U1337 – Control Module Communication Fault

The ODBII code U1337 indicates a communication fault between control modules in a vehicle, suggesting that one or more modules are not properly communicating with each other.

The severity of ODBII code U1337 is moderate.

Common Causes For: U1336 Manufacturer Specific” code, which typically indicates an issue related to the communication between modules in the vehicle’s network.

• Faulty control module
• Poor electrical connections
• Damaged wiring harness
• Corroded connectors
• Software issues or bugs
• Low battery voltage
• Faulty ground connections
• Interference from aftermarket devices
• Communication network issues (CAN bus problems)

Common misdiagnosis for U1337 U1337: “Control Module Communication Fault”

• Faulty control module
• Wiring issues
• Poor ground connections
• Corrupted software or firmware
• Faulty sensors
• Battery or charging system problems
• Intermittent connection issues
• Communication network faults (CAN bus issues)

Common Troubleshooting Steps

The OBD-II code U1337 indicates a “Control Module Communication Fault.” This code typically suggests that there is a problem with communication between various control modules in the vehicle. 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 additional trouble codes. Sometimes, other codes can provide context or lead to the root cause of 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 affected modules.
• Check Power and Ground: Ensure that the control modules have proper power and ground connections. Use a multimeter to check voltage and ground continuity.
• Verify that fuses related to the control modules are intact.
• Test Control Modules: If possible, test the affected control modules individually to ensure they are functioning correctly. This may involve using specialized diagnostic tools or software.
• If a specific module is identified as faulty, consider replacing it.
• Check for Intermittent Issues: Sometimes, communication faults can be intermittent. Monitor the vehicle for any patterns or specific conditions under which the fault occurs (e.g., temperature, driving conditions).
• Update Software/Firmware: Check if there are any software or firmware updates available for the control modules. Manufacturers may release updates to fix known communication issues.
• Clear Codes and Test Drive: After performing any repairs or checks, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code reappears.
• 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 issues related to control module communication.
• Professional Diagnosis: If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have access to advanced diagnostic tools and resources.
• Check for Environmental Factors: Sometimes, environmental factors such as moisture or extreme temperatures can affect module communication. Ensure that the vehicle is in a suitable environment for testing. By following these troubleshooting steps, you can systematically identify and resolve the underlying cause of the U1337 code.