Network, generic

U0401 Invalid Data Received From ECM/PCM A

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

U0401 is stored by a module that keeps receiving the engine or powertrain controller's messages but finds their content faulty. Most often the transmission controller logs it; Ford's 2012 OBD summary names engine torque and pedal position as the data concerned. In GM's 2025 tables the TCM checks rolling counter, protection value and checksum of several ECM frames, treats 8 bad results within 18 checks as a failure and classes the code Type A (MIL at once); GM's driver-assist module sets it as Type C and only switches off adaptive cruise. Saab's 2011 code list adds sub-codes 72 (counter) and 74 (checksum). Bentley's Continental GT gearbox stores U040100 when brake pressure decays too fast in ACC stops; a passive entry can stay. Ford's 2020 Escape and GM's 2024 Corvette needed new software. U0100 means lost contact.

Likely causes

Software of the ECM/PCM or of the receiving module (update available)
ECM sends a signal flagged invalid, for example after its own sensor fault
Disturbed CAN traffic from connectors, wiring or low battery voltage
Engine control module internally faulty

Symptoms

  • Check engine light, often stored in the transmission controller
  • Harsh shifts or transmission limp-home mode
  • Adaptive cruise control switched off

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–1,500
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

ecmcan bus wiring

Related codes

U0100U0301U0402U0400

References: gsi.ext.gm.com, newtonnet.co.uk, saabwisonline.com, static.nhtsa.gov.