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U0306 Software Incompatibility With Fuel Injector Control Module

Check engine lightUsually off
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Some diesels fire their injectors through a separate fuel injector control module that raises the voltage and opens each injector when the engine controller commands it; Ford's 6.0 L Power Stroke used such a FICM at about 48 V, and GM's 2005 Duramax table watches its injector driver by a CAN status bit that must toggle every 20 ms. U0306 means the controllers judge the module's software or calibration as not matching, for example after a used or remanufactured FICM was fitted. Ford's 2014 OBD-II code interpretation carries U0306 without its MIL marker; other makers may rate it differently, because injection timing and quantity decide emissions. U0105 stands for lost contact, U0406 for invalid data. Depending on the strategy the engine runs roughly, drops into reduced power or will not start.

Likely causes

Used, remanufactured or wrong-variant injector module fitted without programming
Engine controller reflashed or replaced while the injector module kept old software
Programming of the injector module interrupted, e.g. by low battery voltage

Symptoms

  • Hard start or no start, engine may crank without firing
  • Rough running, misfire or reduced power
  • Further injector or injector module codes stored

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–1,200
Time0.5–3 h

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

Parts involved

injector driver moduleecmcontrol module software

Related codes

U0105U0406U0301U0307

References: performanceparts.ford.com, gsi.ext.gm.com, en.wikipedia.org.