U2119 – Lost Communication with the Transmission Control Module (TCM).

The ODBII code U2119 indicates that there is a communication failure between the vehicle’s Engine Control Module (ECM) and the Transmission Control Module (TCM), meaning the ECM is unable to receive data from the TCM.

The severity of ODBII code U2119 is typically considered moderate to severe.

Common Causes For: U2118 Lost Communication with the Transmission Control Module (TCM) – Bus Off.

• Faulty Transmission Control Module (TCM)
• Damaged wiring or connectors
• Poor electrical connections
• Failed or malfunctioning engine control module (ECM)
• Blown fuses
• Corroded terminals
• Software issues or updates needed
• Low battery voltage or weak battery
• Faulty transmission wiring harness
• Issues with the vehicle’s CAN bus system

Common misdiagnosis for U2119 Lost Communication with the Transmission Control Module (TCM).

• Faulty Transmission Control Module (TCM)
• Wiring issues or damaged connectors
• Faulty Engine Control Module (ECM)
• Low transmission fluid levels
• Faulty vehicle speed sensor
• Corrupted software or firmware in TCM or ECM
• Issues with the CAN bus communication system
• Faulty or damaged transmission solenoids
• Battery or charging system problems
• Grounding issues in the electrical system

Common Troubleshooting Steps

When dealing with the OBD-II code U2119, which indicates “Lost Communication with the Transmission Control Module (TCM),” there are several common troubleshooting steps you can follow to diagnose and potentially resolve the issue. Here’s a structured approach:

• Check for Other Codes: Use an OBD-II scanner to check for any additional trouble codes. Codes related to the TCM or transmission may provide more context for the issue.
• Inspect Wiring and Connectors: **Visual Inspection: Check the wiring harness and connectors leading to the TCM for any signs of damage, corrosion, or loose connections.
• **Connector Pins: Ensure that the pins in the connectors are not bent, corroded, or damaged.
• Check Power and Ground: **Power Supply: Verify that the TCM is receiving the correct voltage. Use a multimeter to check the power supply to the TCM.
• **Ground Connections: Ensure that the ground connections for the TCM are secure and free of corrosion.
• Inspect the TCM: **Physical Condition: Check the TCM for any signs of physical damage or water intrusion.
• **Reprogramming: If applicable, consider reprogramming or updating the TCM software, as a software glitch can sometimes cause communication issues.
• Scan Tool Communication: **Communication Check: Use a scan tool to check if you can communicate with the TCM. If you cannot, it may indicate a problem with the TCM itself or the communication lines.
• **Other Modules: Check if you can communicate with other modules in the vehicle. If other modules are also unresponsive, it may indicate a broader communication issue.
• Check for Bus Communication Issues: **CAN Bus Inspection: If your vehicle uses a CAN bus system, check for issues on the bus. Look for short circuits, open circuits, or other faults that could disrupt communication.
• **Termination Resistors: Ensure that the CAN bus termination resistors are present and functioning correctly.
• Test the TCM: If all other checks are satisfactory, consider testing the TCM itself. This may involve swapping it with a known good unit if available.
• Check for Environmental Factors: **Temperature: Extreme temperatures can affect electronic components. Ensure that the TCM is not exposed to conditions that could cause it to fail.
• Consult Technical Service Bulletins (TSBs): Check for any TSBs related to your vehicle make and model that may address known issues with the TCM or communication problems.
• Professional Diagnosis: If you are unable to resolve the issue after these steps, it may be best to consult a professional mechanic or technician who has experience with your specific vehicle make and model.Conclusion Troubleshooting a U2119 code involves a systematic approach to check for communication issues between the TCM and other vehicle systems. By following these steps, you can identify the root cause of the problem and take appropriate action to resolve it.