U0101 Code Explained: Lost Communication With TCM (How to FIX it!)

In this video, Jake breaks down fault code U0101 (Lost Communication With TCM) by explaining what it means, how the PCM/ECM, TCM, BCM, ABS and other modules communicate over the vehicle network (usually CAN), and why losing one module can trigger shifting issues and multiple warning lights. He covers the symptoms you’ll see and the broad categories of causes, then walks through a clean diagnostic plan: scan all modules to confirm which are offline and check related codes, verify battery/charging voltage, confirm TCM power and ground, inspect connectors and the harness, and test the CAN network for integrity (resistance with power off, signal/voltage checks with power on, and isolation steps to locate the fault). Finally, he shows how to apply the correct fix based on test results, clear the code, and verify communication stays stable on a re-scan and road test. Tools we recommend having for your vehicle at all times: OBD scanner: https://amzn.to/3OIM7Wl Air compressor: https://amzn.to/48gnZ3W Battery charger/jumper: https://amzn.to/4bN2jQe Electric ratchet wrench: https://amzn.to/3wfG2u1 Dewalt flashlights: https://amzn.to/42G6edd Flex-head ratchet wrenches: https://amzn.to/3SydrHM Grease monkey disposable gloves: https://amzn.to/3wghbX7 Magnetic pick up tools: https://amzn.to/3uwT0D4 Rollet seat: https://amzn.to/3up8QzN 8020 Automotive Website: https://8020automotive.com/ Check Out Our Portfolio: Tuning Pro - https://tuningpro.co/ BMW Tuning - https://bmwtuning.co/ Diesel IQ - https://dieseliq.com/ Chevy Trucks - https://chevytrucks.org/ Porsche Mania - https://porsche-mania.com/ Muscle Car Club - https://musclecarclub.com/ New Videos Every Week. Subscribe so you don't miss a video! ►Subscribe Here: https://bit.ly/3xtNUph --------------------------------------------------------------------- What is 8020 Automotive? 8020 Automotive owns and operates a portfolio of content websites and eCommerce stores in the Automotive industry. We provide over a million monthly readers with high-quality automotive content, focused predominantly on technical and performance modification guides. --------------------------------------------------------------------- 00:12 – What Does U0101 Stand For? 00:40 – How the Vehicle’s Internal System’s Communicate! 01:40 – Most Common Symptoms of a U0101 Fault Code! 02:12 – Most Common Causes of a U0101 Fault Code! 03:31 – How to Diagnose & Fix DTC U0101!