WOMS
B code body Medium severity

B1873 Turn Signal / Hazard Power Feed Circuit Short To Ground

The OBD2 code B1873 indicates a short circuit to ground in the power feed circuit for the turn signal or hazard lights, which can cause the lights to malfunction

Definition

The OBD2 code B1873 indicates a short circuit to ground in the power feed circuit for the turn signal or hazard lights, which can cause the lights to malfunction

Common causes

  • Damaged wiring or insulation
  • Faulty turn signal switch
  • Shorted turn signal relay
  • Corroded connectors
  • Faulty hazard switch
  • Grounding issues
  • Water intrusion or moisture in electrical components
  • Aftermarket modifications or installations

Common misdiagnoses

  • Faulty turn signal switch
  • Defective hazard switch
  • Shorted wiring harness
  • Bad ground connection
  • Malfunctioning body control module (BCM)
  • Incorrectly installed aftermarket accessories
  • Faulty relay
  • Damaged connectors or terminals
  • Issues with the lighting control module
  • Battery or charging system problems

Troubleshooting steps

  1. 1. Verify the Code

    Use an OBD-II scanner to confirm the presence of the B1873 code

  2. 2. Check for any additional codes that may provide more context or related issues

  3. 3. Inspect the Wiring and Connectors

    Visual Inspection: Check the wiring harnesses and connectors related to the turn signal and hazard circuits for any signs of damage, fraying, or corrosion

  4. 4. Ground Connections

    Ensure that all ground connections are secure and free of corrosion

  5. 5. Check the Turn Signal and Hazard Switch

    Test the turn signal and hazard switch for proper operation. A faulty switch can cause a short circuit

  6. 6. If possible, disconnect the switch and see if the code persists

  7. 7. Examine the Fuses

    Check the fuses related to the turn signal and hazard lights. A blown fuse can indicate a short circuit

  8. 8. Replace any blown fuses and see if the issue resolves

  9. 9. Test for Short Circuits

    Use a multimeter to check for continuity in the wiring. Look for any shorts to ground in the turn signal and hazard circuits

  10. 10. Disconnect components one at a time (like bulbs, relays, etc.) to isolate the short

  11. 11. Inspect the Turn Signal and Hazard Light Bulbs

    Check the bulbs for any signs of damage or improper installation. A shorted bulb can cause this code

  12. 12. Replace any faulty bulbs and retest

  13. 13. Check the Relay

    If applicable, test the turn signal and hazard light relay. A malfunctioning relay can cause issues in the circuit

  14. 14. Swap with a known good relay if possible to see if the problem resolves

  15. 15. Scan for Additional Codes

    After performing repairs, clear the codes and perform a test drive to see if the B1873 code returns

  16. 16. Monitor the system for any new codes that may appear

  17. 17. Consult Wiring Diagrams

    Refer to the vehicle’s wiring diagrams to understand the circuit layout and identify any potential problem areas

  18. 18. Professional Help

    If the issue persists after following these steps, consider seeking help from a professional mechanic or automotive technician who has experience with electrical systems.Conclusion By following these troubleshooting steps, you should be able to identify and resolve the issue causing the B1873 code. Always ensure safety precautions are taken when working with electrical systems in vehicles