U030CSoftware Incompatibility With Reductant Quality Module
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- The reductant quality module tells the SCR system whether the tank holds proper urea solution (DEF/AdBlue); in many trucks it sits in the tank unit together with level and temperature sensing. U030C means the engine or dosing controller has rejected its software or calibration, as after a tank or sensor replacement with the wrong part number. Ford's 2014 code interpretation flags U030C as a MIL code; Ford's 2023 diesel summary calls the module RDQM and treats 5 s without its frames as lost communication (U02A2). CARB lets makers skip a direct reductant quality monitor only if an inducement strategy prevents long operation on poor fluid and its inputs, such as this sensor, are monitored themselves. Hence a MIL, DEF warnings and, if left unresolved, speed limits. U05A3 covers invalid data.
- What you may notice
- MIL and DEF/AdBlue system warning
- Countdown to speed limitation or no-restart shown
- Code appears after tank, heater or sensor replacement
- Likely causes
- LikelyDEF tank unit or quality sensor of a different part number installed
- PossibleEngine or dosing controller updated, quality module left on old software
- RareProgramming interrupted or wrong file loaded
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- 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.