U2908 – Module Communication Failure

The ODBII code U2908 indicates a “Module Communication Failure,” meaning there is a problem with communication between vehicle control modules, which may affect their ability to share data or function properly.

The severity of ODBII code U2908 is moderate.

Common Causes For: U2907 U2907: “Vehicle Communication Bus Malfunction”

• Faulty wiring or connectors
• Failed or malfunctioning control module
• Poor ground connections
• Intermittent communication issues
• Software or firmware issues
• Corroded terminals
• Electrical interference
• Low battery voltage or power supply issues

Common misdiagnosis for U2908 U2908: “Module Communication Failure”

• Faulty wiring or connectors
• Defective control module
• Software issues or firmware corruption
• Power supply problems
• Grounding issues
• Intermittent communication issues
• Other communication protocol failures

Common Troubleshooting Steps

The OBD-II code U2908 indicates a “Module Communication Failure,” which typically means that there is a problem with communication between various modules in the vehicle’s network. 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(s). 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 Module Power Supply:
• Ensure that the affected module is receiving the proper voltage and ground. Use a multimeter to check the power supply to the module.
• If the module is not powered correctly, trace the wiring back to the power source.
• Test the Affected Module:
• If possible, test the affected module to see if it is functioning correctly. This may involve using specialized diagnostic tools or swapping the module with a known good one.
• Inspect the CAN Bus:
• If the vehicle uses a Controller Area Network (CAN) bus, check for issues with the bus itself. Look for short circuits, open circuits, or other faults in the wiring.
• Use a CAN bus diagnostic tool to monitor the communication on the bus and identify any anomalies.
• Check for Software Updates:
• Sometimes, communication issues can be resolved with a software update. Check with the vehicle manufacturer for any available updates for the affected module(s).
• Clear Codes and Test Drive:
• After performing any repairs or adjustments, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns.
• 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 common communication issues.
• Professional Diagnosis:
• If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership with experience in diagnosing module communication issues. By following these steps, you can systematically identify and resolve the underlying cause of the U2908 code.