U0101 Lost Communication With TCM
What does U0101 mean?
U0101 — Lost Communication With TCM. This is an OBD-II diagnostic trouble code a scanner retrieves when your vehicle's computer detects lost communication with tcm. The level of risk depends on how the vehicle is currently running and how long you've been driving with the light on.
Common causes of U0101
- Open or shorted CAN bus wiring to the TCM
- TCM power or ground failure
- Failed TCM network interface
- Bad connector pin or corrosion
- Blown fuse supplying the TCM
How to fix U0101
- Check the TCM fuse and power supply
- Verify TCM grounds
- Inspect the data bus wiring and connectors to the TCM
- Measure bus resistance and check module network health with a scanner
- Replace the TCM if power and bus wiring test good