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2005-2008 AUDI S4
4.2L V8•AWD•AUTOMATIC•gas•BHF
2 active safety recalls on this vehicle — view recalls
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Repairs0Labor498Torque3171Fluid10DTC1087Battery1Maintenance0Recalls2
P3000moderate severityPowertrain

Turbo/Supercharger Boost Control Module Performance

on 2005-2008 Audi S4 4.2L V8 · AWD

What this code means

The PCM detected the turbo/supercharger boost control module is not responding correctly to commanded boost levels. The module regulates wastegate or bypass valve position to control boost pressure.

Symptoms

  • Check Engine Light
  • Reduced boost pressure
  • Loss of power under acceleration
  • Turbo lag increased
  • Poor fuel economy

Common causes

  • Faulty boost control module
  • Wastegate actuator failure
  • Vacuum/pressure line leak
  • Corroded module connector
  • PCM communication error

Diagnostic steps

  1. Read freeze frame data and boost PIDs
  2. Command boost control module through scan tool
  3. Inspect vacuum and pressure lines to wastegate
  4. Check boost control module connector and wiring
  5. Measure actual vs commanded boost pressure

Repair notes

Replace boost control module or repair wiring. Verify wastegate actuator operation after repair.

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