GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Horns System Check?

--

Go to Step 2

Go to Horns System Check

2

Disconnect the horn relay.

Are the horns on?

--

Go to Step 4

Go to Step 3

3

Connect a test lamp between relay terminal 86 and terminal 85.

Does the test lamp light?

--

Go to Step 6

Go to Step 5

4

Repair a short to B+ in CKT 29 (DK GRN). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Horns System Check

--

5

Replace the horn relay. Refer to Horn Relay Replacement .

Is the repair complete?

--

Go to Horns System Check

--

6

  1. Disconnect the horn switch.
  2. Connect the horn relay.

Are the horns on?

--

Go to Step 9

Go to Step 8

7

Repair a short to ground in CKT 28 (BLK). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Horns System Check

--

8

Replace the horn switch.

Is the repair complete?

--

Go to Horns System Check

--

9

Disconnect the Remote Function Actuator (RFA) Module.

Are the horns on?

--

Go to Step 7

Go to Step 10

10

Replace the RFA Module. Refer to Remote Control Door Lock Receiver Replacement

in Keyless Entry.

Is the repair complete?

--

Go to Horns System Check

--