Possible Causes

• Pinched or disconnected Manifold Absolute Pressure (MAP) sensor hose.
• Leaking intake, hoses or fittings.
• Faulty turbocharger.
• Mechanical engine failure.
• Plugged Green wastegate hose or port charge air intake to turbocharger (Excursion and F250-550).
• Wastegate control solenoid mechanically inoperative (Excursion and F250-550).
• Wastegate actuator (Excursion and F250-550).
• Wastegate valve (Excursion and F250-550)
• Wastegate turbocharger (Excursion and F250-550)
• Leaking intercooler hoses (Excursion and F250-550).

A wastegated turbo is designed to reach maximum boost sooner than a conventional turbo, but over-boosting will cause damage to turbo. PCM will control boost pressure by duty cycle to a control solenoid to maximize boosting performance. When pressure is supplied on Red hose going to actuator (solenoid NOT energized), valve will open, dumping boost. When low or no pressure is on Red hose going to actuator (solenoid is being energized), valve will stay closed.