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U0101

Data bus, transmission control module (TCM) - no communication

U0101 is described as “Data bus, transmission control module (TCM) - no communication” in the Generic OBD2 reference. Other reference families are shown below; select the scope relevant to your vehicle.

Manufacturer reference family

BMW: U0101

en

Lost Communication with TCM

Reference namespace
bmw
Source revision
legacy-oem-dtc-r2-20260924

Reference family assigned by the production catalog. An entry in this family is not proof of a fault or ECU support on every listed vehicle.

Related catalog brands: BMW.

10 profiles assigned this reference family
Manufacturer reference family

GM: U0101

en

Lost Communication With Transmission Control Module Invalid Data

Reference namespace
gm
Source revision
legacy-oem-dtc-r2-20260924

Reference family assigned by the production catalog. An entry in this family is not proof of a fault or ECU support on every listed vehicle.

Manufacturer reference family

Genesis / Hyundai / Kia: U0101

ru

Потеря связи с TCM (C-CAN); Шина связи CAN с TCU (превышение времени ожидания); Потеря связи с TCM (C-CAN)

Reference namespace
hyundai-kia
Source revision
legacy-oem-dtc-r2-20260924

Reference family assigned by the production catalog. An entry in this family is not proof of a fault or ECU support on every listed vehicle.

Related catalog brands: Kia, Genesis, Hyundai.

401 profiles assigned this reference family

377 more related profiles are listed in the vehicle directory.

Manufacturer reference family

Mercedes-Benz: U0101

en

Lost Communication with TCM

Reference namespace
mercedes-benz
Source revision
legacy-oem-dtc-r2-20260924

Reference family assigned by the production catalog. An entry in this family is not proof of a fault or ECU support on every listed vehicle.

Related catalog brands: Mercedes-Benz.

13 profiles assigned this reference family
Generic OBD2

Generic OBD2: U0101

en

Data bus, transmission control module (TCM) - no communication

Reference namespace
obd2
Source revision
legacy-2.2.20

Generic OBD2 definition; confirm the protocol and vehicle-specific service information.

Manufacturer reference family

Belgee / Geely / Proton: U0101

en

CAN Diagnosis - Lost Communication with TCU

Reference namespace
proton
Source revision
legacy-oem-dtc-r2-20260924

Reference family assigned by the production catalog. An entry in this family is not proof of a fault or ECU support on every listed vehicle.

Related catalog brands: Belgee, Geely, Proton.

5 profiles assigned this reference family
Manufacturer reference family

Dacia / Renault: U0101

ru

Нет связи CAN-BUS с модулем управления трансмиссией MTA (Easytronic) C-006; Нет связи CAN-BUS с модулем управления трансмиссией C-001

Reference namespace
renault
Source revision
legacy-oem-dtc-r2-20260924

Reference family assigned by the production catalog. An entry in this family is not proof of a fault or ECU support on every listed vehicle.

Related catalog brands: Dacia, Renault.

170 profiles assigned this reference family

146 more related profiles are listed in the vehicle directory.

What should I check before using this definition?

Keep the full code, module, status and freeze-frame data. Confirm the vehicle’s make, model, year and current manufacturer service information before choosing a repair. This entry does not identify a failed part by itself.

Organize a scan report or recording
Source and applicability

OBD Lens production library legacy-owner-2026-10-09-v81. This is a scoped technical reference, not a scan of your car. A catalog relationship does not certify that every ECU, year or engine returns the same signal or code definition.

Read the reference method

OBD Lens reference library · catalog legacy-owner-2026-10-09-v81. Sources and scope