U1384 – Module Communication Failure

The ODBII code U1384 indicates a “Module Communication Failure,” which means there is a problem with communication between the vehicle’s control modules, potentially due to a wiring issue, a faulty module, or a network problem.

The severity of ODBII code U1384 is moderate.

Common Causes For: U1383 U1383: “Module Communication Failure”

• Faulty wiring or connectors
• Failed or malfunctioning control module
• Poor ground connections
• Corroded or damaged pins in connectors
• Intermittent electrical issues
• Software or firmware issues in the module
• Low battery voltage or weak battery
• Communication network issues (e.g., CAN bus problems)

Common misdiagnosis for U1384 U1384: “Module Communication Failure”

• Faulty wiring or connectors
• Defective control module
• Software issues or updates needed
• Power supply problems
• Grounding issues
• Intermittent communication issues
• Other module failures (e.g., ABS, BCM)
• Sensor malfunctions
• Corrupted data or configuration errors
• Environmental interference (e.g., moisture, corrosion)

Common Troubleshooting Steps

The OBD-II code U1384 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(s). Look for signs of damage, corrosion, or loose connections.
• Pay special attention to ground connections, as poor grounding can lead to communication issues.
• Check 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 receiving power, trace the wiring back to the fuse box and check for blown fuses or damaged wiring.
• Test the Module:
• If possible, test the affected module to ensure it is functioning correctly. This may involve using specialized diagnostic tools or swapping the module with a known good one.
• Some modules may have self-diagnostic capabilities that can provide additional information.
• Inspect the CAN Bus:
• If the vehicle uses a Controller Area Network (CAN) bus for communication, check the integrity of the CAN bus wiring. Look for shorts, opens, or interference.
• Use an oscilloscope or a CAN bus diagnostic tool to monitor the bus signals for proper communication.
• 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 inspections, 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 should be able to identify and resolve the underlying cause of the U1384 code.