U2111 – Module Communication Failure

The ODBII code U2111 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 U2111 is generally considered moderate.

Common Causes For: U2110 Lost Communication with Vehicle Control Module.

• Faulty wiring or connectors
• Failed control module
• Corrupted software or firmware
• Poor ground connections
• Intermittent electrical issues
• Communication network issues (e.g., CAN bus problems)
• Low battery voltage or power supply issues
• Damaged or shorted circuits

Common misdiagnosis for U2111 U2111: “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 module failures
• Corrupted data or configuration errors

Common Troubleshooting Steps

The OBD-II code U2111 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, other codes can provide additional context for the U2111 code.
• Inspect Wiring and Connectors:
• Visually inspect the wiring and connectors associated with the affected modules. 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 modules are receiving the proper voltage. Use a multimeter to check the power supply to the modules.
• Test Communication Lines:
• Use a scan tool to check the communication lines (CAN bus, LIN bus, etc.) for continuity and proper voltage levels.
• If you have access to an oscilloscope, you can check the signal waveforms on the communication lines to ensure they are functioning correctly.
• Inspect Modules:
• If possible, check the affected module for any signs of damage or malfunction. This may involve removing the module and inspecting it physically.
• If you suspect a module is faulty, you may need to replace it or reprogram it.
• Check for Software Updates: Sometimes, communication issues can be resolved with a software update. Check with the manufacturer or a dealership to see if there are any updates available for the vehicle’s control modules.
• 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): Check for any TSBs related to the U2111 code for your specific vehicle make and model. Manufacturers may have issued guidance on common issues and fixes.
• Professional Diagnosis: If the issue persists after performing the above steps, it may be necessary to seek help from a professional mechanic or dealership with advanced diagnostic tools. By following these steps, you should be able to identify and resolve the underlying issue causing the U2111 code.