U2459 – Control Module Communication Bus Off.

The ODBII code U2459 indicates a communication issue where a control module is unable to communicate on the vehicle’s communication bus, often due to a fault in the module or wiring.

The severity of ODBII code U2459 is moderate to severe.

Common Causes For: U2458 Control Module Communication Bus Off.

• Faulty control module
• Poor electrical connections or wiring issues
• Shorted or open circuits in the communication bus
• Corroded connectors
• Faulty or damaged communication bus (CAN bus)
• Software or firmware issues in the control module
• Interference from aftermarket devices or modifications
• Low battery voltage or power supply issues

Common misdiagnosis for U2459 Control Module Communication Bus Off.

• Faulty control module
• Wiring issues
• Poor ground connections
• Corrupted software/firmware
• Battery or power supply problems
• Faulty connectors or terminals
• Other communication bus errors
• Sensor malfunctions

Common Troubleshooting Steps

The OBD-II code U2459 indicates a communication issue between control modules in a vehicle, specifically that a control module is “bus off.” This typically means that the module has detected a fault in the communication bus and has stopped transmitting messages to prevent further issues. Here are some common troubleshooting steps to diagnose and resolve the U2459 code:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Addressing related codes can help in diagnosing the issue.
• Inspect Wiring and Connectors: Visually inspect the wiring and connectors associated with the control modules. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the CAN (Controller Area Network) bus wiring, as this is often where communication issues arise.
• Check for Short Circuits or Open Circuits: Use a multimeter to check for continuity in the communication lines. Look for any short circuits or open circuits that could be affecting communication.
• Test the Control Modules: If possible, test the affected control module(s) to ensure they are functioning correctly. This may involve bench testing or swapping with a known good module.
• Inspect for Ground Issues: Ensure that all control modules have a good ground connection. Poor grounding can lead to communication issues.
• Check for Interference: Look for any aftermarket devices or modifications that may be interfering with the communication bus. This includes alarms, stereo systems, or other electronic devices.
• Update Software/Firmware: Check if there are any software or firmware updates available for the control modules. Sometimes, manufacturers release updates to fix communication issues.
• Clear Codes and Test Drive: After performing the above checks and repairs, clear the trouble codes using the OBD-II scanner 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 troubleshooting steps related to the U2459 code and the control modules involved.
• Professional Diagnosis: If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have specialized diagnostic tools and experience to resolve complex communication issues. By following these steps, you should be able to identify and resolve the underlying issue causing the U2459 code.