U2199 – Module Communication Line Fault

The ODBII code U2199 indicates a “Module Communication Line Fault,” which means there is a communication issue between the vehicle’s control modules, potentially due to a wiring problem, a faulty module, or interference in the communication network.

The severity of ODBII code U2199 is generally considered moderate.

Common Causes For: U2198 Lost Communication with the Hybrid Powertrain Control Module (HPCM)”.

• Faulty wiring or connectors
• Malfunctioning control modules
• Poor ground connections
• Corroded or damaged pins in connectors
• Intermittent electrical connections
• Software issues or bugs in the control modules
• Low battery voltage or power supply issues
• Faulty communication bus (CAN bus) components
• Aftermarket modifications or installations affecting communication
• Environmental factors (moisture, temperature extremes) affecting connections

Common misdiagnosis for U2199 U2199: “Module Communication Line Fault”

• Faulty OBDII connector
• Bad ground connections
• Defective control modules
• Wiring harness issues
• Corroded connectors
• Software glitches in modules
• Battery or power supply problems
• Intermittent communication issues
• Faulty sensors
• Incorrectly configured aftermarket devices

Common Troubleshooting Steps

The OBD-II code U2199 indicates a “Module Communication Line Fault,” which typically means that there is a problem with the communication between various control modules in the vehicle. 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, other codes can provide context or indicate which module is having communication issues.
• Inspect Wiring and Connectors:
• Visually inspect the wiring and connectors associated with the affected modules. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the communication lines (CAN bus lines) between modules.
• Check Power and Ground:
• Ensure that the affected modules are receiving proper power and ground. Use a multimeter to check voltage and ground continuity.
• If a module is not receiving power, trace the wiring back to the fuse box or battery.
• Test Communication Lines:
• Use a scan tool to monitor the communication between modules. Check if the affected module is responding to requests from the scan tool.
• If possible, use an oscilloscope to check the signal on the CAN bus lines for proper voltage levels and signal integrity.
• Inspect Modules:
• If a specific module is identified as the source of the problem, inspect it for physical damage or signs of water intrusion.
• If the module is removable, consider swapping it with a known good module to see if the problem persists.
• Check for Software Updates:
• Sometimes, communication issues can be resolved with a software update. Check with the manufacturer for any available updates for the affected modules.
• Clear Codes and Test Drive:
• After performing any repairs or inspections, clear the trouble codes and take the vehicle for a test drive to see if the code returns.
• Consult Wiring Diagrams:
• Refer to the vehicle’s service manual for wiring diagrams to understand the communication network and identify any potential issues.
• Professional Diagnosis:
• If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership with advanced diagnostic tools. By following these steps, you should be able to identify and resolve the underlying issue causing the U2199 code.