Possible Causes
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2003 Ford RV Cutaway, 2003 Ford Pickup, 2003 Ford F550 Super Duty, 2003 Ford F450 Super Duty, and 2003 Ford Excursion. However, it is still accessible from the selected car via links, so may be relevant.
- 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.