U1619 – refers to a communication issue between the engine control module (ECM) and the transmission control module (TCM).

The ODBII code U1619 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 ODBII code U1619 is generally considered moderate to high.

Common Causes For: U1618 refers to a communication issue between the engine control module (ECM) and the transmission control module (TCM).

• Faulty wiring or connectors between ECM and TCM
• Failed ECM or TCM
• Corrupted software or firmware in ECM or TCM
• Poor ground connections
• Short circuits or open circuits in the communication lines
• Interference from other electronic components
• Low battery voltage or weak battery
• Faulty CAN bus communication system

Common misdiagnosis for U1619 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 U1619, 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 to diagnose and potentially resolve the issue:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Sometimes, other codes can 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 for Short Circuits or Open Circuits:
• Use a multimeter to test for continuity in the wiring between the ECM and TCM. Look for any short circuits or open circuits that could be causing communication issues.
• Inspect Ground Connections:
• Ensure that the ground connections for both the ECM and TCM are clean and secure. Poor ground connections can lead to communication problems.
• Check Power Supply:
• Verify that both the ECM and TCM are receiving the correct voltage. Use a multimeter to check the power supply to both modules.
• Look for Software Updates:
• Check if there are any software updates available for the ECM or TCM. Sometimes, manufacturers release updates to address communication issues.
• Perform a Hard Reset:
• Disconnect the battery for a few minutes to reset the ECM and TCM. Reconnect the battery and see if the code reappears.
• Inspect for Interference:
• Check for any aftermarket accessories or modifications that may be interfering with the communication between the ECM and TCM.
• Test Modules:
• If possible, test the ECM and TCM individually to ensure they are functioning correctly. This may involve using specialized diagnostic equipment.
• Consult Technical Service Bulletins (TSBs):
• Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have documented known issues and solutions. 1
• Seek Professional Help:
• If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who has experience with the specific vehicle and its systems. By following these troubleshooting steps, you can systematically identify and address the communication issue indicated by the U1619 code.