Causes and Fixes U0101 Code: Lost Communication with TCM (Transmission Control Module)

How to fix a U0101 engine code: Lost Communication with TCM (Transmission Control Module)

Diagnosing a U0101 can be difficult and time-consuming.
DTC U010 is set when the transmission control module is unable to receive or send messages to the controller area network (CAN).
The CAN (Controller Area Network) is a protocol to allow the TCM and ECM modules, as well as other devices, to communicate with each other.

Symptoms
⦁ Multiple Warning Lights / No Gear Indicator
⦁ Vehicle will not shift
⦁ Vehicle stays in one gear (usually 2nd or 3rd) or in limp mode
⦁ Scan tool won’t communicate with the TCM

Possible Causes of the U0101 Code
⦁ Alternator Charging or Battery Issues
⦁ Blown Fuse
⦁ Wiring Open or Short
⦁ Problems with the TCM circuit
⦁ Problems with the data CAN bus
⦁ Faulty TCM

www.backyardmechanic.org
By using this information user assumes all risk of use.