U2219 – CAN Bus Communication Failure

The ODBII code U2219 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 U2219 is moderate to severe.

Common Causes For: U2218 Lost Communication with the Instrument Cluster.

• Faulty CAN bus wiring or connectors
• Short circuit in the CAN bus
• Open circuit in the CAN bus
• Malfunctioning control modules
• Poor ground connections
• Interference from other electronic devices
• Corroded or damaged connectors
• Software issues or bugs in the control modules
• Low battery voltage or power supply issues
• Faulty termination resistors

Common misdiagnosis for U2219 U2219: “CAN Bus Communication Failure”

• Faulty CAN Bus wiring
• Defective ECU (Engine Control Unit)
• Malfunctioning sensors
• Bad ground connections
• Faulty or damaged connectors
• Issues with other control modules
• Software glitches or outdated firmware
• Battery or power supply problems
• Interference from aftermarket devices
• Corrupted data or communication errors

Common Troubleshooting Steps

When dealing with OBD-II code U2219, 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. Sometimes, multiple codes can provide more context for the issue.
• 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 CAN Bus Termination Resistors: Ensure that the termination resistors (typically 120 ohms) are present and functioning at both ends of the CAN bus. A missing or faulty resistor can cause communication issues.
• Inspect Modules on the CAN Bus: Identify all modules connected to the CAN bus (e.g., engine control module, transmission control module, ABS module, etc.) and check for any signs of failure or malfunction.
• Disconnect and reconnect the modules to ensure good connections.
• Test the CAN Bus Signal: Use an oscilloscope or a CAN bus analyzer to check the signal on the CAN bus. You should see a square wave signal if the bus is functioning correctly.
• Look for noise or irregularities in the signal that could indicate a problem.
• Check for Ground Issues: Ensure that all ground connections related to the CAN bus and the modules are secure and free of corrosion. Poor grounding can lead to communication failures.
• Inspect for Interference: Check for any devices or components that may be causing electrical interference with the CAN bus communication.
• Perform a Hard Reset: Disconnect the vehicle’s battery for a few minutes to reset the vehicle’s computer systems. Reconnect and see if the code reappears.
• Update or Reprogram Modules: In some cases, a software update or reprogramming of the affected modules may be necessary. Check with the manufacturer for any available updates.
• Consult Technical Service Bulletins (TSBs): Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have known issues and solutions for CAN bus communication failures.1
• Seek Professional Help: If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who specializes in automotive electronics.Conclusion Troubleshooting a U2219 code can be complex due to the nature of the CAN bus system. Following these steps methodically can help identify the root cause of the communication failure. Always refer to the vehicle’s service manual for specific procedures and specifications related to the CAN bus system.