Horn Switch Circuit Malfunction (B1897)
Diagnostic trouble code B1897 indicates that the Body Control Module (BCM) or Steering Column Control Module (SCCM) has detected a fault in the horn switch circuit. This typically means the voltage signal from the horn switch is out of range—such as a short to ground, short to battery, open circuit, or high resistance—when the horn button on the steering wheel is pressed or released.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty or worn horn switch (clockspring/clock spring contact)
- Damaged, corroded, or shorted wiring or connectors in the horn switch circuit
- Internal failure of the Body Control Module (BCM) or Steering Column Control Module (SCCM)
- Defective horn relay affecting circuit feedback
3. Symptoms You Will Notice
- Horn does not sound when pressed
- Horn sounds continuously or intermittently without pressing the button
4. Step-by-Step Diagnosis
Check for related technical service bulletins (TSBs) for the vehicle.
Inspect the horn fuse and relay; replace if blown or faulty.
Test the horn switch and clockspring for continuity and proper operation.
Inspect wiring and connectors in the horn circuit for damage, corrosion, or shorts.
If all else is normal, test the BCM/SCCM for internal faults.
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive, but the horn may not work, which could be a safety concern in emergency situations. Have it diagnosed soon.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on the root cause (e.g., clockspring replacement vs. module repair).