Section 194 (Engine Controls - Self-Diagnostics - 6.0L (99P F450/550) Diesel): Summary
WARNING: This page is about a different car, the 2003 Ford Pickup, 2003 Ford F550 Super Duty, 2003 Ford F450 Super Duty, 2003 Ford Excursion, and 2003 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
If no DTCs are present but driveability concern still exists, proceed to TROUBLE SHOOTING - NO CODES - 6.0L DIESEL article for symptom diagnosis or intermittent diagnostic procedures.