B1897 – Horn Switch Circuit Failure

The ODBII code B1897 indicates a malfunction in the horn switch circuit, which may involve issues with the switch itself, wiring, or related components affecting the horn’s operation.

The severity of ODBII code B1897 Horn Switch Circuit Failure is generally considered low.

Common Causes For: B1896 Driver’s / Passenger’s Door Ajar Output Circuit Short to Battery

• Faulty horn switch
• Damaged wiring or connectors
• Short circuit in the horn circuit
• Open circuit in the horn circuit
• Faulty body control module (BCM)
• Corrosion in connectors
• Poor ground connection

Common misdiagnosis for B1897 Horn Switch Circuit Failure

• Faulty horn relay
• Wiring issues or shorts in the horn circuit
• Defective horn assembly
• Malfunctioning body control module (BCM)
• Issues with the steering wheel clock spring
• Problems with the vehicle’s electrical system or ground connections
• Incorrectly diagnosed airbag system faults

Common Troubleshooting Steps

When dealing with OBD-II code B1897, which indicates a “Horn Switch Circuit Failure,” there are several common troubleshooting steps you can follow to diagnose and potentially resolve the issue. Here’s a structured approach:

• Check the Vehicle’s Owner Manual: Refer to the vehicle’s service manual for specific information related to the horn switch circuit and wiring diagrams.
• Visual Inspection: Inspect the horn switch and associated wiring for any visible damage, corrosion, or loose connections.
• Check the horn itself to ensure it is not damaged or disconnected.
• Test the Horn: Directly connect the horn to the battery to see if it functions. If it does not sound, the horn may be faulty and needs replacement.
• Inspect the Horn Switch: Remove the steering wheel cover (if applicable) to access the horn switch.
• Check for any signs of wear or damage on the switch itself.
• Use a multimeter to test the continuity of the horn switch when pressed.
• Check the Wiring and Connectors: Inspect the wiring harness for any frayed wires or poor connections.
• Ensure that all connectors are secure and free of corrosion.
• Test the Relay: Locate the horn relay in the fuse box and test it. You can swap it with a similar relay to see if the horn starts working.
• If the relay is faulty, replace it.
• Scan for Additional Codes: Use an OBD-II scanner to check for any other related trouble codes that may provide more context to the issue.
• Check the Ground Connection: Ensure that the horn and horn switch have a good ground connection. A poor ground can cause circuit failures.
• Inspect the Body Control Module (BCM): If all other components check out, the issue may lie within the BCM. Check for any software updates or faults in the module.
• Clear the Code and Test Drive: After performing repairs, clear the code using an OBD-II scanner and take the vehicle for a test drive to see if the code returns.1
• Consult a Professional: If the issue persists after all troubleshooting steps, it may be best to consult a professional mechanic or an automotive electrician for further diagnosis.Conclusion By following these steps, you should be able to identify and resolve the issue related to the B1897 code. Always ensure safety precautions are taken when working on electrical components in your vehicle.