B1402 – Driver Power Window Down Switch Circuit Failure

The ODBII 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.

The severity of ODBII code B1402 is generally considered moderate.

Common Causes For: B1401 Driver Power Window One Touch Window Relay Circuit Short To Ground

• 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 misdiagnosis for B1402 Driver Power Window Down Switch Circuit Failure

• 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

Common Troubleshooting Steps

The OBD-II code B1402 indicates a problem with the driver power window down switch circuit. This code typically points to an issue with the switch itself, the wiring, or the power window motor. Here are some common troubleshooting steps to diagnose and potentially resolve the issue:

• Visual Inspection:
• Check the driver power window switch for any visible damage, such as cracks or corrosion.
• Inspect the wiring harness and connectors for signs of wear, fraying, or disconnection.
• Look for any signs of moisture or dirt that could affect the switch’s operation.
• Check Fuses:
• 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.
• Test the Switch:
• 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.
• Inspect the Power Window Motor:
• Test the power window motor by applying direct power to it. If the motor does not operate, it may be faulty and require replacement.
• Check for Ground Issues:
• Ensure that the ground connections for the power window circuit are secure and free of corrosion. A poor ground can cause circuit failures.
• 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.
• Check for Short Circuits:
• Inspect the wiring for any short circuits or open circuits that could be affecting the power window switch operation.
• Test the Body Control Module (BCM):
• If all other components check out, the issue may lie with the BCM. Testing or reprogramming the BCM may be necessary.
• Consult Wiring Diagrams:
• Refer to the vehicle’s wiring diagrams to trace the circuit and identify any potential issues in the wiring or connections.
• Professional Diagnosis:
• 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.