U2520 – Control Module Communication Failure

The ODBII code U2520 indicates a “Control Module Communication Failure,” meaning there is a problem with communication between control modules in the vehicle, which may affect their ability to share data or function properly.

The severity of ODBII code U2520 is moderate.

Common Causes For: U2519 U2519: “Control Module Communication Failure”

• Faulty control module
• Damaged wiring or connectors
• Poor ground connections
• Corroded terminals
• Communication network issues (CAN bus problems)
• Software glitches or outdated firmware
• Interference from aftermarket devices
• Low battery voltage or power supply issues

Common misdiagnosis for U2520 U2520: “Control Module Communication Failure”

• Faulty control module
• Wiring issues
• Poor ground connections
• Corrupted software/firmware
• Faulty connectors or terminals
• Battery or power supply issues
• Intermittent communication faults
• Other communication protocol failures

Common Troubleshooting Steps

The OBD-II code U2520 indicates a “Control Module Communication Failure.” 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 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 Wiring and Connectors: **Visual Inspection: Check the wiring harnesses and connectors associated with the control modules for any signs of damage, corrosion, or loose connections.
• **Repair or Replace: Repair any damaged wires or connectors and ensure that all connections are secure.
• Check Power and Ground: **Power Supply: Verify that the control modules are receiving the correct voltage. Use a multimeter to check the power supply to the affected module.
• **Ground Connections: Ensure that the ground connections for the control modules are clean and secure.
• Test Control Modules: **Module Functionality: If possible, test the affected control module to ensure it is functioning correctly. This may involve using specialized diagnostic tools or software.
• **Swap Modules: If you have access to a similar vehicle, you can swap the control module to see if the problem persists.
• Check for Communication Issues: **CAN Bus Communication: If the vehicle uses a CAN (Controller Area Network) bus, check for communication issues on the bus. Use a scan tool to monitor the data on the bus and look for any anomalies.
• **Termination Resistors: Ensure that the CAN bus termination resistors are present and functioning correctly.
• Inspect for Interference: **Electrical Interference: Check for any aftermarket devices or modifications that may be causing electrical interference with the control modules.
• Update Software/Firmware: **Reprogramming: If the control module has outdated software, consider updating or reprogramming it using the manufacturer’s diagnostic tools.
• Clear Codes and Test Drive: After performing the above checks and repairs, 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): Check for any TSBs related to the specific make and model of the vehicle, as there may be known issues or fixes for the U2520 code.
• Seek Professional Help: If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with the specific vehicle and its control systems. By following these troubleshooting steps, you can systematically identify and resolve the underlying issue causing the U2520 code.