OBD-II code · Powertrain (generic, extended)
P20EF Reductant Injection Valve Performance
The SCR reductant injection valve does not deliver the commanded amount of reagent. Causes include clogging by urea crystals, electrical faults or incorrect spray pattern.
Is it safe to drive with P20EF?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyUrea crystals in dosing valve
- PossibleElectrical fault in dosing valve
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)
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–4 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Def Dosing Valve, Def Pump
Related codes
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.