WOMS
B code body Medium severity

B1402 Driver Power Window Down Switch Circuit Failure

The OBD2 code B1402 indicates a malfunction in the driver power window down switch circuit, suggesting a failure in the switch or its wiring that affects the operation of the driver's side power window

Definition

The OBD2 code B1402 indicates a malfunction in the driver power window down switch circuit, suggesting a failure in the switch or its wiring that affects the operation of the driver's side power window

Common causes

  • Faulty power window switch
  • Damaged wiring or connectors
  • Short circuit in the circuit
  • Failed power window motor
  • Blown fuse
  • Ground connection issues
  • Malfunctioning body control module (BCM)

Common misdiagnoses

  • Faulty power window motor
  • Bad window regulator
  • Wiring issues or shorts in the harness
  • Defective body control module (BCM)
  • Malfunctioning driver door module
  • Issues with the fuse or relay
  • Problems with the power window switch itself

Troubleshooting steps

  1. 1. Visual Inspection

  2. 2. Check the driver power window switch for any visible damage, such as cracks or corrosion

  3. 3. Inspect the wiring harness and connectors for signs of wear, fraying, or disconnection

  4. 4. Look for any signs of moisture or dirt that could affect the switch's operation

  5. 5. Check Fuses

  6. 6. Locate the fuse box and check the fuse related to the power windows. If the fuse is blown, replace it and see if the issue persists

  7. 7. Test the Switch

  8. 8. Use a multimeter to test the continuity of the driver power window down switch. If the switch does not show continuity when pressed, it may need to be replaced

  9. 9. Inspect the Power Window Motor

  10. 10. Test the power window motor by applying direct power to it. If the motor does not operate, it may be faulty and require replacement

  11. 11. Check for Ground Issues

  12. 12. Ensure that the ground connections for the power window circuit are secure and free of corrosion. A poor ground can cause circuit failures

  13. 13. Scan for Additional Codes

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

  15. 15. Check for Short Circuits

  16. 16. Inspect the wiring for any short circuits or open circuits that could be affecting the power window switch operation

  17. 17. Test the Body Control Module (BCM)

  18. 18. If all other components check out, the issue may lie with the BCM. Testing or reprogramming the BCM may be necessary

  19. 19. Consult Wiring Diagrams

  20. 20. Refer to the vehicle’s wiring diagrams to trace the circuit and identify any potential issues in the wiring or connections

  21. 21. Professional Diagnosis

  22. 22. If the problem persists after performing these steps, consider seeking help from a professional mechanic or automotive technician who can perform more advanced diagnostics. By following these steps, you should be able to identify the cause of the B1402 code and take appropriate action to resolve the issue