn relay from the underhood bussed electrical center (UBEC).

Does the horn stop sounding?

--

Go to Step 3

Go to Step 2

2

Repair the short to B+ in CKT 1329 (DK GRN) between the UBEC and the left horn or the right horn (w/ RPO V22).

Is the repair complete?

--

System OK

--

3

Connect a test lamp from the horn relay cavity 86 to B+.

Does the test lamp light?

--

Go to Step 5

Go to Step 4

4

Replace the horn relay.

Is the repair complete?

--

System OK

--

5

  1. Disconnect the horn switch connector in the steering wheel.
  2. Connect a test lamp from the horn switch terminal (feed side) to B+.

Does the test lamp light?

--

Go to Step 7

Go to Step 6

6

Replace the horn switch.

Is the repair complete?

--

System OK

--

7

Locate and repair a short to ground in CKT   28 (BLK) between the horn switch and the horn relay or in the horn brush/slip ring.

Is the repair complete?

--

System OK

--