Test Description
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers on the diagnostic table.
- 4: Tests if ground is constantly being applied to the horn relay.
- 5: The horn relay control circuit includes the horn switch. The horn switch is part of the inflatable restraint steering wheel module. The horn switch must be tested for a short to ground when testing the relay control circuit.
Horns Always On Diagnostic Table
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | Did you perform the Diagnostic System Check-Horns? | Go to Step 2 | Go to Diagnostic System Check - Horns |
| 2 |
|
Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems |
| 3 |
|
Go to Step 8 | Go to Step 4 |
| 4 | Connect a test lamp between the battery positive voltage circuit of the horn relay coil and the horn relay control circuit. Does the test lamp illuminate? |
Go to Step 5 | Go to Step 6 |
| 5 |
IMPORTANT:
The horn switch is part of the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement
in SIR. To disable the SIR system refer to SIR Disabling and Enabling Zone 3
in SIR.Test the horn relay control circuit for a short to ground. The horn relay control circuit includes the horn switch. Refer to Circuit Testing
and toWiring 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 to 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 harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections
and toConnector 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 toWiring Repairs
in Wiring Systems. Did you complete the repair? |
Go to Step 11 | - |
| 9 | Replace the horn relay. Refer to Relay Replacement (Within an Electrical Center)Relay Replacement (Attached to Wire Harness)
. Did you complete the replacement? |
Go to Step 11 | - |
| 10 |
IMPORTANT:
Perform the BCM setup procedure when replacing the BCM. Replace the BCM. Refer toBody Control Module Replacement
in Body Control Systems.Did you complete the replacement? |
Go to Step 11 | - |
| 11 | Operate the horns. Do the horns operate properly? |
System OK | Go to Step 1 |