GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2000 🢒 Jimmy - 4WD 🢒 Body and Accessories 🢒 Cellular Communication 🢒 OnStar Call Center Horn Command Inoperative

Test Description

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

  1. It is necessary for the OnStar® Call Center to command ON and OFF the horn.

    2.

  2. Tests that the problem is not within any other system.

Step

Action

Yes

No

Schematic Reference: OnStar Schematics

1

Did you perform the OnStar® Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Cellular Communication

2

  1. Activate the OnStar® Call Button.
  2. Wait for the Call Center operator to answer.
  3. Ask the operator for a Horn Honk command.

Does the Horn turn ON and OFF with each command?

Go to Step 6

Go to Step 3

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, command the Horn ON and OFF.

Does the Horn turn ON and OFF with each command?

Go to Step 4

Go to Diagnostic System Check - Horns

4

Inspect for poor connections at the VIU. 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 6

Go to Step 5

5

Replace the VIU. Refer to OnStar Vehicle Interface Unit Replacement

Did you complete the replacement?

Go to Step 6

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6

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2