U2249 – Module Communication Failure

The ODBII code U2249 indicates a “Module Communication Failure,” meaning there is a problem with communication between the vehicle’s control modules, which may affect their ability to exchange data properly.

The severity of ODBII code U2249 is generally considered moderate.

Common Causes For: U2248 U2248: Vehicle Communication Bus Malfunction

• Faulty wiring or connectors
• Malfunctioning control module
• Poor ground connections
• Corroded or damaged pins
• Software issues or bugs
• Interference from aftermarket devices
• Low battery voltage
• Communication network issues (e.g., CAN bus problems)

Common misdiagnosis for U2249 U2249: “Module Communication Failure”

• Faulty wiring or connectors
• Defective control module
• Software issues or updates needed
• Battery or power supply problems
• Grounding issues
• Intermittent communication issues
• Other communication protocol failures

Common Troubleshooting Steps

The OBD-II code U2249 indicates a “Module Communication Failure,” which typically means that there is a problem with communication between the vehicle’s control modules. Here are some common troubleshooting steps to diagnose and resolve this issue:

• Check for Other Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Sometimes, multiple codes can provide more context for the issue.
• Inspect Wiring and Connectors:
• Visually inspect the wiring and connectors associated with the affected module. 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 module is receiving the proper voltage. Use a multimeter to check the power supply to the module.
• Verify that the fuses related to the module are intact and functioning.
• Test the Module:
• If possible, test the affected module by swapping it with a known good module (if applicable) to see if the problem persists.
• Some modules may have self-diagnostic capabilities; check for any internal fault codes.
• Inspect the CAN Bus:
• If the vehicle uses a Controller Area Network (CAN) bus, check the integrity of the CAN bus wiring. Look for shorts, opens, or high resistance in the bus lines.
• Use an oscilloscope to check the CAN bus signals if you have the necessary equipment and expertise.
• Check for Interference:
• Ensure that there are no aftermarket devices or modifications that could be interfering with the communication between modules.
• Update Software/Firmware:
• Check if there are any software or firmware updates available for the affected module. 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 reappears.
• Consult Technical Service Bulletins (TSBs):
• Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on known issues related to module communication.
• 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 the specific vehicle and its systems. By following these troubleshooting steps, you can systematically identify and resolve the underlying cause of the U2249 code.