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    P0620, P0625, P0626 Audi 3.0 TDI – LIN-Buss Laddningsregulator Generator Technical Diagnostic Guide

    Diagnostic Priority: High
    Complexity Level: Advanced

    Technical diagnostic guide for AUDI 3.0 TDI Generator covering fault codes P0620, P0625, P0626. Factory live data tolerances and repair procedures.

    Vehicle

    AUDI

    Codes

    3 units

    Analysis Type

    Technical Expert

    Status

    Analyzed

    Technical Analysis

    REF: #79190A

    The fault combination P0620, P0625, P0626 on AUDI 3.0 TDI Generator indicates a validated failure requiring systematic signal and mechanical tolerance checks.

    Expected Symptoms

    Glow plug light flashing and DPF icon illuminated on instrument cluster on AUDI (DTCs: P0620, P0625, P0626)
    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 P0620, P0625, P0626)
    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: P0620)

    Workflow / Methodology

    01

    Verify supply voltage and sensor telemetry for P0620, P0625, P0626 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
    Laddspänning LINMotor igång13.8 – 14.7 V< 12.8 V
    DPF Differenstryck TomgångVarm tomgång 800 rpm3 – 8 hPa> 18 hPa (Igensatt filter)
    Avgastemperatur före DPF (G506)Under regenerering580 – 650 °C< 500 °C (Regenerering avbryts)

    Assessment & Action Proposal

    Technical Recommendation

    Byte av smart spänningsregulator med integrerat LIN-bussgränssnitt på generator. (1:1 Cloning available for ECU/TCU failures).

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

    Start Fault Code Analyzer

    Vanliga frågor om dessa felkoder

    Vad är den primära orsaken till felkoderna?

    The fault combination P0620, P0625, P0626 on AUDI 3.0 TDI Generator indicates a validated failure requiring systematic signal and mechanical tolerance checks.

    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?

    Byte av smart spänningsregulator med integrerat LIN-bussgränssnitt på generator. (1:1 Cloning available for ECU/TCU failures).

    Related Codes

    P0620
    P0625
    P0626

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