U2274 – Control Module Communication Bus Off.

The ODBII code U2274 indicates a communication issue where a control module is unable to communicate over the vehicle’s communication bus, often due to a fault in the module or wiring.

The severity of ODBII code U2274 is moderate to high.

Common Causes For: U2273 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
• Interference from aftermarket devices
• Software issues or bugs in the control module
• Low battery voltage or power supply issues

Common misdiagnosis for U2274 Control Module Communication Bus Off.

• Faulty control module
• Wiring issues
• Poor ground connections
• Corrupted software/firmware
• Faulty sensors
• Battery or power supply issues
• Communication network problems
• Intermittent connection issues

Common Troubleshooting Steps

The OBD-II code U2274 indicates a communication issue on the control module communication bus, specifically that a module is “off” or not responding. This can be caused by various issues, including wiring problems, module failures, or software issues. Here are some common troubleshooting steps to diagnose and resolve the U2274 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 Power Supply: Ensure that the affected control module is receiving the proper voltage. Use a multimeter to check the power supply to the module.
• Verify that the fuses related to the control modules are intact.
• Test the Control Module: If possible, perform a functional test of the control module that is reporting the U2274 code. This may involve using specialized diagnostic tools or software.
• If the module is not functioning correctly, it may need to be reprogrammed or replaced.
• Inspect the Communication Bus: Check the integrity of the communication bus (CAN bus, LIN bus, etc.) for shorts, opens, or other faults.
• Use an oscilloscope or a CAN bus analyzer to monitor the communication signals on the bus.
• Check for Software Updates: Verify if there are any software 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.
• Take the vehicle for a test drive to see if the code reappears. Monitor the performance of the affected systems.
• Consult Technical Service Bulletins (TSBs): Check for any TSBs related to the specific make and model of the vehicle. Manufacturers may have documented solutions for known issues.
• Seek Professional Help: If the issue persists after performing the above steps, consider seeking assistance from a qualified technician or automotive specialist who has experience with the specific vehicle and its systems. By following these troubleshooting steps, you can systematically identify and resolve the underlying issue causing the U2274 code.