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U033F Software Incompatibility With Hybrid/EV Battery Interface Control Module F

Check engine lightUsually off
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Public documents name no vehicle that uses U033F, nor a pack with exactly six interface boards; F is simply the sixth address in the row. What is documented is how strictly battery software must follow the hardware. Hyundai's bulletin 18-HC-003 requires a BMS parameter update whenever a replacement lithium battery is installed in a 2011–2015 Sonata Hybrid or a 2015–2017 Tucson Fuel Cell. FCA cured P1A29, a failure of cell supervisory circuit A on the 2026 RAM 1500 eTorque, with new battery pack control module software (08-282-26); owners had noticed limp-home mode and a disabled stop/start. CARB 1968.2 counts cell voltage sensing among the hybrid inputs OBD must watch. U01A5 and U04A6 are F's partners.

Likely causes

Battery parameters not updated after a pack or module replacement
Board F taken from another pack with a different software level
Battery controller on an outdated calibration

Symptoms

  • Limp-home mode or reduced electric power
  • Stop/start or electric assist disabled
  • Battery or hybrid warning after battery service

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€60–700
Time0.3–2 h

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

Parts involved

hv battery interface module f

Related codes

U01A5U04A6U033EU0340

References: static.nhtsa.gov, static.nhtsa.gov, law.cornell.edu.