U2168 – Module Communication Failure

The ODBII code U2168 indicates a communication failure between modules in the vehicle’s network, suggesting that one or more electronic control units (ECUs) are not able to communicate properly with each other.

The severity of ODBII code U2168 is moderate.

Common Causes For: U2167 U2167: “Module Communication Failure”

• Faulty wiring or connectors
• Malfunctioning control module
• Poor ground connections
• Corroded or damaged pins
• Communication network issues (CAN bus problems)
• Software or firmware issues
• Intermittent electrical connections
• Low battery voltage or power supply issues

Common misdiagnosis for U2168 U2168: “Module Communication Failure”

• Faulty wiring or connectors
• Defective control module
• Software issues or updates needed
• Battery or power supply problems
• Grounding issues
• Intermittent communication issues
• Other communication protocol failures

Common Troubleshooting Steps

The OBD-II code U2168 indicates a “Module Communication Failure,” which typically means that there is a problem with communication between the vehicle’s control modules. 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 other trouble codes that may be present. Sometimes, multiple codes can provide more context for the issue.
• Inspect Wiring and Connectors:
• Visually inspect the wiring and connectors associated with the affected module. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the ground connections, as poor grounding can lead to communication issues.
• Check Power Supply:
• Ensure that the affected module is receiving the proper voltage and ground. Use a multimeter to check the power supply to the module.
• If the module is not receiving power, trace the wiring back to the fuse box and check for blown fuses or damaged wiring.
• Test the Module:
• If possible, test the affected module to see if it is functioning correctly. This may involve using specialized diagnostic tools or swapping the module with a known good one.
• If the module is faulty, it may need to be repaired or replaced.
• Check for Communication:
• Use a scan tool to check if the affected module is communicating with other modules. If it is not, there may be a communication bus issue.
• Inspect the CAN (Controller Area Network) bus wiring for shorts, opens, or other issues.
• Look for Interference:
• Sometimes, aftermarket accessories or modifications can interfere with module communication. If any modifications have been made, consider removing them temporarily to see if the issue resolves.
• Perform a Network Test:
• Some advanced scan tools can perform a network test to check the integrity of the communication lines. This can help identify if there are any issues with the CAN bus.
• Reset the Modules:
• After addressing any identified issues, clear the trouble codes using the scan tool and see if the code returns. Sometimes, a reset can resolve temporary 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 common communication issues.
• Seek Professional Help:
• If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or dealership for further diagnosis. They may have access to more advanced diagnostic tools and resources. By following these steps, you can systematically diagnose and potentially resolve the U2168 code and the associated communication failure.