GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2000 🢒 LeSabre 🢒 Body and Accessories 🢒 Horns 🢒 Horns Always On

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Listen for an audible click when the horn relay operates. Command both the ON and OFF states. Repeat the commands as necessary.

    2.

  2. This step verifies that the dash integration module (DIM) and the horn switch is providing ground to the horn relay.

    3.

  3. This step tests if ground is constantly being applied to the horn relay.

    4.

  4. The control circuit includes the horn switch which is part of the steering wheel module inflatable restraint. The switch must be tested for a short to ground when testing the relay control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems, and Inflatable Restraint Steering Wheel Module Replacement In SIR.

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

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Using a scan tool, command the dash integration module (DIM) horn output ON and OFF.
  4. Activate the horn switch.

Does the horn relay turn ON and OFF both with each command of the scan tool and horn switch?

--

Go to Step 6

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the horn relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the control circuit of the horn relay and the coil side feed circuit of the horn relay.
  5. Using a scan tool, command the DIM horn output ON and OFF.
  6. Activate the horn switch.

Does the test lamp turn ON and OFF both with each command of the scan tool and horn switch?

--

Go to Step 7

Go to Step 4

4

Does the test lamp remain illuminated with each command or switch activation?

--

Go to Step 5

Go to Step 6

5

Caution: When you are performing service on or near the SIR components or the SIR wiring, you must disable the SIR system. Refer to Disabling the SIR System. Failure to follow the correct procedure could cause air bag deployment, personal injury, or unnecessary SIR system repairs.

Important:: The horn switch is part of the steering wheel module inflatable restraint. Refer to Inflatable Restraint Steering Wheel Module Replacement in SIR.

  1. Disable the SIR system. Refer to Disabling the SIR System in SIR.
  2. Test the control circuit of the horn relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 8

6

Test the feed circuit of the horn assembly for a short to B+. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 7

7

Inspect for poor connections at the horn relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 9

8

Inspect for poor connections at the harness connector of the DIM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 10

9

Replace the horn relay. Refer to Horn Relay Replacement .

Did you complete the replacement?

--

Go to Step 11

--

10

Replace the DIM. Refer to Dash Integration Module Replacement in Body Control System.

Did you complete the replacement?

--

Go to Step 11

--

11

Operate the vehicle within the Conditions for Running the symptom.

Does the symptom reoccur?

--

Go to Step 1

System OK