WOMS
B code body Medium severity

B1799 Lamp Turn Signal Front Output Circuit Open

The OBD2 code B1799 indicates that there is an open circuit in the front turn signal output, meaning the vehicle's system is not detecting a proper connection or signal from the front turn signal lamp

Definition

The OBD2 code B1799 indicates that there is an open circuit in the front turn signal output, meaning the vehicle's system is not detecting a proper connection or signal from the front turn signal lamp

Common causes

  • Open circuit in the turn signal wiring
  • Faulty turn signal bulb
  • Defective turn signal relay
  • Poor ground connection
  • Damaged or corroded connectors
  • Faulty body control module (BCM)
  • Short circuit in the wiring harness

Common misdiagnoses

  • Faulty turn signal switch
  • Bad wiring or connections
  • Defective body control module (BCM)
  • Malfunctioning relay
  • Burnt-out bulbs
  • Incorrectly installed bulbs
  • Grounding issues
  • Faulty fuse

Troubleshooting steps

  1. 1. Check the Vehicle's Manual

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

  2. 2. Visual Inspection

  3. 3. Inspect the front turn signal bulbs to ensure they are not burned out or damaged

  4. 4. Check the bulb sockets for corrosion or damage

  5. 5. Look for any visible damage to the wiring harness, connectors, or terminals related to the turn signal circuit

  6. 6. Test the Bulbs

  7. 7. Remove the turn signal bulbs and test them with a multimeter to ensure they are functioning properly

  8. 8. Replace any faulty bulbs

  9. 9. Check the Fuses

  10. 10. Locate the fuse box and check for any blown fuses related to the turn signal circuit. Replace any blown fuses

  11. 11. Inspect the Wiring and Connectors

  12. 12. Follow the wiring from the turn signal bulbs back to the control module. Look for any signs of wear, fraying, or disconnection

  13. 13. Ensure that all connectors are securely attached and free of corrosion

  14. 14. Test the Turn Signal Relay

  15. 15. If applicable, test the turn signal relay to ensure it is functioning correctly. You can swap it with a similar relay in the fuse box to see if the problem persists

  16. 16. Check for Ground Issues

  17. 17. Ensure that the ground connection for the turn signal circuit is secure and free of corrosion. A poor ground can cause an open circuit

  18. 18. Scan for Additional Codes

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

  20. 20. Perform a Continuity Test

  21. 21. Use a multimeter to perform a continuity test on the wiring from the turn signal switch to the bulbs. This will help identify any breaks in the circuit

  22. 22. Inspect the Turn Signal Switch

  23. 23. If all other components check out, the turn signal switch itself may be faulty. Test or replace the switch if necessary. 1

  24. 24. Clear the Code and Test Drive

  25. 25. After performing repairs, clear the trouble code using an OBD-II scanner and take the vehicle for a test drive to see if the code returns. If you are not comfortable performing these steps or if the issue persists after troubleshooting, it may be best to consult a professional mechanic for further diagnosis and repair