OBD-II code · Powertrain (generic, extended)
P2D1F Reductant System Flow – Restricted
The SCR module detects restricted flow in the reductant system. Pressure rises above expected for the commanded dosing rate.
Is it safe to drive with P2D1F?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyReductant filter clogged
- PossibleSupply line kinked
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
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–6 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Reductant Lines, Reductant Injector, Reductant Pump, Scr Module
Related codes
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.