U1400 – Invalid Data Received from Vehicle Control Module.

The ODBII code U1400 indicates that the vehicle’s control module has received invalid or corrupted data from another control module, suggesting a communication issue within the vehicle’s network.

The severity of ODBII code U1400 is generally considered moderate.

Common Causes For: U1399 is a manufacturer-specific code that generally indicates a communication issue within the vehicle’s network.

• Faulty Vehicle Control Module (VCM)
• Corrupted or damaged wiring harness
• Poor electrical connections
• Faulty communication lines (CAN bus issues)
• Malfunctioning sensors
• Software or firmware issues in the VCM
• Grounding issues
• Interference from aftermarket devices or modifications

Common misdiagnosis for U1400 Invalid Data Received from Vehicle Control Module.

• Faulty Vehicle Control Module (VCM)
• Wiring issues or short circuits
• Faulty Engine Control Module (ECM)
• Faulty Transmission Control Module (TCM)
• Sensor malfunctions (e.g., wheel speed sensors)
• Communication network issues (e.g., CAN bus problems)
• Battery or power supply issues
• Corrupted software or firmware in control modules

Common Troubleshooting Steps

The OBD-II code U1400 indicates that the vehicle’s control module has received invalid data from another control module. This can be caused by various issues, including communication problems between modules, wiring issues, or a malfunctioning control module. Here are some common troubleshooting steps to diagnose and resolve the U1400 code:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Addressing related codes can help pinpoint the issue.
• 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 involved in the communication.
• Check for Software Updates:
• Verify if there are any software updates available for the vehicle’s control modules. Sometimes, manufacturers release updates to fix communication issues.
• Test the Control Modules:
• If possible, test the control modules involved in the communication. This may require specialized diagnostic equipment or tools.
• If a specific module is suspected to be faulty, consider swapping it with a known good module (if available) to see if the issue persists.
• Inspect the CAN Bus:
• The U1400 code is often related to issues with the Controller Area Network (CAN) bus. Check for proper termination and continuity of the CAN bus wiring.
• Use a multimeter or oscilloscope to check for proper voltage levels and signal integrity on the CAN bus.
• Clear the Codes:
• After performing inspections 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.
• Check for Ground Issues:
• Ensure that all ground connections for the control modules are secure and free of corrosion. Poor grounding can lead to communication issues.
• Consult Technical Service Bulletins (TSBs):
• Check for any TSBs related to the U1400 code for your specific vehicle make and model. Manufacturers may have documented common issues and solutions.
• Professional Diagnosis:
• If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership with experience in diagnosing communication issues. By following these troubleshooting steps, you can systematically identify and resolve the underlying cause of the U1400 code.