Question 1

What does U0101 mean?

Accepted Answer

U0101 - Lost Communication with TCM. Vehicle lost communication with the Transmission Control Module.

Question 2

What are the symptoms of U0101?

Accepted Answer

Check engine light, Trans stuck in limp mode, Harsh or no shifts, Trans warning light

Question 3

What causes U0101?

Accepted Answer

TCM failure, CAN bus wiring issue, TCM fuse blown, TCM connector corrosion, Water damage, Trans wiring harness damage

Question 4

How much does it cost to fix U0101?

Accepted Answer

Typical repair cost: $100-$1,500. Check TCM fuses and power supply first. On some vehicles (Chrysler, VW), TCM is inside the transmission.

U0101 — Lost Communication with TCM

Don't guess — diagnose U0101 the right way