B1734 – Mirror Driver Vertical Switch Circuit Open

The ODBII code B1734 indicates a malfunction in the vertical switch circuit of the mirror driver, specifically that the circuit is open, meaning there is a break in the electrical connection preventing proper operation.

The severity of ODBII code B1734 is generally considered moderate.

Common Causes For: B1733 Mirror Driver Vertical Switch Circuit Failure

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

Common misdiagnosis for B1734 Mirror Driver Vertical Switch Circuit Open

• Faulty mirror switch
• Wiring issues
• Defective mirror motor
• Body control module (BCM) failure
• Short circuit in the mirror circuit
• Poor ground connection
• Faulty door module

Common Troubleshooting Steps

The OBD-II code B1734 refers to a problem with the mirror driver vertical switch circuit, indicating that there is an open circuit in the system. 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. This can provide more context and help identify if there are other issues present.
• Inspect the Wiring and Connectors:
• Visually inspect the wiring harness and connectors associated with the mirror switch and the mirror itself. Look for any signs of damage, corrosion, or loose connections.
• Pay special attention to the wiring that runs to the mirror and the switch, as these are common areas for wear and tear.
• Test the Mirror Switch:
• Remove the mirror switch from the vehicle and test it with a multimeter. Check for continuity in the switch when it is activated. If the switch is faulty, it may need to be replaced.
• Check the Mirror Motor:
• If the switch tests good, check the mirror motor itself. You can do this by applying direct power to the motor to see if it operates. If it does not, the motor may be faulty and require replacement.
• Inspect the Ground Connections:
• Ensure that all ground connections related to the mirror and switch are secure and free of corrosion. A poor ground can cause various electrical 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 that is causing the open circuit condition.
• Examine the Body Control Module (BCM):
• If all other components check out, the issue may lie within the Body Control Module. Inspect the BCM for any signs of damage or failure. In some cases, reprogramming or replacing the BCM may be necessary.
• Clear the Codes and Test Drive:
• After performing the necessary repairs, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns.
• Consult a Professional:
• If you are unable to resolve the issue after these steps, it may be best to consult a professional mechanic or an automotive electrician who can perform more advanced diagnostics. By following these steps, you should be able to identify and resolve the issue related to the B1734 code.