P204F — AdBlue system: performance too low
Severity: Serious
Can you drive? With caution: limp mode possible, have it checked soon
Make: All makes (OBD-II standard)
| Meaning | AdBlue dosing is not achieving the expected result. The ECU compares how much it injects with what the NOx sensors read and finds too large a gap. |
| Family | Powertrain (P) |
Typical symptoms
AdBlue warning on the dashboard
Countdown before no-start
Reduced power
Countdown before no-start
Reduced power
Common causes
Weak AdBlue pump or blocked filter
Partially obstructed injector
Unreliable downstream NOx sensor
Non-compliant fluid
Partially obstructed injector
Unreliable downstream NOx sensor
Non-compliant fluid
What to do
Measure actual pump delivery and check the injector: these are repairable faults, whereas replacing sensors by trial and error is the most expensive route and often pointless.
Frequently asked questions
What does code P204F mean?
AdBlue system: performance too low. AdBlue dosing is not achieving the expected result. The ECU compares how much it injects with what the NOx sensors read and finds too large a gap.
Can I keep driving with code P204F active?
With caution: limp mode possible, have it checked soon
Common causes — P204F
Weak AdBlue pump or blocked filter Partially obstructed injector Unreliable downstream NOx sensor Non-compliant fluid
How do you fix code P204F?
Measure actual pump delivery and check the injector: these are repairable faults, whereas replacing sensors by trial and error is the most expensive route and often pointless.
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Where to get it fixed
Related codes
- P2000 — NOx Trap Efficiency Below Threshold Bank 1
- P2001 — NOx Trap Efficiency Below Threshold Bank 2
- P2002 — Diesel particulate filter (DPF) clogged
- P2003 — Particulate Trap Efficiency Below Threshold Bank 2
- P2004 — Intake Manifold Runner Control Stuck Open Bank 1
- P2005 — Intake Manifold Runner Control Stuck Open Bank 2
- P2006 — Intake Manifold Runner Control Stuck Closed Bank 1
- P2007 — Intake Manifold Runner Control Stuck Closed Bank 2
- P2008 — Intake Manifold Runner Control Circuit/Open Bank 1
- P2009 — Intake Manifold Runner Control Circuit Low Bank 1
- P200A — Component N15/3(ETC control module) is faulty.
- P200B — Component N15/3(ETC control module) is faulty.