P205FReductant System Performance (Bank 2)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P205F is the Bank 2 version of the reductant system performance check, meant for engines in which the second cylinder bank has its own SCR branch with separate pressure supply or valve. It applies when that branch is electrically sound but fails to reach or regulate the pressure or quantity the controller asks for. No manufacturer publicly documents P205F; even a V-engine such as Ram's 3.0 L EcoDiesel V6 lists delivery problems as P204F in its bulletins. The Bank 1 logic gives orientation: GM's 6.6 L LML waits for 30 failed build-up attempts below 350 kPa before setting a Type A code. CARB requires every SCR system to detect delivery faults before emissions exceed the limits. Look for blocked lines, a sticking valve or crystallised DEF in the second branch.
- What you may notice
- MIL and DEF warning on
- Higher NOx from Bank 2, possible inducement
- Likely causes
- LikelyBlocked or frozen DEF line to the Bank 2 branch
- PossibleBank 2 injector sticking due to DEF crystals
- PossibleInsufficient pump or metering unit pressure for the second branch
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.