P0300 P0171 P0102 VW 2.0 TSI – PCV Valve & Vacuum Leak Diagnostics
Diagnostic guide for P0300, P0171, and P0102 on Volkswagen 2.0 TSI (EA888). Learn how a torn PCV diaphragm causes unmetered air and random misfires.
Vehicle
VOLKSWAGEN
Codes
3 units
Analysis Type
Technical Expert
Status
Analyzed
Technical Analysis
The combination of P0300, P0171, and P0102 on VAG EA888 (1.8/2.0 TSI) indicates a failure in the crankcase ventilation system. A torn PCV diaphragm draws unmetered air directly into the intake manifold, causing a lean condition and rough idle misfires.
Expected Symptoms
System Impact
Potential Fault Sources
Workflow / Methodology
Verify supply voltage and sensor telemetry for P0300, P0171, P0102 on VOLKSWAGEN with multimeter at key ON.
Measure wastegate position feedback voltage at key ON: normal 3.5–3.9 V in closed position.
Smoke-test induction system and boost plumbing at 1.2 bar to pinpoint leaks.
Check crankcase depression with digital manometer at warm idle (-100 to -150 mbar).
Live Data & Mätvärdestoleranser (Är/Bör-värden)
Fabriksgodkända referensvärden vid diagnos och live-avläsning
| Parameter / Signal | Testvillkor | Bör-värde (Normalt) | Avvikelse / Varning |
|---|---|---|---|
| Givarreferensspänning | Tändning på | 4.95 – 5.05 V | < 4.75 V (Kortslutning/Spänningsfall) |
| Signalretur tomgång | Driftstemperatur | Inom fabriksintervall ±5% | Signalkorruption el avbrott |
Assessment & Action Proposal
Technical Recommendation
Install a complete new OEM PCV oil separator with fresh profile gasket. Clean intake runners, clear DTCs, and reset fuel trim adaptations.
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 P0300, P0171, and P0102 on VAG EA888 (1.8/2.0 TSI) indicates a failure in the crankcase ventilation system. A torn PCV diaphragm draws unmetered air directly into the intake manifold, causing a lean condition and rough idle misfires.
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 complete new OEM PCV oil separator with fresh profile gasket. Clean intake runners, clear DTCs, and reset fuel trim adaptations.