U1613 – Lost Communication with TCM (Transmission Control Module).

The ODBII code U1613 indicates that there is a communication failure between the vehicle’s control module and the Transmission Control Module (TCM), which may affect the transmission’s performance and functionality.

The severity of ODBII code U1613 is generally considered moderate to severe.

Common Causes For: U1612 U1612: “CAN Communication Malfunction Detected”

• Faulty Transmission Control Module (TCM)
• Wiring issues (damaged, corroded, or loose connections)
• Faulty connectors or terminals
• Software issues or programming errors
• Malfunctioning Engine Control Module (ECM)
• Low battery voltage or poor power supply
• Faulty sensors related to transmission operation
• Issues with the vehicle’s CAN bus communication system

Common misdiagnosis for U1613 Lost Communication with TCM (Transmission Control Module)”.

• Faulty Transmission Control Module (TCM)
• Wiring issues or damaged connectors
• Faulty Engine Control Module (ECM)
• Low transmission fluid levels
• Faulty sensors (e.g., speed sensors)
• Software issues or programming errors
• Battery or charging system problems
• Grounding issues
• Faulty transmission solenoids
• Corroded or loose electrical connections

Common Troubleshooting Steps

When dealing with the OBD-II code U1613, which indicates “Lost Communication with TCM (Transmission Control Module),” 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. Sometimes, other codes can provide context or indicate related issues.
• Inspect Wiring and Connectors: **Visual Inspection: Check the wiring harness and connectors related to the TCM for any signs of damage, corrosion, or loose connections.
• **Connector Pins: Ensure that the pins in the connectors are not bent or corroded.
• 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 Connection: Ensure that the ground connection for the TCM is secure and functioning properly.
• 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 see 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 Short Circuits: Inspect the wiring for any short circuits or open circuits that could be affecting communication between the TCM and the engine control module (ECM).
• Inspect the CAN Bus: If your vehicle uses a Controller Area Network (CAN) for communication, check the CAN bus wiring for faults. Look for any damaged wires or poor connections.
• Test the TCM: If all other checks are inconclusive, consider testing the TCM. This may involve swapping it with a known good unit or bench testing it if possible.
• Clear Codes and Test Drive: After performing repairs or checks, clear the codes and take the vehicle for a test drive to see if the code returns.
• Consult Technical Service Bulletins (TSBs): Check for any manufacturer-specific TSBs related to the U1613 code, as there may be known issues or fixes for your specific vehicle model.1
• Seek Professional Help: 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 vehicle’s make and model. By following these steps, you can systematically diagnose and address the U1613 code. Always ensure safety and proper procedures when working on vehicle electronics.