VUE FWD L4-2.4L (2008)
Battery positive voltage is applied at all times to the horn relay coil and the horn relay switch. Pressing the horn switch applies ground through the switch
contacts and the horn relay control circuit to the coil side of the relay, energizing the relay. Battery voltage is then applied through the switch side of the
relay, the HORN fuse, and the horn control circuit to the horn. The body control module (BCM) may also apply ground to the horn relay control circuit
as described above. The horn will sound as long as ground is applied to the horn relay control circuit.
Diagnostic Aids
If diagnosing a Horn - Poor Tone condition, inspect the following:
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Debris or water in the horn assembly
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Proper horn mounting hardware torque-Refer to Fastener Tightening Specifications (See: Specifications) .
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Debris in the joint where the horns attach to the vehicle
Reference Information
Schematic Reference
Horn Schematics (See: Diagrams/Electrical Diagrams)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Horns System Description and Operation (See: Description and Operation)
Electrical Information Reference
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Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics)
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Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics)
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Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics)
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Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
1. Ignition OFF, connect a test lamp between the horn fuse test point and ground.
2. Press and release the horn switch. The test lamp should turn ON and OFF when changing between the commanded states.
‹› If the test lamp does not illuminate or remains illuminated at all times, Refer to Horn Switch Circuit Test
3. Ignition ON, command the horn ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded
states.
‹› If the test lamp does not illuminate, test the control circuit terminal 18 at the BCM for a short to voltage or an open/high resistance. If the
circuit tests normal, replace the BCM.
4. Connect a 15A fused jumper wire between the horn fuse test point and B+. The horn should sound and emit a clear and even tone.
‹› If the horn does not sound, Refer to Horn Circuit Test.
‹› If the sound emitted is not clear and even, Refer to Horn - Poor Tone.
Circuit/System Testing
Horn Switch Circuit Test
1. Ignition OFF, disconnect the harness connector at the horn switch.
2. Test for less than 1 ohm between the ground circuit terminal 2 and ground.
‹› If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect the harness connector at the horn switch.
4. Disconnect the X3 harness connector at the underhood fuse block.
5. Connect a test lamp between B+ and the control circuit terminal 38.
6. Press and release the horn switch. The test lamp should turn ON and OFF when changing between the commanded states.
