B1742 – Mirror Passenger Vertical Switch Circuit Open

The ODBII code B1742 indicates an open circuit in the passenger side mirror’s vertical switch, meaning there is a malfunction preventing the switch from functioning properly.

The severity of ODBII code B1742 is generally considered low.

Common Causes For: B1741 Mirror Passenger Vertical Switch Circuit Failure

• Faulty passenger mirror vertical switch
• Open circuit in the wiring harness
• Corroded or damaged connectors
• Faulty body control module (BCM)
• Blown fuse related to the mirror system
• Ground connection issues

Common misdiagnosis for B1742 Mirror Passenger Vertical Switch Circuit Open

• Faulty passenger side mirror motor
• Wiring issues or shorts in the mirror circuit
• Defective mirror switch assembly
• Body control module (BCM) malfunction
• Incorrectly diagnosed window switch problems
• Issues with the vehicle’s electrical system or grounds
• Faulty connectors or terminals related to the mirror circuit

Common Troubleshooting Steps

The OBD-II code B1742 indicates a problem with the passenger side mirror’s vertical switch circuit, specifically that the circuit is open. Here are some common troubleshooting steps to diagnose and potentially resolve this issue:

• Check for Additional Codes: Use an OBD-II scanner to check for any other related trouble codes that may provide more context or indicate other issues.
• Inspect the Wiring and Connectors:
• Visually inspect the wiring harness and connectors associated with the passenger side mirror. Look for any signs of damage, fraying, corrosion, or loose connections.
• Pay special attention to the wiring that runs through the door, as this area is prone to wear and tear.
• Test the Switch:
• Remove the switch from the door panel and test it with a multimeter. Check for continuity when the switch is activated. If the switch is faulty, it may need to be replaced.
• Check the Mirror Motor:
• If the switch tests good, the issue may lie with the mirror motor itself. Test the motor for proper operation by applying direct power to it (if safe to do so) to see if it responds.
• Inspect the Ground Connection:
• Ensure that the ground connection for the mirror and switch is secure and free of corrosion. A poor ground can cause circuit issues.
• Check for Short Circuits:
• Use a multimeter to check for any short circuits in the wiring. This can help identify if there is a short to ground or another wire.
• Look for Water Intrusion:
• Check for any signs of water intrusion in the door or around the mirror assembly, as moisture can cause electrical issues.
• Consult Wiring Diagrams:
• Refer to the vehicle’s wiring diagrams to understand the circuit layout and identify any other components that may be involved in the circuit.
• Perform a System Reset:
• After addressing any issues found, clear the trouble codes using the OBD-II scanner and see if the code returns after a test drive.
• Seek Professional Help:
• If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or an automotive electrician for further diagnosis. By following these steps, you should be able to identify and resolve the issue related to the B1742 code.