B1839 – Wiper Rear Motor Circuit Failure

The ODBII code B1839 indicates a malfunction in the rear wiper motor circuit, suggesting a failure in the electrical system or components related to the rear wiper operation.

The severity of ODBII code B1839 is generally considered moderate.

Common Causes For: B1838 Battery Saver Power Relay Circuit Failure

• Faulty rear wiper motor
• Damaged wiring or connectors
• Blown fuse
• Faulty wiper switch
• Poor ground connection
• Corroded terminals
• Short circuit in the circuit
• Malfunctioning body control module (BCM)

Common misdiagnosis for B1839 Wiper Rear Motor Circuit Failure

• Faulty rear wiper switch
• Wiring issues or shorts in the circuit
• Defective rear wiper motor
• Blown fuse related to the rear wiper system
• Malfunctioning body control module (BCM)
• Incorrectly installed or damaged connectors
• Issues with the front wiper system affecting the rear wiper operation

Common Troubleshooting Steps

The OBD-II code B1839 indicates a “Wiper Rear Motor Circuit Failure.” This code typically relates to issues with the rear windshield wiper motor or its associated circuitry. Here are some common troubleshooting steps to diagnose and potentially resolve the issue:

• Check the Fuse:: Locate the fuse box and check the fuse associated with the rear wiper motor. If the fuse is blown, replace it and see if the problem persists.
• Inspect Wiring and Connectors:: Examine the wiring harness and connectors leading to the rear wiper motor for any signs of damage, corrosion, or loose connections. Repair or replace any damaged components.
• Test the Rear Wiper Motor:: Disconnect the rear wiper motor from the wiring harness and test it directly with a power source to see if it operates. If it does not work when powered directly, the motor may be faulty and need replacement.
• Check the Switch:: Test the rear wiper switch on the dashboard to ensure it is functioning correctly. A faulty switch can prevent the motor from receiving power.
• Inspect the Ground Connection:: Ensure that the ground connection for the rear wiper motor is secure and free of corrosion. A poor ground can lead to circuit failure.
• 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 signs of short circuits or grounding issues that could affect the rear wiper motor circuit.
• Consult Wiring Diagrams:: Refer to the vehicle’s service manual for wiring diagrams to understand the circuit better and identify any potential issues.
• Perform a Voltage Drop Test:: Use a multimeter to perform a voltage drop test on the circuit to ensure that the motor is receiving the correct voltage when the switch is activated.
• Professional Diagnosis:**
• If the issue persists after performing these steps, consider seeking help from a professional mechanic or technician who can perform more advanced diagnostics. By following these steps, you should be able to identify the cause of the B1839 code and take appropriate action to resolve the issue.