U1567 – Communication Bus Off.

The ODBII code U1567 indicates a communication issue where the vehicle’s communication bus is offline or not functioning properly, affecting data exchange between modules.

The severity of ODBII code U1567 is moderate.

Common Causes For: U1565 Communication Bus Fault.

• Faulty wiring or connectors in the communication bus.
• Malfunctioning control modules.
• Short circuits or open circuits in the communication lines.
• Corrupted software or firmware in the control modules.
• Electrical interference from other components.
• Low battery voltage or poor power supply.
• Faulty or damaged sensors connected to the bus.

Common misdiagnosis for U1567 Communication Bus Off.

• Faulty ABS module
• Defective engine control module (ECM)
• Malfunctioning body control module (BCM)
• Wiring issues or shorts in the communication lines
• Faulty sensors or actuators
• Battery or charging system problems
• Incorrectly installed aftermarket accessories
• Software or firmware issues in modules

Common Troubleshooting Steps

The OBD-II code U1567 indicates a “Communication Bus Off” condition, which typically means that there is a communication issue between the vehicle’s control modules. This can be caused by a variety of factors, including wiring issues, module failures, or problems with the communication bus itself. Here are some common troubleshooting steps to diagnose and resolve the U1567 code:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. This can provide additional context for the issue.
• Inspect Wiring and Connectors: Visually inspect the wiring and connectors related to the communication bus (CAN bus). Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the connectors at the control modules involved in the communication.
• Test the Communication Bus: Use a multimeter or an oscilloscope to check the voltage levels on the CAN bus wires. The typical voltage levels should be around 2.5V to 2.7V when the bus is idle.
• Check for short circuits or open circuits in the communication lines.
• Check for Ground Issues: Ensure that all control modules have a good ground connection. Poor grounding can lead to communication issues.
• Inspect Control Modules: If the wiring and connections are good, the issue may lie with one of the control modules. Check for any signs of damage or failure.
• If possible, swap the suspected module with a known good one to see if the problem persists.
• Look for Interference: Check for any aftermarket devices or modifications that may interfere with the communication bus, such as alarms, remote starters, or audio systems.
• Perform a Network Test: Some advanced scan tools can perform a network test to check the integrity of the communication bus. This can help identify which module is causing the issue.
• Clear Codes and Test Drive: After performing the checks and repairs, clear the trouble codes and take the vehicle for a test drive to see if the code returns.
• Consult Service Manual: Refer to the vehicle’s service manual for specific diagnostic procedures related to the communication bus and the U1567 code.
• Seek Professional Help: If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who has experience with automotive electronics and communication systems. By following these troubleshooting steps, you should be able to identify and resolve the underlying issue causing the U1567 code.