WOMS
B code body Medium severity

B1399 Driver Power Window One Touch Window Relay Circuit Open

The OBD2 code B1399 indicates a malfunction in the driver power window one-touch window relay circuit, specifically that the circuit is open, which means there is a break or fault preventing proper operation of the...

Definition

The OBD2 code B1399 indicates a malfunction in the driver power window one-touch window relay circuit, specifically that the circuit is open, which means there is a break or fault preventing proper operation of the one-touch feature for the driver's power window

Common causes

  • Faulty one-touch window relay
  • Open or shorted wiring in the relay circuit
  • Bad connection or corroded terminals
  • Faulty power window switch
  • Malfunctioning body control module (BCM)
  • Blown fuse related to the power window system
  • Ground connection issues

Common misdiagnoses

  • Faulty window switch
  • Defective power window motor
  • Wiring issues or shorts in the harness
  • Malfunctioning body control module (BCM)
  • Incorrectly installed or damaged window regulator
  • Battery or charging system problems
  • Faulty relay or fuse related to the power window system

Troubleshooting steps

  1. 1. Check the Vehicle's Battery

    Ensure the battery is fully charged and in good condition. A weak battery can cause various electrical issues

  2. 2. Inspect Fuses

    Locate the fuse box and check for any blown fuses related to the power windows or the one-touch window feature. Replace any blown fuses

  3. 3. Examine Wiring and Connectors

    Inspect the wiring harness and connectors associated with the power window system. Look for signs of damage, corrosion, or loose connections

  4. 4. Pay special attention to the wiring leading to the driver’s side window switch and the relay

  5. 5. Test the One-Touch Window Switch

    Use a multimeter to test the functionality of the one-touch window switch. Ensure it is providing the correct voltage and that it is not stuck or malfunctioning

  6. 6. Check the Relay

    Locate the relay for the power window system and test it. You can swap it with a similar relay in the fuse box to see if the problem persists

  7. 7. If the relay is faulty, replace it

  8. 8. Inspect the Power Window Motor

    Test the power window motor to ensure it is functioning correctly. If the motor is not working, it may need to be replaced

  9. 9. 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

  10. 10. Check for Ground Issues

    Ensure that the ground connections for the power window system are secure and free of corrosion. A poor ground can lead to circuit issues

  11. 11. Look for Short Circuits

    Inspect the circuit for any signs of short circuits that could be causing the relay circuit to open

  12. 12. Consult Wiring Diagrams

    Refer to the vehicle’s service manual for wiring diagrams to understand the circuit better and identify any potential issues.1

  13. 13. Perform a System Reset

    Sometimes, resetting the vehicle’s computer can clear temporary faults. Disconnect the battery for a few minutes and reconnect it.1

  14. 14. Professional Diagnosis

    If the issue persists after performing these steps, consider seeking help from a professional mechanic or an automotive technician who can perform more advanced diagnostics. By following these steps, you should be able to identify and potentially resolve the issue related to the B1399 code. Always ensure safety precautions are taken when working with electrical systems in vehicles