U0401 — OBD-II trouble code

A network / communication OBD-II trouble code. Below are the vehicles and failure patterns where owners report it, drawn from NHTSA complaints.

In ProblemsByVin's analysis of the NHTSA owner-complaint record, owners cite U0401 across 20 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 U0401 20 patterns

2021 GMC Acadia

steering — Steering Assist Disabled / Reduced Warning

2020 GMC Terrain

brakes — Brake Vacuum Pump Failure

2019 Chevrolet Blazer

powertrain — Thermostat and Coolant Temperature Sensor Faults

2018 Buick Enclave

brakes — Complete Brake Pedal Failure

2018 Honda CR-V

powertrain — Loss of power/limp mode/fuel system malfunction

2017 Acura MDX

powertrain — Unintended shift to Neutral at speed

2017 Chevrolet Malibu

powertrain — Sudden power loss / reduced engine power in motion

2017 Chevrolet Colorado

powertrain — Transmission slipping and power loss

2016 Acura MDX

electrical — Electrical System Shutdown & Engine Start Failure

2016 Ford Fusion

steering — Loss of power steering assist with warning lights

2015 Dodge Dart

electrical — Unintended engine shutdown while driving

2014 Chevrolet Silverado

suspension — Front differential noise

2014 Ford F-150

powertrain — Transmission loss of power and limp mode (speedometer dropout)

2014 Jeep Patriot

electrical — Electronic Throttle Control (ETC) Stalling and Limp Mode

2014 Jeep Compass

powertrain — Transmission failure / loss of drive

2013 Ford Flex

steering — Power steering loss or assist fault — electrical control module failure

2013 Lincoln MKX

brakes — Hard brake pedal—excessive pedal effort

2011 Chrysler 200

engine — Engine stalling at idle and low speed

2011 Chrysler 200

powertrain — Engine stalling while driving

2006 Ford Five Hundred

powertrain — Transmission surging and lunging when shifting into Drive or Reverse

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 →