U1311 – Module Communication Failure

The ODBII code U1311 indicates a communication failure between modules in the vehicle’s network, suggesting that one or more control modules are not able to communicate properly with each other.

The severity of ODBII code U1311: Module Communication Failure is generally considered moderate to severe.

Common Causes For: 1. U1111: Communication Fault Detected Between Modules

• Faulty wiring or connectors
• Failed control module
• Poor ground connections
• Intermittent communication issues
• Corrupted software or firmware
• Low battery voltage
• Electrical interference
• Damaged or corroded pins in connectors

Common misdiagnosis for 1. U1311: 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 (e.g., ABS, BCM)
• Incorrectly configured aftermarket accessories

Common Troubleshooting Steps

The OBD-II code U1311 indicates a “Module Communication Failure,” which typically means that there is a problem with communication between the vehicle’s control modules. This can be caused by various issues, including wiring problems, module failures, or issues with the vehicle’s network. Here are some common troubleshooting steps to diagnose and resolve the U1311 code:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Other codes can provide context and help identify the root cause of the communication failure.
• 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 Module Power Supply: Ensure that the affected modules are receiving the proper voltage and ground. Use a multimeter to check the power supply to the modules.
• If a module is not receiving power, trace the wiring back to the fuse box and check for blown fuses or damaged wires.
• Test Communication Lines: Use a scan tool to check the communication lines (CAN bus, LIN bus, etc.) for proper operation. You can use a multimeter or an oscilloscope to check for signal integrity.
• Look for short circuits, open circuits, or noise on the communication lines.
• Check for Module Malfunction: If the wiring and connections are good, the issue may be with the module itself. If possible, swap the suspected module with a known good one to see if the problem persists.
• If the module is faulty, it may need to be repaired or replaced.
• Perform a Network Test: Some advanced scan tools can perform a network test to check the communication between modules. This can help identify which module is not communicating properly.
• Reset the Codes: 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 Technical Service Bulletins (TSBs): Check for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on common communication issues.
• 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 issue causing the U1311 code.