U0101 — Lost communication with the transmission control module (TCM)

Code U0101 is a standard OBD-II diagnostic trouble code: Lost communication with the transmission control module (TCM).

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In our record, U0101 is reported most often on Chevrolet, Dodge and Mazda vehicles , against powertrain and electrical failure patterns , across 2005–2025 model years.

In ProblemsByVin's analysis of the NHTSA owner-complaint record, owners cite U0101 across 33 vehicle failure patterns. Diagnostic codes in complaints are reported by owners and are unverified — they point to where this code shows up, not a confirmed diagnosis. Open a page below for the full pattern (symptoms, mileage, repair costs owners cite).

Vehicles where owners report U0101 33 patterns

2025 GMC Sierra

engine — Crankshaft Thrust Bearing Wear / Excessive End Play

2023 Chevrolet Suburban

engine — Catastrophic engine failure / seizure

2022 GMC Sierra

powertrain — Transmission Valve Body Failure

2020 Chevrolet Silverado

brakes — Complete brake system failure / loss of braking power

2019 Chevrolet Equinox

powertrain — Transmission Failure / Shuddering / Hard Shifting

2018 Chevrolet Malibu

electrical — Check Engine Light / Engine Power Reduced

2016 Chevrolet Colorado

steering — Intermittent power steering loss with voltage drop

2015 Chevrolet Sonic

powertrain — Transmission Control Module (TCM) Failure

2015 Dodge Dart

powertrain — Transmission control module (TCM) bracket failure and module communication loss

2015 Jeep Patriot

powertrain — CVT transmission overheating and limp mode / loss of power

2014 Chevrolet Malibu

electrical — Auto Stop/Start System Failure

2014 Chevrolet Equinox

powertrain — Unexpected power loss and limp mode

2014 Chevrolet Impala

powertrain — Transmission Control Module Communication Loss

2014 Chevrolet Spark

powertrain — Stalling & Complete Loss of Power

2014 Dodge Charger

powertrain — Transmission slipping, rough shifting, loss of power during acceleration

2014 Ford Focus

electrical — Loss of power and stalling (limp mode / complete shutdown)

2013 Cadillac CTS

powertrain — Transmission Failure / Inability to Shift

2013 Chevrolet Sonic

powertrain — Transmission Control Module (TCM) Failure

2013 Dodge Dart

powertrain — Dual Dry Clutch Transmission (DDC) Failure

2013 Mazda Mazda3

powertrain — Transmission Control Module (TCM) malfunction and overheating

2012 Chevrolet Impala

electrical — Traction Control, ABS, and Stability Control System Activation

2012 Ford Focus

powertrain — Transmission Control Module (TCM) Failure

2012 GMC Acadia

powertrain — Multiple electrical and control module failures

2012 Mazda Mazda3

powertrain — Sudden power loss and transmission disengagement (automatic)

2010 Hyundai Elantra

powertrain — Transmission slipping and delayed/hesitant shifting

2010 Mazda Mazda3

electrical — Wiring Harness Faults & Battery Connection Issues

2008 Cadillac CTS

powertrain — Multiple System Failure / Loss of Engine Control

2008 Chevrolet Tahoe

electrical — Electrical system power loss and intermittent control failures

2008 Dodge Caliber

powertrain — CVT Transmission Failure

2006 Dodge Charger

powertrain — Random engine stalling and loss of power

2006 Mazda Mazda3

powertrain — Transmission computer communication and control module failure

2005 Chevrolet Cobalt

powertrain — Transmission shifting hard and jerking

2005 Chevrolet Cobalt

brakes — Brake pedal soft then hard / loss of braking pressure

Codes are pulled from what owners wrote in their NHTSA filings — they're allegations, not a shop diagnosis. Always confirm with a live scan. Browse all diagnostic codes →