U2902 – Control Module Communication Failure

The ODBII code U2902 indicates a “Control Module Communication Failure,” meaning there is a problem with communication between the vehicle’s control modules, which can affect various systems and functions.

The severity of ODBII code U2902 is moderate.

Common Causes For: U2901 Lost Communication with the Hybrid Powertrain Control Module (HPCM) A.

• 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• Software glitches or outdated firmware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 U2902 U2902: “Control Module Communication Failure”

• Faulty control module
• Wiring issues
• Poor ground connections
• Corrupted software/firmware
• Faulty sensors
• Battery or power supply problems
• Intermittent connection issues
• Communication network faults (e.g., CAN bus issues)

Common Troubleshooting Steps

The OBD-II code U2902 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 the issue:

• Check for Other Codes: Use an OBD-II scanner to check for any additional trouble codes. Sometimes, other codes can provide context or lead to the root cause of the communication failure.
• Inspect Wiring and Connectors:
• Visually inspect the wiring and connectors associated with the control modules. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the wiring harnesses that connect the affected modules.
• Check Power and Ground:
• Ensure that the control modules have proper power and ground connections. Use a multimeter to check voltage and ground continuity.
• Verify that the fuses related to the control modules are intact.
• Test Control Modules:
• If possible, test the affected control modules individually to ensure they are functioning correctly. This may involve using specialized diagnostic tools or software.
• If a specific module is identified as faulty, consider replacing it.
• Inspect the CAN Bus:
• The Controller Area Network (CAN) bus is responsible for communication between modules. Check for any issues with the CAN bus wiring, such as shorts or opens.
• Use an oscilloscope to monitor the CAN bus signals if you have access to one.
• 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 control modules.
• 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):
• Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on known issues that could be relevant.
• 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 and diagnostics. By following these steps, you can systematically identify and address the underlying cause of the U2902 code.