U2604 – Invalid Data Received from Vehicle Communication Bus.

The ODBII code U2604 indicates that the vehicle’s communication bus has received invalid data, suggesting a potential issue with data transmission between modules.

The severity of ODBII code U2604 is moderate.

Common Causes For: U2602 CAN Communication Bus Off.

• Faulty OBD-II connector
• Damaged wiring or connectors in the communication bus
• Malfunctioning control modules
• Poor ground connections
• Interference from aftermarket devices
• Software issues or bugs in the control modules
• Corrupted data transmission
• Low battery voltage or power supply issues

Common misdiagnosis for U2604 Invalid Data Received from Vehicle Communication Bus.

• Faulty ECM (Engine Control Module)
• Faulty BCM (Body Control Module)
• Wiring issues or shorts in the communication bus
• Faulty sensors or actuators
• Corrupted software or firmware in modules
• Poor ground connections
• Battery or power supply issues
• Incorrectly installed aftermarket accessories or devices

Common Troubleshooting Steps

The OBD-II code U2604 indicates that there is an issue with the communication between the vehicle’s control modules, specifically that invalid data has been received from the vehicle communication bus. 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, multiple codes can provide more context about the issue.
• Inspect Wiring and Connectors:
• Examine the wiring and connectors associated with the communication bus (CAN bus) for any signs of damage, corrosion, or loose connections.
• Pay special attention to the connectors on the modules that are communicating over the bus.
• Check for Short Circuits or Open Circuits:
• Use a multimeter to check for continuity in the communication lines. Look for any short circuits or open circuits that could be causing communication issues.
• Inspect Modules:
• Check the control modules (ECU, TCM, BCM, etc.) for any signs of damage or malfunction. If a specific module is suspected, it may need to be tested or replaced.
• Verify Power and Ground:
• Ensure that all relevant modules have proper power and ground connections. A lack of power or a poor ground can lead to communication issues.
• Check for Interference:
• Look for any aftermarket devices or modifications that may be interfering with the communication bus. This includes things like alarm systems, stereo systems, or other electronic devices.
• Perform a Network Test:
• Some advanced scan tools can perform a network test to check the integrity of the communication bus. This can help identify if a specific module is not responding correctly.
• Clear Codes and Test Drive:
• After performing any repairs or adjustments, clear the trouble codes and take the vehicle for a test drive to see if the code returns.
• Update Software/Firmware:
• In some cases, updating the software or firmware of the control modules may resolve communication issues.
• Consult Technical Service Bulletins (TSBs):
• Check for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on known issues related to communication codes. 1
• Seek Professional Help:
• If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who specializes in automotive electronics. By following these steps, you can systematically diagnose and potentially resolve the U2604 code.