B1840 – Wiper Front Power Circuit Failure

The ODBII code B1840 indicates a failure in the front wiper power circuit, which may involve issues with the wiper motor, wiring, or related components.

The severity of ODBII code B1840 is moderate.

Common Causes For: B1839 Wiper Rear Motor Circuit Failure

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

Common misdiagnosis for B1840 Wiper Front Power Circuit Failure

• Faulty wiper motor
• Bad wiper switch
• Wiring issues or shorts
• Blown fuses
• Faulty body control module (BCM)
• Corroded connectors
• Incorrectly installed or damaged wiper linkage

Common Troubleshooting Steps

The OBD-II code B1840 indicates a “Wiper Front Power Circuit Failure.” This code typically relates to issues with the front windshield wiper system, which can include problems with the wiper motor, wiring, or related components. Here are some common troubleshooting steps to diagnose and resolve the issue:

• Check the Wiper Motor:: **Visual Inspection:** Look for any physical damage to the wiper motor.
• **Test the Motor:** Use a multimeter to check for power and ground at the wiper motor connector. If there is no power, the issue may be upstream.
• Inspect Wiring and Connectors:: **Wiring Inspection:** Check the wiring harness for any signs of wear, fraying, or corrosion. Pay special attention to connectors and terminals.
• **Connector Check:** Ensure that all connectors are securely attached and free of corrosion.
• Examine the Wiper Switch:: **Functionality Test:** Test the wiper switch for proper operation. A faulty switch can prevent the wipers from functioning correctly.
• **Continuity Test:** Use a multimeter to check for continuity in the switch when it is activated.
• Check Fuses:: **Fuse Inspection:** Locate the fuse for the wiper system in the fuse box and check if it is blown. Replace it if necessary.
• **Fuse Circuit:** If the fuse is blown, investigate the circuit for shorts or overloads.
• Test the Relay:: **Relay Functionality:** If your vehicle has a relay for the wiper system, test it to ensure it is functioning properly. Swap it with a similar relay if available to see if that resolves the issue.
• Scan for Additional Codes:: **OBD-II Scanner:** Use an OBD-II scanner to check for any additional trouble codes that may provide more context or indicate related issues.
• Inspect the Wiper Linkage:: **Mechanical Inspection:** Check the wiper linkage for any binding or damage that could prevent the wipers from moving.
• Check for Ground Issues:: **Ground Connections:** Ensure that all ground connections related to the wiper system are clean and secure.
• Consult Wiring Diagrams:: **Wiring Diagrams:** Refer to the vehicle’s service manual for wiring diagrams to trace the circuit and identify any potential issues.
• Professional Diagnosis:: If the issue persists after performing these checks, consider seeking help from a professional mechanic who can perform more advanced diagnostics.Conclusion: By following these troubleshooting steps, you should be able to identify the cause of the B1840 code and take appropriate action to resolve the issue. Always remember to disconnect the battery before working on electrical components to avoid any accidental shorts or shocks.