P0299 – Turbo/Supercharger Underboost Condition

Description

The engine control module detects boost pressure lower than the commanded level, indicating a leak, control issue or turbocharger failure.

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Symptoms

  • Weak acceleration
  • Low engine power
  • Check engine light on
  • Possible limp mode

Causes

  • Boost pipe or intercooler leaks
  • Faulty boost control solenoid
  • Damaged turbocharger
  • Faulty boost pressure sensor

Diagnosis

  • Inspect boost pipes for leaks
  • Compare target and actual boost values
  • Test boost control solenoid and wastegate
  • Check turbocharger shaft play and condition

Repair

  • Repair leaking boost pipes
  • Replace solenoid or sensor
  • Rebuild or replace turbocharger
  • Clear codes and perform a full‑load test