U1315 – Module Communication Failure

The ODBII code U1315 indicates a communication failure between modules in the vehicle’s network, suggesting that one or more control modules are not able to communicate properly with each other.

The severity of ODBII code U1315: Module Communication Failure is generally considered moderate to severe.

Common Causes For: 1. U1311: Module Communication Failure

• Faulty wiring or connectors
• Failed or malfunctioning control module
• Corrosion or damage in the communication lines
• Poor ground connections
• Interference from aftermarket devices
• Software issues or incompatibility between modules
• Low battery voltage or power supply issues
• Faulty or damaged sensors affecting communication

Common misdiagnosis for 1. U1315: 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)
• Incorrectly installed aftermarket accessories

Common Troubleshooting Steps

The OBD-II code U1315 indicates a “Module Communication Failure,” which typically means that there is a problem with communication between the vehicle’s various 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, U1315 can be accompanied by other codes that can provide additional 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 the ground connections, as poor grounding can lead to communication issues.
• Check Power Supply: Ensure that the affected modules are receiving the proper voltage. Use a multimeter to check the power supply to the modules in question.
• Test Communication Lines:
• Use a scan tool to check the communication lines (CAN bus, LIN bus, etc.) for continuity and proper voltage levels.
• If you have access to an oscilloscope, you can check the signal waveforms on the communication lines to ensure they are functioning correctly.
• Inspect Modules:
• If you suspect a specific module is causing the issue, consider removing and inspecting it for physical damage.
• If possible, swap the suspected module with a known good one to see if the problem persists.
• 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 modules.
• Clear Codes and Test Drive: After performing any repairs or inspections, clear the trouble codes and take the vehicle for a test drive to see if the U1315 code returns.
• Consult Technical Service Bulletins (TSBs): Check for any TSBs related to the U1315 code for your specific vehicle make and model. Manufacturers may have specific recommendations or known issues that can help in troubleshooting.
• Professional Diagnosis: If the issue persists after performing the above steps, it may be necessary to consult a professional technician or dealership for further diagnosis. They may have specialized tools and knowledge to address complex communication issues. By following these steps, you can systematically identify and resolve the underlying cause of the U1315 code.