Powertrain
generic / SAE
P20FF
Reductant Control Module Performance
The dedicated SCR/reductant control module reports an internal performance fault — failed self-tests, watchdog resets, or calibration mismatch. Frequently a forerunner of total module failure.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number– / FF
Possible causes
- Internal module fault high
- Calibration mismatch after software update medium
- Module software outdated, reflash may resolve low
Symptoms
- Check engine light or NOx warning on
- AdBlue/DEF level or quality warning
- Possible no-start countdown after ignore period
- Failed emissions inspection (NOx)
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 600–3500 €
- Estimated time: 2–6 h
- Component: scr control module
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012