WOMS
B code body High severity

B2249 Head Lamp Relay Coil Short to Battery

The OBD2 code B2249 indicates a short circuit in the headlamp relay coil, meaning the relay is receiving constant power from the battery instead of being controlled by the vehicle's electrical system

Definition

The OBD2 code B2249 indicates a short circuit in the headlamp relay coil, meaning the relay is receiving constant power from the battery instead of being controlled by the vehicle's electrical system

Common causes

  • Shorted headlamp relay coil
  • Damaged wiring or connectors
  • Faulty headlamp relay
  • Corroded electrical connections
  • Malfunctioning body control module (BCM)
  • Incorrectly installed aftermarket components
  • Grounding issues

Common misdiagnoses

  • Faulty headlamp relay
  • Shorted wiring harness
  • Defective headlight switch
  • Malfunctioning body control module (BCM)
  • Bad ground connection
  • Incorrectly installed aftermarket lighting
  • Faulty fuse or fuse box issues

Troubleshooting steps

  1. 1. Understand the Code

    B2249 typically indicates that the headlamp relay coil is shorted to battery voltage. This means that the relay is receiving constant power, which can cause the headlights to stay on or malfunction

  2. 2. Visual Inspection

    Check Wiring and Connectors: Inspect the wiring harness and connectors related to the headlamp relay for any signs of damage, fraying, or corrosion

  3. 3. Look for Shorts

    Check for any exposed wires that may be touching the chassis or other components, which could cause a short circuit

  4. 4. Test the Relay

    Remove the Relay: Take out the headlamp relay from the fuse box

  5. 5. Check for Continuity

    Use a multimeter to check for continuity across the relay terminals. If there is continuity when the relay is not energized, the relay may be faulty

  6. 6. Test Relay Operation

    If possible, test the relay by applying power to it and checking if it operates correctly

  7. 7. Inspect the Headlamp Circuit

    Check the Headlamp Bulbs: Ensure that the headlamp bulbs are not shorted. A shorted bulb can cause the relay to malfunction

  8. 8. Examine the Ground

    Ensure that the ground connection for the headlamp circuit is secure and free of corrosion

  9. 9. Check for Faulty Components

    Inspect the Body Control Module (BCM): The BCM controls the headlamp relay. If it is malfunctioning, it may send incorrect signals to the relay

  10. 10. Look for Other Faulty Relays

    Sometimes, other relays in the same circuit can cause issues. Check for any other related codes or symptoms

  11. 11. Scan for Additional Codes

    Use an OBD-II scanner to check for any additional trouble codes that may provide more context or indicate related issues

  12. 12. Repair or Replace Components

    Repair Wiring: If you find damaged wiring or connectors, repair or replace them as necessary

  13. 13. Replace the Relay

    If the relay is found to be faulty, replace it with a new one

  14. 14. Replace the BCM

    If the BCM is determined to be the issue, it may need to be reprogrammed or replaced

  15. 15. Clear Codes and Test Drive

    After making repairs, clear the trouble codes using the OBD-II scanner

  16. 16. Take the vehicle for a test drive to see if the code returns and to ensure that the headlights function correctly

  17. 17. Consult a Professional

    If the issue persists after following these steps, it may be best to consult a professional mechanic or an automotive electrician for further diagnosis. By following these steps, you should be able to identify and resolve the issue related to the B2249 code. Always ensure safety precautions are taken when working with electrical components in a vehicle