What Does B1897 Mean?
This code indicates the Body Control Module (BCM) has detected an electrical fault in the horn switch circuit. The BCM monitors the horn switch input and has identified either an open circuit, short circuit, or abnormal resistance that prevents proper horn operation. This is a manufacturer-specific body control code that flags communication or signal issues between the horn switch (typically in the steering wheel) and the BCM.
Common Causes
45%
Faulty horn switch or worn clock spring (spiral cable) in steering column
30%
Damaged, corroded, or disconnected wiring harness between horn switch and BCM
15%
Faulty Body Control Module (BCM) internal circuit failure
10%
Blown fuse or relay associated with horn circuit power supply
Diagnostic Steps
1
Step 1: Perform visual inspection of steering wheel horn switch area and steering column for obvious damage, disconnected connectors, or signs of water intrusion. Check for proper seating of all connectors related to horn circuit.
2
Step 2: Using a multimeter, test horn circuit fuse and relay for continuity and proper voltage supply (typically 12V). Check ground connections at BCM and steering column for resistance (should be less than 1 ohm to chassis ground).
3
Step 3: Access horn switch connector in steering wheel (may require removing airbag module following proper safety procedures). Measure resistance across horn switch terminals while pressing horn button - should show near 0 ohms when pressed, infinite resistance when released.
4
Step 4: If horn switch tests good, test clock spring continuity by measuring resistance through the spiral cable assembly while rotating steering wheel full lock to lock. Any open circuit or intermittent reading indicates clock spring failure.
5
Step 5: Backprobe BCM connector at horn switch input terminal and verify voltage/ground signals match manufacturer specifications. If no signal present at switch but present at BCM, trace and repair wiring harness between components.
6
Step 6: Clear codes and perform horn function test. Monitor live data for horn switch status while pressing button to verify BCM recognizes input. If all components test good but code returns, suspect internal BCM failure requiring replacement.
Estimated Repair Cost
$75 - $650
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an electrical fault in the horn switch circuit. The BCM monitors the horn switch input and has identified either an open circuit, short circuit, or abnormal resistance that prevents proper horn operation. This is a manufacturer-specific ...
The most common cause of B1897 (Horn Switch Circuit Failure) is: Faulty horn switch or worn clock spring (spiral cable) in steering column
Typical repair costs for B1897 range from $75 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is safe to drive but the horn will likely be inoperative, which removes an important safety warning device for other drivers and pedestrians. Repair should be completed promptly to restore full safety equipment functionality, and may be required to pass vehicle inspection in some jurisdictions.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1897 to identify the root cause.
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Quick Info
Category
Body
System
Body Control System
Difficulty
Type
Manufacturer
Recommended Tools
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