P2187 P0171 P0507 VW 2.0 TSI – System Too Lean at Idle & High Idle RPM Diagnostics
Diagnostic guide for P2187, P0171, and P0507 on Volkswagen 2.0 TSI. Lean fuel trim at idle, higher than expected idle speed, and PCV membrane failure.
Vehicle
VOLKSWAGEN
Codes
3 units
Analysis Type
Technical Expert
Status
Analyzed
Technical Analysis
The combination of P2187, P0171, and P0507 indicates an unmetered air leak isolated to idle conditions on VAG 2.0 TSI engines, caused by a ruptured PCV diaphragm or leaking rear main seal.
Expected Symptoms
System Impact
Potential Fault Sources
Workflow / Methodology
Verify supply voltage and sensor telemetry for P2187, P0171, P0507 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 new genuine PCV oil separator assembly with gasket, reset fuel trim adaptations 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 P2187, P0171, and P0507 indicates an unmetered air leak isolated to idle conditions on VAG 2.0 TSI engines, caused by a ruptured PCV diaphragm or leaking rear main seal.
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 PCV oil separator assembly with gasket, reset fuel trim adaptations in the ECU, and clear DTCs.