GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Horns Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Horns

2

Verify the fault is present.

Does the system operate normally?

--

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Turn ON the ignition, with the engine OFF.
  2. Remove the horn relay.

Do the horns sound?

--

Go to Step 7

Go to Step 4

4

Connect a test lamp between the horn relay control circuit and battery (B+).

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 8

5

  1. Disable the SIR system. Refer to Disabling the SIR System in SIR.
  2. Disconnect the horn switch. Refer to Inflatable Restraint Steering Wheel Module Replacement in SIR.
  3. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

--

Go to Step 6

Go to Step 9

6

Repair the short to ground in the horn relay control circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 10

--

7

Repair the short to voltage in the input feed circuit to the horns. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 10

--

8

Replace the horn relay.

Did you complete the repair?

--

Go to Step 10

--

9

Replace the horn switch. Refer to Inflatable Restraint Steering Wheel Module Replacement in SIR.

Did you complete the repair?

--

Go to Step 10

--

10

Operate the system in order to verify the repair.

Did you find and correct the condition?

--

System OK

Go to Step 3