B1783 – OBD-II DTC

OBD-II DTC B1783 – Mirror Passenger Up Circuit Open

DTC B1783 meaning

DTC B1783 refers to a diagnostic trouble code indicating an open circuit in the passenger side mirror’s up control circuit. This code is part of the On-Board Diagnostics II (OBD-II) system, which monitors various vehicle components and systems for faults. When the vehicle’s computer detects that the signal from the passenger mirror’s up control switch is not reaching the mirror actuator, it triggers this code.

DTC B1783 symptoms

Common symptoms associated with DTC B1783 may include:

• Passenger side mirror not adjusting up
• Mirror control switch not functioning properly
• Other mirror functions may still work
• Warning lights on the dashboard related to the mirror system

DTC B1783 causes

Several factors can lead to the triggering of DTC B1783, including:

• Faulty mirror control switch
• Damaged wiring or connectors in the mirror circuit
• Defective mirror actuator
• Corrosion or poor connections in the electrical system
• Issues with the vehicle’s body control module (BCM)

DTC B1783 seriousness

DTC B1783 is generally considered a moderate issue. While it may not affect the vehicle’s overall drivability, it can hinder the driver’s ability to adjust the passenger side mirror, which is important for safe driving. Ignoring this code may lead to further electrical issues or complications in the mirror system.

How to diagnose DTC B1783

To diagnose DTC B1783, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the B1783 code.
2. Inspect the mirror control switch for any visible damage or wear.
3. Check the wiring and connectors leading to the passenger side mirror for signs of damage or corrosion.
4. Test the mirror actuator to ensure it is functioning correctly.
5. Examine the body control module for any faults or issues.
6. Clear the code and perform a function test to see if the issue persists.

How to fix DTC B1783 step-by-step instructions

To fix DTC B1783, follow these steps:

1. Disconnect the vehicle’s battery to ensure safety while working on electrical components.
2. Inspect and replace the mirror control switch if it is found to be faulty.
3. Repair or replace any damaged wiring or connectors in the mirror circuit.
4. Test and replace the mirror actuator if it is not functioning properly.
5. Check the body control module for any faults and replace it if necessary.
6. Reconnect the battery and clear the DTC using an OBD-II scanner.
7. Test the passenger side mirror to ensure all functions are working correctly.

How to erase DTC B1783

To erase DTC B1783, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the vehicle’s ignition without starting the engine.
3. Navigate to the “Erase Codes” or “Clear DTCs” option on the scanner.
4. Confirm the action to erase the trouble codes.
5. Disconnect the scanner and start the vehicle to check if the code returns.

Recommended tools for OBD-II diagnostics

Explore our expert picks: The Best OBD2 Scanners for 2025

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.