Test Description
WARNING: This page is about a different car, the 2007 Saturn Vue. 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: This step verifies that the body control module (BCM) is providing ground to the horn relay.
- 5: This step tests for voltage at the battery positive voltage terminal of the horn relay coil.
- 7: This step tests for voltage at the battery positive voltage terminal of the horn relay switch. The HORN fuse supplies power to the battery positive voltage terminal of the horn relay switch.
- 15: The horns need maximum current flow to operate properly. A high resistance (greater than 0.5 ohms) in the horn control circuit or the horn ground circuit could cause operating problems with the horns. Check the circuits for faults that would restrict current flow.
- 17: The horn relay control circuit includes the horn slip ring and the horn switch. The horn switch is part of the inflatable restraint steering wheel module. The horn slip ring and the horn switch must be tested for a high resistance, an open or a short to voltage when testing the relay control circuit. Refer to Circuit Testing and Wiring Repairs and Inflatable Restraint Steering Wheel Module Replacement
Horns Inoperative
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Depress the horn switch. Do the horns operate? |
Go to Step 3 | Go to Step 5 |
| 3 |
|
Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 4 |
| 4 | Test the BCM portion of the horn relay control circuit for a high resistance or an open. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
Go to Step 24 | Go to Step 13 |
| 5 |
|
Go to Step 6 | Go to Step 16 |
| 6 |
|
Go to Step 7 | Go to Step 17 |
| 7 | Connect a test lamp between the battery positive voltage circuit of the horn relay switch and a good ground. Does the test lamp illuminate? |
Go to Step 8 | Go to Step 18 |
| 8 | Momentarily connect a 15-amp fused jumper wire between the battery positive voltage circuit of the horn relay switch and the horn control circuit. Do the horns operate? |
Go to Step 14 | Go to Step 9 |
| 9 |
|
Go to Step 10 | Go to Step 19 |
| 10 |
|
Go to Step 11 | Go to Step 20 |
| 11 | Inspect for poor connections at the harness connector of the horn. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
Go to Step 24 | Go to Step 12 |
| 12 |
|
Go to Step 15 | Go to Step 23 |
| 13 | Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
Go to Step 24 | Go to Step 21 |
| 14 | Inspect for poor connections at the horn relay. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
Go to Step 24 | Go to Step 22 |
| 15 | Repair the high resistance in the horn control circuit or the horn ground circuit. (A resistance as low as 0.5 ohms could cause operating problems with the horns). Refer to Circuit Testing
and Wiring Repairs
. Did you complete the repair? |
Go to Step 24 | - |
| 16 | Repair the open or high resistance in the battery positive voltage circuit of the horn relay coil. Refer to Circuit Testing
and Wiring Repairs
. Did you complete the repair? |
Go to Step 24 | - |
| 17 |
IMPORTANT:
The horn switch is part of the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement
. To disable the SIR system refer to SIR DISABLING AND ENABLING
.Repair the open or short to voltage in the horn relay control circuit. The horn relay control circuit includes the horn slip ring and the horn switch. Refer to Circuit Testing
and Wiring Repairs
.Did you complete the repair? |
Go to Step 24 | - |
| 18 | Repair the open or high resistance in the battery positive voltage circuit of the horn relay switch. Refer to Circuit Testing
and Wiring Repairs
. Did you complete the repair? |
Go to Step 24 | - |
| 19 | Repair the open or high resistance in the horn control circuit. Refer to Circuit Testing
and Wiring Repairs
. Did you complete the repair? |
Go to Step 24 | - |
| 20 | Repair the open or high resistance in the horn ground circuit. Refer to Circuit Testing
and Wiring Repairs
. Did you complete the repair? |
Go to Step 24 | - |
| 21 |
IMPORTANT:
Perform the BCM programming procedure when replacing the BCM. Replace the BCM. Refer to Control Module References
.Did you complete the repair? |
Go to Step 24 | - |
| 22 | Replace the horn relay. Did you complete the replacement? |
Go to Step 24 | - |
| 23 | Replace the horns. Refer to Horn Replacement . Did you complete the replacement? |
Go to Step 24 | - |
| 24 | Operate the horns. Do the horns operate properly? |
System OK | Go to Step 1 |