U2208 – Module Communication Line Fault

The ODBII code U2208 indicates a communication fault between modules in the vehicle, suggesting that one or more control modules are unable to communicate properly with each other.

The severity of ODBII code U2208 is moderate.

Common Causes For: U2207 U2207: “Control Module Communication Fault”

• Faulty wiring or connectors
• Short circuits in the communication line
• Open circuits in the communication line
• Malfunctioning control modules
• Corroded or damaged connectors
• Poor ground connections
• Interference from aftermarket devices
• Software issues or bugs in the modules
• Low battery voltage or power supply issues
• Faulty CAN bus transceiver

Common misdiagnosis for U2208 U2208: “Module Communication Line Fault”

• Faulty wiring or connectors
• Defective control module
• Low battery voltage
• Corrupted software or firmware
• Intermittent communication issues
• Grounding problems
• Other communication line faults (e.g., CAN bus issues)
• Faulty sensors or actuators

Common Troubleshooting Steps

The OBD-II code U2208 indicates a “Module Communication Line Fault,” which typically means there is a problem with the communication between various modules in the vehicle’s network. 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. Other codes can provide context and help identify the root cause of the communication issue.
• Inspect Wiring and Connectors: Visually inspect the wiring and connectors associated with the affected modules. Look for signs of damage, corrosion, loose connections, or frayed wires.
• Pay special attention to the communication lines (CAN bus, LIN bus, etc.) that connect the modules.
• Test the Modules: Identify which module is reporting the U2208 code. This could be a specific control module (e.g., ABS, BCM, ECM).
• If possible, test the affected module for proper operation. This may involve using a scan tool to check for communication with other modules.
• Check Power and Ground: Ensure that the affected module has proper power and ground connections. Use a multimeter to verify voltage and ground continuity.
• Check the fuses related to the affected module and replace any that are blown.
• Inspect the CAN Bus: If the vehicle uses a CAN bus system, check the integrity of the bus. Look for short circuits, open circuits, or resistance issues.
• Use an oscilloscope or a CAN bus tester to monitor the communication signals on the bus.
• Perform a Network Test: Some advanced scan tools can perform a network test to check for communication issues between modules. Use this feature if available.
• Reset the Modules: Clear the trouble codes using the OBD-II scanner and see if the code returns. Sometimes, a temporary glitch can cause communication faults.
• Update Software/Firmware: Check if there are any software or firmware updates available for the affected modules. Sometimes, communication issues can be resolved with an update.
• Replace Faulty Components: If a specific module is determined to be faulty after testing, consider replacing it. Ensure that the replacement module is compatible with your vehicle.
• Consult Technical Service Bulletins (TSBs): Look for any TSBs related to the U2208 code for your specific vehicle make and model. Manufacturers may have known fixes or recommendations for this issue.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 troubleshooting steps, you can systematically identify and resolve the underlying cause of the U2208 code.