B1734 – OBD-II DTC

OBD-II DTC B1734 – Mirror Driver Vertical Switch Circuit Open

DTC B1734 meaning

DTC B1734 refers to a diagnostic trouble code indicating an issue with the driver’s vertical switch circuit for the mirror adjustment. This code is triggered when the vehicle’s onboard diagnostic system detects an open circuit in the switch that controls the vertical movement of the driver’s side mirror. The open circuit can prevent the mirror from adjusting properly, affecting visibility and safety.

DTC B1734 symptoms

Common symptoms associated with DTC B1734 may include:

• The driver’s side mirror does not adjust vertically.
• Inability to control the mirror position using the switch.
• Other mirror functions may still operate normally.
• Warning lights may illuminate on the dashboard.

DTC B1734 causes

Several factors can lead to the triggering of DTC B1734, including:

• A faulty vertical switch in the driver’s side mirror control.
• Wiring issues, such as frayed or broken wires in the circuit.
• Corrosion or poor connections in the electrical connectors.
• Faulty mirror motor that may not respond to the switch input.
• Issues with the vehicle’s body control module (BCM) that processes the switch signals.

DTC B1734 seriousness

DTC B1734 is considered a moderate issue. While it may not immediately affect the vehicle’s drivability, it can compromise the driver’s ability to adjust the mirror for optimal visibility. This can lead to safety concerns, especially when changing lanes or merging. It is advisable to address this code promptly to ensure safe driving conditions.

How to diagnose DTC B1734

To diagnose DTC B1734, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the B1734 code.
2. Inspect the driver’s side mirror switch for physical damage or wear.
3. Check the wiring and connectors for signs of corrosion, fraying, or disconnection.
4. Test the vertical switch using a multimeter to ensure it is functioning correctly.
5. Examine the mirror motor for proper operation.
6. Check the body control module for any related fault codes or issues.

How to fix DTC B1734 step-by-step instructions

To fix DTC B1734, follow these steps:

1. Disconnect the vehicle’s battery to ensure safety while working on electrical components.
2. Inspect and repair or replace any damaged wiring or connectors related to the mirror switch.
3. If the vertical switch is faulty, replace it with a new one.
4. Test the mirror motor to ensure it operates correctly replace if necessary.
5. Reconnect the battery and clear the DTC using an OBD-II scanner.
6. Test the mirror adjustment functions to confirm the issue is resolved.

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