U1344 – Control Module Communication Fault

The ODBII code U1344: Control Module Communication Fault indicates a problem with communication between the vehicle’s control modules, which may affect their ability to share data and function properly.

Moderate to severe.

Common Causes For: U1324: Control Module Communication Failure

• Faulty control module
• Poor or damaged wiring/connectors
• Corroded terminals
• Software issues or bugs
• Low battery voltage
• Intermittent electrical connections
• Faulty ground connections
• Communication network issues (e.g., CAN bus problems)

Common misdiagnosis for U1344: Control Module Communication Fault

• Faulty control module
• Wiring issues or damaged connectors
• Corrupted software or firmware in the control module
• Power supply problems to the control module
• Faulty sensors or actuators
• Grounding issues
• Intermittent communication faults due to environmental factors
• Incorrectly installed aftermarket accessories or modifications

Common Troubleshooting Steps

The OBD-II code **U1344: Control Module Communication Fault** indicates a communication issue between the vehicle’s control modules. This can be caused by various factors, including wiring issues, faulty modules, or problems with the vehicle’s network. Here are some common troubleshooting steps to diagnose and resolve this issue:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Sometimes, other codes can provide more context for the communication fault.
• Inspect Wiring and Connectors:
• Visually inspect the wiring and connectors associated with the control modules. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the wiring harnesses that connect the modules, as these can be prone to wear and tear.
• Check Power and Ground:
• Ensure that the control modules have proper power and ground connections. Use a multimeter to check for voltage at the module connectors.
• Verify that the ground connections are clean and secure.
• Test Control Modules:
• If you suspect a specific control module is faulty, you can test it by swapping it with a known good module (if available) or using a diagnostic tool to perform module-specific tests.
• Check for any signs of physical damage or overheating on the modules.
• Inspect the CAN Bus:
• The communication between control modules often occurs over a Controller Area Network (CAN) bus. Inspect the CAN bus wiring for damage or shorts.
• Use an oscilloscope or a CAN bus diagnostic tool to check for proper signal levels and communication on the bus.
• Check for Interference:
• Look for any aftermarket devices or modifications that may interfere with the vehicle’s communication network, such as alarms, remote starters, or audio systems.
• 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 returns.
• Consult Service Manual:
• Refer to the vehicle’s service manual for specific diagnostic procedures related to the U1344 code and the control modules involved.
• Professional Diagnosis:
• If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership with advanced diagnostic tools and expertise in your vehicle’s make and model. By following these steps, you should be able to identify and resolve the underlying issue causing the U1344 code.