P20EE P204F P208B Audi 3.0 TDI – AdBlue Pump Pressure & SCR Catalytic Efficiency
Diagnostic guide for P20EE, P204F, and P208B on Audi 3.0 TDI V6. Reductant supply pressure loss, delivery pump failure, and start-lockout warnings.
Vehicle
AUDI
Codes
3 units
Analysis Type
Technical Expert
Status
Analyzed
Technical Analysis
The combination of P20EE, P204F, and P208B indicates that the AdBlue reductant delivery pump cannot maintain specified rail pressure (4.5–6.0 bar), triggering SCR catalyst efficiency failure and engine restart countdowns.
Expected Symptoms
System Impact
Potential Fault Sources
Workflow / Methodology
Verify supply voltage and sensor telemetry for P20EE, P204F, P208B on AUDI with multimeter at key ON.
Check DPF differential pressure with key ON: must read precisely 0 hPa (0.48–0.52 V).
Query calculated soot mass and oil ash volume in ECM live data blocks.
Execute service regeneration cycle under load following sensor replacement.
Live Data & Mätvärdestoleranser (Är/Bör-värden)
Fabriksgodkända referensvärden vid diagnos och live-avläsning
| Parameter / Signal | Testvillkor | Bör-värde (Normalt) | Avvikelse / Varning |
|---|---|---|---|
| AdBlue Matartryck | Pump aktiv under drift | 4.5 – 6.0 bar | < 4.0 bar (Tryckfall/Pumpfel) |
| NOx-sensor uppströms (G295) | Normal landsvägslast | 150 – 600 ppm | Fastfruset 0 ppm el >1200 ppm |
| NOx-sensor nedströms (G687) | Varm SCR-katalysator (>220°C) | < 50 ppm | > 120 ppm (Otillräcklig rening) |
Assessment & Action Proposal
Technical Recommendation
Install a new genuine AdBlue delivery pump module, reset SCR restart inhibitor counter in the ECU, and clear DTCs.
Need a deeper analysis? Use our advanced fault code analyzer to find likely connections and in-depth guidance.
Start Fault Code AnalyzerVanliga frågor om dessa felkoder
Vad är den primära orsaken till felkoderna?
The combination of P20EE, P204F, and P208B indicates that the AdBlue reductant delivery pump cannot maintain specified rail pressure (4.5–6.0 bar), triggering SCR catalyst efficiency failure and engine restart countdowns.
Kan man köra vidare med tänd motorlampa / varningslampa?
Körning med aktiva felkoder kan leda till strypt motoreffekt (nödläge / Limp Home), blockerad partikelfilterregenerering eller följdskador på mekaniska komponenter. Felsökning bör genomföras omgående.
Hur åtgärdas kombinationen på säkrast sätt?
Install a new genuine AdBlue delivery pump module, reset SCR restart inhibitor counter in the ECU, and clear DTCs.