WOMS
B code body Medium severity

B2251 Parklamp Output Relay Driver Circuit Failure

The OBD2 code B2251 indicates a malfunction in the park lamp output relay driver circuit, which may affect the operation of the vehicle's parking lights

Definition

The OBD2 code B2251 indicates a malfunction in the park lamp output relay driver circuit, which may affect the operation of the vehicle's parking lights

Common causes

  • Faulty park lamp output relay
  • Short circuit in the wiring harness
  • Open circuit in the wiring harness
  • Corroded or damaged connectors
  • Faulty body control module (BCM)
  • Blown fuse
  • Grounding issues
  • Faulty park lamp bulbs

Common misdiagnoses

  • Faulty park lamp bulbs
  • Bad park lamp sockets
  • Wiring issues or shorts in the circuit
  • Faulty body control module (BCM)
  • Incorrectly diagnosed headlight or taillight issues
  • Malfunctioning switch or relay unrelated to the park lamp circuit
  • Battery or charging system problems affecting electrical components

Troubleshooting steps

  1. 1. Check the Vehicle's Manual

    Refer to the vehicle's service manual for specific information related to the B2251 code, including wiring diagrams and component locations

  2. 2. Visual Inspection

    Inspect the wiring and connectors related to the park lamp output relay. Look for signs of damage, corrosion, or loose connections

  3. 3. Check the park lamp bulbs to ensure they are functioning properly and are not burnt out

  4. 4. Scan Tool Diagnosis

    Use an OBD-II scanner to confirm the presence of the B2251 code. Check for any additional codes that may provide more context

  5. 5. Clear the code and see if it returns after a short drive. This can help determine if the issue is intermittent

  6. 6. Test the Parklamp Output Relay

    Locate the park lamp output relay and test it for proper operation. You can do this by

  7. 7. Swapping it with a similar relay (if available) to see if the problem persists

  8. 8. Using a multimeter to check for continuity and proper voltage at the relay terminals

  9. 9. Check the Circuit

    Use a multimeter to test the voltage and ground at the relay and the associated wiring. Ensure that the relay is receiving the correct voltage from the control module

  10. 10. Inspect the circuit for shorts to ground or open circuits

  11. 11. Inspect the Control Module

    If the relay and wiring are functioning correctly, the issue may lie within the control module (BCM or PCM). Check for any software updates or known issues with the module

  12. 12. If possible, perform a reset or reprogramming of the control module

  13. 13. Check for Ground Issues

    Ensure that the ground connections for the park lamp circuit are secure and free of corrosion. Poor grounding can lead to circuit failures

  14. 14. Test the Park Lamp Switch

    Inspect and test the park lamp switch for proper operation. A faulty switch can cause the relay to fail to activate

  15. 15. Consult Technical Service Bulletins (TSBs)

    Look for any TSBs related to the B2251 code for your specific vehicle make and model. Manufacturers may have issued guidance on common issues and fixes

  16. 16. Professional Diagnosis

    If the issue persists after performing these steps, consider seeking help from a professional mechanic or dealership. They may have specialized tools and knowledge to diagnose the problem more effectively.Conclusion By following these troubleshooting steps, you should be able to identify the cause of the B2251 code and take appropriate action to resolve the issue. Always ensure safety precautions are taken when working on vehicle electrical systems