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AUDI
P229F
P20EE
P2200

P229F P20EE P2200 Audi 3.0 TDI – NOx Sensor Bank 1 Sensor 2 Circuit & SCR Efficiency

Diagnostic Priority: High
Complexity Level: Advanced

Diagnostic guide for P229F, P20EE, and P2200 on Audi 3.0 TDI V6. Downstream NOx sensor G687 circuit fault, upstream G295, and SCR catalyst efficiency loss.

Vehicle

AUDI

Codes

3 units

Analysis Type

Technical Expert

Status

Analyzed

Technical Analysis

REF: #9F6301

The combination of P229F, P20EE, and P2200 indicates NOx sensor element degradation (upstream G295 or downstream G687) on Audi 3.0 TDI V6 engines, resulting in SCR system efficiency fault codes.

Expected Symptoms

Glow plug light flashing and DPF icon illuminated on instrument cluster on AUDI (DTCs: P229F, P20EE, P2200)
Engine enters limp home mode restricting engine output above 2,200 RPM
Acrid exhaust odor and elevated fuel consumption due to aborted DPF regenerations

System Impact

Drivetrain
Engine Control
Emission Control

Potential Fault Sources

01Defective differential pressure sensor G450 or split silicone sample lines (affecting AUDI subsystem for P229F, P20EE, P2200)
02Severe soot loading in DPF caused by short-trip driving and fouled injectors
03Sticking EGR cooler changeover flap or faulty exhaust gas temp sensor G235 (logged fault: P229F)

Workflow / Methodology

01

Verify supply voltage and sensor telemetry for P229F, P20EE, P2200 on AUDI with multimeter at key ON.

02

Check DPF differential pressure with key ON: must read precisely 0 hPa (0.48–0.52 V).

03

Query calculated soot mass and oil ash volume in ECM live data blocks.

04

Execute service regeneration cycle under load following sensor replacement.

Live Data & Mätvärdestoleranser (Är/Bör-värden)

Fabriksgodkända referensvärden vid diagnos och live-avläsning

Mätvärdesblock
Parameter / SignalTestvillkorBör-värde (Normalt)Avvikelse / Varning
AdBlue MatartryckPump aktiv under drift4.5 – 6.0 bar< 4.0 bar (Tryckfall/Pumpfel)
NOx-sensor uppströms (G295)Normal landsvägslast150 – 600 ppmFastfruset 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 NOx sensor assembly with integrated control module, reset SCR adaptation values in the ECU, and clear DTCs.

Need a deeper analysis? Use our advanced fault code analyzer to find likely connections and in-depth guidance.

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Vanliga frågor om dessa felkoder

Vad är den primära orsaken till felkoderna?

The combination of P229F, P20EE, and P2200 indicates NOx sensor element degradation (upstream G295 or downstream G687) on Audi 3.0 TDI V6 engines, resulting in SCR system efficiency fault codes.

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 NOx sensor assembly with integrated control module, reset SCR adaptation values in the ECU, and clear DTCs.