U2215 – CAN Bus Communication Failure

The ODBII code U2215 indicates a “CAN Bus Communication Failure,” meaning there is a problem with the communication between the vehicle’s control modules over the Controller Area Network (CAN) bus.

The severity of ODBII code U2215 is moderate to high.

Common Causes For: U2214 U2214: Vehicle Communication Bus Malfunction

• Faulty CAN bus wiring or connectors
• Short circuit in the CAN bus
• Open circuit in the CAN bus
• Malfunctioning ECU (Electronic Control Unit)
• Corrupted software or firmware in the ECU
• Interference from aftermarket devices
• Poor ground connections
• Faulty termination resistors
• Damaged or worn-out CAN bus components
• Low battery voltage or power supply issues

Common misdiagnosis for U2215 U2215: “CAN Bus Communication Failure”

• Faulty CAN Bus wiring
• Defective ECU (Electronic Control Unit)
• Bad ground connections
• Malfunctioning sensors
• Corrupted software or firmware
• Faulty connectors or terminals
• Interference from aftermarket devices
• Low battery voltage or power supply issues
• Incorrectly configured or incompatible modules
• Physical damage to the CAN Bus network

Common Troubleshooting Steps

When dealing with OBD-II code U2215, which indicates a “CAN Bus Communication Failure,” there are several common troubleshooting steps you can follow to diagnose and potentially resolve the issue. Here’s a structured approach:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Other codes can provide context and help identify the root cause of the communication failure.
• Inspect the CAN Bus Wiring: **Visual Inspection: Check the wiring and connectors associated with the CAN bus for any visible damage, corrosion, or loose connections.
• **Wiring Continuity: Use a multimeter to check for continuity in the CAN bus wires. Look for breaks or shorts in the wiring.
• Check the Termination Resistors: The CAN bus requires termination resistors at both ends of the bus. Ensure that these resistors are present and functioning correctly (typically 120 ohms).
• Inspect the Modules: **Module Functionality: Check if the modules on the CAN bus (e.g., engine control module, transmission control module, etc.) are functioning properly. A malfunctioning module can disrupt communication.
• **Power and Ground: Ensure that all modules have proper power and ground connections.
• Test the CAN Bus Signal: Use an oscilloscope or a CAN bus analyzer to check the signal on the CAN bus. Look for proper voltage levels and signal integrity. The typical voltage levels should be around 2.5V for idle and should toggle between 0V and 5V when active.
• Check for Interference: Look for any sources of electrical interference that could be affecting the CAN bus communication. This could include aftermarket accessories or modifications.
• Disconnect Modules: If you suspect a specific module is causing the issue, you can try disconnecting it and see if the code clears or if communication is restored. Reconnect modules one at a time to identify the problematic one.
• Inspect the Vehicle’s Battery and Charging System: Ensure that the battery is in good condition and that the charging system is functioning properly. Low voltage can cause communication issues.
• Update or Reprogram Modules: In some cases, updating or reprogramming the affected modules may resolve communication issues. Check with the manufacturer for any available updates.
• Consult Technical Service Bulletins (TSBs): Check for any TSBs related to the specific make and model of the vehicle. Manufacturers may have identified common issues and solutions for CAN bus communication failures.1
• Professional Diagnosis: If the issue persists after performing the above steps, consider seeking help from a professional mechanic or automotive technician who has experience with CAN bus systems.Conclusion Troubleshooting a U2215 code can be complex due to the nature of the CAN bus system. Following these steps methodically can help identify and resolve the underlying issue. Always ensure safety precautions are taken when working on vehicle electrical systems.