Horns Always On. Chevrolet PJJ 2000

For 1990-2009 cars

### Test Description

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

1. Tests if ground is constantly being applied to the horn relay.

2. The horn control circuit includes the horn switch, the horn brush and the horn slip ring. The switch, brush and slip ring must be tested for a short to ground when testing the relay control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

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. With a scan tool, command the body control module BCM Horn Output ON and OFF.

Is the horn on at all times?

--

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

3

1. Turn OFF the ignition.
2. Disconnect the horn relay.

Is the horn on at all times?

--

Go to Step 8

Go to Step 4

4

1. Connect a test lamp between the battery positive voltage circuit of the horn relay coil and the horn relay control circuit.
2. Does the test lamp illuminate?

--

Go to Step 5

Go to Step 6

5 | Test the horn relay control circuit for a short to ground. (The horn relay control circuit includes the horn switch, the horn brush and the horn slip ring.) 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
6 | 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
7 | Inspect for poor connections at the BCM. 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
8 | Repair the short to voltage in the horn control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 11 | --
9 | Replace the horn relay. Refer to Horn Relay Replacement . Did you complete the replacement? | -- | Go to Step 11 | --
10 | Important: Perform the BCM programming procedure when replacing the BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control Systems. Replace the BCM. Refer to Body Control Module Replacement in Body Control Systems. Did you complete the replacement? | -- | Go to Step 11 | --
11 | Operate the horn. Does the horn operate properly? | -- | Go to Step 1 | System OK