U0306Software Incompatibility With Fuel Injector Control Module
- Generic OBD-II code · Network
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- 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.
- What you may notice
- Hard start or no start, engine may crank without firing
- Rough running, misfire or reduced power
- Further injector or injector module codes stored
- Likely causes
- LikelyUsed, remanufactured or wrong-variant injector module fitted without programming
- PossibleEngine controller reflashed or replaced while the injector module kept old software
- RareProgramming of the injector module interrupted, e.g. by low battery voltage
- Inspection (ITP)
- Can matter for the ITP: it concerns the emissions system.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.