P0087 P0088 P229A Audi 2.0 TDI – Bosch CP4 Fuel Pump Failure & Metal Shavings

Diagnostic Priority: High

Complexity Level: Advanced

Diagnostic guide for P0087, P0088, and P229A on Audi TDI. Bosch CP4 high-pressure pump failure, metal glitter in fuel system, and regulator N276.

Vehicle

AUDI

Codes

3 units

Analysis Type

Technical Expert

Status

Analyzed

Technical Analysis

REF: #053D33

The combination of P0087, P0088, and P229A indicates catastrophic Bosch CP4 high-pressure fuel pump failure on VAG 2.0 TDI engines, spreading metal glitter throughout the fuel circuit.

Expected Symptoms

Check engine light illuminated with sudden boost drop under hard acceleration on AUDI (DTCs: P0087, P0088, P229A)

Rough idle and sluggish throttle pickup from a dead stop

Misfiring and hesitation during high-speed highway overtaking (2,500–3,500 RPM)

System Impact

Drivetrain

Engine Control

Emission Control

Potential Fault Sources

01Sticking electronic wastegate actuator or heavy carbon buildup on intake valves (affecting AUDI subsystem for P0087, P0088, P229A)

02Boost control solenoid N75 leakage or split charge air hose

03Ruptured diaphragm in PCV oil separator assembly (logged fault: P0087)

Workflow / Methodology

Verify supply voltage and sensor telemetry for P0087, P0088, P229A on AUDI 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

Mätvärdesblock

Parameter / Signal	Testvillkor	Bör-värde (Normalt)	Avvikelse / Varning
Railtryck Givarsignal (G247)	Tändning på (Motor av)	0.50 V (0 – 5 bar)	> 0.65 V (Givardrift/Spånbeläggning)
Railtryck Är-värde	Tomgång varm motor	250 – 320 bar	Avvikelse > ±15 bar mot Bör-värde
Railtrycksreglerventil N276	Tomgång	16 – 22 % PWM	> 30 % PWM (Högtrycksläckage)

Assessment & Action Proposal

Technical Recommendation

Complete fuel system overhaul: install new CP4 pump, 4 new injectors, fuel rail, lift pump, fuel filter, and thoroughly flush all fuel lines and fuel tank. 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 P0087, P0088, and P229A indicates catastrophic Bosch CP4 high-pressure fuel pump failure on VAG 2.0 TDI engines, spreading metal glitter throughout the fuel circuit.

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?

Complete fuel system overhaul: install new CP4 pump, 4 new injectors, fuel rail, lift pump, fuel filter, and thoroughly flush all fuel lines and fuel tank. Clear DTCs.