U2063 – Control Module Communication Bus Off.

The ODBII code U2063 indicates a communication issue where a control module is not able to communicate over the vehicle’s communication bus, often due to a fault in the module or wiring.

The severity of ODBII code U2063 is moderate to severe.

Common Causes For: U2062 Control Module Communication Bus Off.

• Faulty control module
• Damaged wiring or connectors
• Poor ground connections
• Communication bus short circuit
• Open circuit in the communication bus
• Corroded connectors
• Intermittent electrical issues
• Software or firmware issues in the control module
• Faulty or incompatible aftermarket parts
• Low battery voltage or power supply issues

Common misdiagnosis for U2063 Control Module Communication Bus Off.

• Faulty control module
• Wiring issues
• Poor ground connections
• Corrupted software/firmware
• Faulty connectors
• Battery or power supply issues
• Other communication bus faults (e.g., CAN bus issues)
• Sensor malfunctions
• Intermittent electrical connections
• Incorrectly diagnosed related codes

Common Troubleshooting Steps

The OBD-II code U2063 indicates a communication issue on the control module communication bus, specifically that a control module is “off” or not responding. This can be caused by various factors, including wiring issues, faulty modules, or problems with the communication bus itself. Here are some common troubleshooting steps to diagnose and resolve the U2063 code:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. This can provide more context about the issue.
• Inspect Wiring and Connectors: Visually inspect the wiring and connectors related to the control modules on the communication bus. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the ground connections, as poor grounding can lead to communication issues.
• Check the Control Modules: Identify the control module(s) that are part of the communication bus. This may include modules like the Engine Control Module (ECM), Transmission Control Module (TCM), Body Control Module (BCM), etc.
• If possible, test the affected control module(s) for proper operation. This may involve using a scan tool to check for communication with the module.
• Test the Communication Bus: Use a multimeter or an oscilloscope to check the voltage levels and signal integrity on the communication bus (e.g., CAN bus).
• Look for short circuits, open circuits, or abnormal voltage levels that could indicate a problem.
• Check for Intermittent Issues: Sometimes, communication issues can be intermittent. Wiggle the wiring harnesses and connectors while monitoring the communication to see if the issue can be replicated.
• Inspect for Software Issues: Ensure that the vehicle’s software is up to date. Sometimes, a software update can resolve communication issues.
• If a recent update was performed, consider whether it could have introduced the problem.
• Perform a Hard Reset: Disconnect the vehicle’s battery for a few minutes to reset the control modules. Reconnect the battery and see if the code reappears.
• Check for Environmental Factors: Ensure that there are no environmental factors affecting the communication, such as moisture or extreme temperatures.
• Consult Technical Service Bulletins (TSBs): Check for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on known issues related to communication bus problems.
• Replace Faulty Components: If a specific control module is identified as faulty, replace it. If wiring issues are found, repair or replace the damaged wiring or connectors.1
• Seek Professional Help: If the issue persists after performing these steps, consider seeking help from a professional mechanic or dealership with experience in diagnosing communication issues. By following these troubleshooting steps, you can systematically identify and resolve the underlying cause of the U2063 code.