P0299 OBD II Trouble Code Turbocharger/Supercharger A Underboost Condition

How to quickly diagnose, repair, and info on symptoms and causes of a P0299 DTC code which refers to an underboost condition with the turbo or supercharger system.

Symptoms of P0299 OBD II Trouble Code

  • MIL (Malfunction indicator lamp) illumination
  • Reduced power output from engine, possibly in a "limp" mode
  • Unusual sounds from the engine/turbo

Common Causes of P0299 OBD II Trouble Code

  • Intake (induction) air restriction or leak
  • Failed or damaged turbocharger (sticking, binding, etc.)
  • Faulty boost/charge pressure sensor
  • Faulty wastegate bypass regulator valve (VW)
  • Low fuel pressure condition (Isuzu)
  • Sticking turbo nozzle control solenoid (Isuzu)
  • Faulty injector control pressure (ICP) sensor (Ford)
  • Low oil pressure (Ford)
  • EGR system fault (Ford)
  • Variable geometry turbocharger (VGT) actuator (Ford)
  • VGT vanes sticking (Ford)

Severity of P0299 OBD II Trouble Code

The severity of this code can vary from moderate to severe. If you delay repair of this issue, you can potentially experience more extensive and costly damage.