B1865 – OBD-II DTC

OBD-II DTC B1865 – Battery Power Supply ECU Circuit Open

DTC B1865 meaning

DTC B1865 refers to a diagnostic trouble code indicating an open circuit in the battery power supply ECU circuit. This code is specific to the vehicle’s body control module (BCM) and is related to the power supply that is necessary for the proper functioning of various electronic components within the vehicle.

DTC B1865 symptoms

Common symptoms associated with DTC B1865 may include:

• Malfunctioning electronic components
• Warning lights on the dashboard
• Inconsistent operation of power windows or locks
• Failure of the vehicle’s audio system
• Issues with the vehicle’s lighting systems

DTC B1865 causes

The causes of DTC B1865 can vary, but typical reasons include:

• Open or damaged wiring in the battery power supply circuit
• Faulty connectors or terminals
• Defective body control module (BCM)
• Corrosion or poor connections in the electrical system
• Battery issues, such as low voltage or failure

DTC B1865 seriousness

DTC B1865 is considered a moderate to serious issue. While it may not immediately affect the drivability of the vehicle, it can lead to further electrical problems if not addressed. Ignoring this code can result in the failure of critical electronic systems, which may compromise safety and functionality.

How to diagnose DTC B1865

To diagnose DTC B1865, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the DTC.
2. Inspect the battery and ensure it is fully charged and in good condition.
3. Check the wiring and connectors related to the battery power supply circuit for any signs of damage or corrosion.
4. Test the continuity of the circuit to identify any open connections.
5. Examine the body control module for any faults or issues.

How to fix DTC B1865 step-by-step instructions

To fix DTC B1865, follow these steps:

1. Repair or replace any damaged wiring or connectors in the battery power supply circuit.
2. Clean any corroded terminals and ensure all connections are secure.
3. Test the body control module and replace it if it is found to be defective.
4. Ensure the battery is functioning properly and replace it if necessary.
5. Clear the DTC using an OBD-II scanner and perform a test drive to verify the issue is resolved.

How to erase DTC B1865

To erase DTC B1865, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the ignition without starting the engine.
3. Access the trouble codes menu on the scanner.
4. Select the option to clear or erase the codes.
5. Confirm the action and wait for the scanner to indicate that the codes have been cleared.

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.