U1381 – Module Communication Failure

The ODBII code U1381 indicates a “Module Communication Failure,” which means there is a problem with communication between the vehicle’s control modules, often due to a wiring issue, a faulty module, or a network problem.

The severity of ODBII code U1381 is moderate.

Common Causes For: U1380 U1380: “Module Communication Failure”

• Faulty wiring or connectors
• Failed or malfunctioning module
• Poor ground connections
• Corroded or damaged pins
• Communication network issues (CAN bus problems)
• Software or firmware issues
• Intermittent electrical connections
• Low battery voltage or power supply issues

Common misdiagnosis for U1381 U1381: “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)
• Corrupted data or configuration errors

Common Troubleshooting Steps

The OBD-II code U1381 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 modules. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to ground connections, as poor grounding can lead to communication issues.
• Check Module Power Supply:
• Ensure that the affected module(s) are receiving the proper voltage and ground. Use a multimeter to check the power supply to the module.
• If the module is not receiving power, trace the wiring back to the fuse box and check for blown fuses or damaged wiring.
• 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.
• If the module is faulty, it may need to be repaired or replaced.
• Check for Network Issues:
• Inspect the CAN (Controller Area Network) bus wiring for shorts, opens, or other issues. The CAN bus is responsible for communication between modules.
• Use a scan tool to monitor the communication on the bus and check for any irregularities.
• Reset the Modules:
• Sometimes, simply resetting the modules can resolve communication issues. This can be done by disconnecting the battery for a few minutes or using a scan tool to clear the codes.
• Update Software/Firmware:
• Check if there are any software or firmware updates available for the affected modules. Sometimes, communication issues can be resolved with an update.
• 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 communication issues.
• Professional Diagnosis:
• If the issue persists after performing the above steps, it may be necessary to seek professional help. A qualified technician with experience in automotive electronics can perform more advanced diagnostics. By following these steps, you can systematically identify and address the root cause of the U1381 code.