AUDI

P0620

P0625

P0626

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

Q: What is the safest way to resolve fault codes P0620, P0625, P0626?

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

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

Verify supply voltage and sensor telemetry for P0620, P0625, P0626 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

Mätvärdesblock

Parameter / Signal	Testvillkor	Bör-värde (Normalt)	Avvikelse / Varning
Laddspänning LIN	Motor igång	13.8 – 14.7 V	< 12.8 V
DPF Differenstryck Tomgång	Varm tomgång 800 rpm	3 – 8 hPa	> 18 hPa (Igensatt filter)
Avgastemperatur före DPF (G506)	Under regenerering	580 – 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).