WOMS
B code body Medium severity

B1687 Lamp Dome Input Circuit Short To Battery

The OBD2 code B1687 indicates a short circuit in the dome lamp input circuit, meaning that the circuit is receiving voltage directly from the battery instead of functioning normally

Definition

The OBD2 code B1687 indicates a short circuit in the dome lamp input circuit, meaning that the circuit is receiving voltage directly from the battery instead of functioning normally

Common causes

  • Shorted wiring or connectors in the dome lamp circuit
  • Faulty dome lamp switch
  • Defective body control module (BCM)
  • Corroded or damaged ground connections
  • Malfunctioning door switches
  • Incorrectly installed or damaged aftermarket accessories

Common misdiagnoses

  • Faulty dome light switch
  • Shorted wiring harness
  • Defective body control module (BCM)
  • Malfunctioning door switch
  • Incorrectly installed or damaged bulbs
  • Grounding issues
  • Faulty fuse or relay
  • Corroded connectors

Troubleshooting steps

  1. 1. Check the Vehicle's Manual

    Refer to the vehicle's service manual for specific information about the dome light circuit and wiring diagrams

  2. 2. Visual Inspection

    Inspect the wiring and connectors associated with the dome light circuit for any signs of damage, corrosion, or loose connections

  3. 3. Look for any frayed wires or exposed conductors that could be causing a short to battery

  4. 4. Check the Dome Light Bulb

    Remove the dome light bulb and inspect it for any signs of damage or corrosion

  5. 5. Replace the bulb if necessary and check if the code persists

  6. 6. Test the Dome Light Switch

    Check the operation of the dome light switch (if applicable). Ensure it is functioning correctly and not stuck in the "on" position

  7. 7. Test the switch for continuity using a multimeter

  8. 8. Inspect the Ground Connection

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

  9. 9. Test the ground wire for continuity to ensure it is properly grounded

  10. 10. Check for Short Circuits

    Use a multimeter to check for continuity between the dome light circuit and the battery positive terminal. A reading indicates a short circuit

  11. 11. Inspect the wiring harness for any areas where the wires may be pinched or damaged

  12. 12. Scan for Additional Codes

    Use an OBD-II scanner to check for any additional trouble codes that may provide more context for the issue

  13. 13. Address any other codes that may be present, as they could be related

  14. 14. Clear the Code

    After performing the above checks and repairs, clear the trouble code using an OBD-II scanner

  15. 15. Take the vehicle for a test drive to see if the code returns

  16. 16. Consult a Professional

    If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or an automotive electrician for further diagnosis

  17. 17. Check for Technical Service Bulletins (TSBs)

    Look for any TSBs related to the dome light circuit for your specific vehicle make and model, as there may be known issues or fixes. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the B1687 code