B1439 – Wiper Mode Select Switch Circuit Open

The ODBII code B1439 indicates a malfunction in the wiper mode select switch circuit, specifically that the circuit is open, meaning there is a break or disconnection in the electrical path.

The severity of ODBII code B1439 is generally considered moderate.

Common Causes For: B1438 Wiper Mode Select Switch Circuit Failure

• Faulty wiper mode select switch
• Open circuit in wiring harness
• Corroded or damaged connectors
• Short circuit in the circuit
• Faulty body control module (BCM)
• Poor ground connection

Common misdiagnosis for B1439 Wiper Mode Select Switch Circuit Open

• Faulty wiper motor
• Bad wiper relay
• Damaged wiring or connectors
• Malfunctioning body control module (BCM)
• Incorrectly installed or defective wiper switch
• Issues with the fuse or fuse box
• Problems with the windshield washer system

Common Troubleshooting Steps

The OBD-II code B1439 indicates an issue with the Wiper Mode Select Switch Circuit, specifically that there is an open circuit. Here are some common troubleshooting steps to diagnose and potentially resolve this issue:

• Check the Vehicle’s Manual: Refer to the vehicle’s service manual for specific information regarding the wiper mode select switch circuit, including wiring diagrams and component locations.
• Visual Inspection:
• Inspect the wiper mode select switch for any visible damage or wear.
• Check the wiring harness and connectors associated with the wiper mode select switch for signs of fraying, corrosion, or disconnection.
• Test the Wiper Mode Select Switch:
• Use a multimeter to test the resistance of the wiper mode select switch. Compare the readings to the specifications in the service manual.
• If the switch is faulty, it may need to be replaced.
• Check for Open Circuits:
• Use a multimeter to check for continuity in the wiring between the wiper mode select switch and the Body Control Module (BCM) or any other relevant control module.
• Look for any breaks in the wire or poor connections that could cause an open circuit.
• Inspect Related Components:
• Check other components in the wiper system, such as the wiper motor and relays, to ensure they are functioning correctly.
• Ensure that the fuses related to the wiper system are intact.
• 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.
• Clear the Code:
• After performing any repairs or replacements, clear the trouble code using an OBD-II scanner and take the vehicle for a test drive to see if the code returns.
• Consult a Professional:
• If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician for further diagnosis. By following these steps, you should be able to identify and resolve the issue related to the B1439 code.