U1617 – refers to a communication issue between the engine control module (ECM) and the transmission control module (TCM).

The ODBII code U1617 indicates a communication issue between the engine control module (ECM) and the transmission control module (TCM), suggesting a failure in data exchange between these two components.

The severity of OBDII code U1617 is typically considered moderate to high.

Common Causes For: U1616 Lost Communication with Body Control Module (BCM)”.

• Faulty wiring or connectors between ECM and TCM
• Failed ECM
• Failed TCM
• Corroded or damaged connectors
• Poor ground connections
• Software issues or programming errors
• Intermittent electrical issues
• Faulty sensors affecting communication
• Battery or charging system problems
• Aftermarket modifications or installations affecting communication

Common misdiagnosis for U1617 refers to a communication issue between the engine control module (ECM) and the transmission control module (TCM).

• Faulty ECM
• Faulty TCM
• Wiring issues or shorts
• Corroded connectors
• Faulty sensors (e.g., speed sensors)
• Software issues or updates needed
• Battery or charging system problems
• Grounding issues
• Transmission fluid issues
• Other communication errors in the vehicle’s network

Common Troubleshooting Steps

When dealing with OBD-II code U1617, which indicates a communication issue between the Engine Control Module (ECM) and the Transmission Control Module (TCM), there are several common troubleshooting steps you can follow:

• Check for Additional Codes: Start by scanning the vehicle for any other diagnostic trouble codes (DTCs). Other codes may provide additional context or indicate related issues.
• Inspect Wiring and Connectors:
• Visually inspect the wiring harness and connectors between the ECM and TCM for any signs of damage, corrosion, or loose connections.
• Ensure that all connectors are securely plugged in and that there are no bent pins.
• Check Power and Ground:
• Verify that the ECM and TCM are receiving the proper power supply and ground. Use a multimeter to check voltage and ground continuity.
• Look for blown fuses that may affect the communication between the modules.
• Test Communication Lines:
• Use a scan tool to check for communication between the ECM and TCM. If the TCM is not responding, it may indicate a problem with the module itself or the communication lines.
• Check for short circuits or open circuits in the communication lines (CAN bus).
• Inspect for Interference:
• Look for any aftermarket devices or modifications that may interfere with the communication between the ECM and TCM.
• Ensure that there are no electromagnetic interference sources nearby.
• Update Software/Firmware:
• Check if there are any available software updates for the ECM or TCM. Sometimes, manufacturers release updates to fix communication issues.
• Perform a Hard Reset:
• Disconnect the battery for a few minutes to reset the ECM and TCM. Reconnect and see if the code reappears.
• Check for Module Failure:
• If all other steps do not resolve the issue, consider the possibility of a faulty ECM or TCM. Testing or replacing the module may be necessary.
• Consult Technical Service Bulletins (TSBs):
• Look for any TSBs related to the U1617 code for your specific vehicle make and model. Manufacturers may have documented known issues and solutions.
• Professional Diagnosis:
• If you are unable to resolve the issue, it may be best to consult a professional mechanic or technician who has experience with your vehicle’s specific systems. By following these steps, you can systematically diagnose and potentially resolve the communication issue indicated by the U1617 code.