P2263: Boost-system performance uses an accumulated underboost deviation

P2263 is turbocharger A boost-system performance. Ford’s diesel example uses a desired-minus-actual boost deviation above 35 kPa until a deviation counter reaches 10,000 counts. This accumulated comparison is more specific than labeling every low boost reading as a failed turbocharger.

The controller must be regulating boost

Closed-loop boost control is an entry requirement. Ford lists a typical 100-second monitoring duration for P2263 and requires satisfactory coolant-temperature, manifold-pressure, air-mass, and turbo-position information.

The deviation counter and nominal duration should not be converted into an invented sample rate. The summary provides their listed values but not the complete counter behavior or reset rules. A short isolated dip therefore cannot be assumed to reproduce the accumulated criterion.

Separate this from the low-limit code

P259E on the same page uses much larger desired/actual deviations and shorter engine-specific durations. The two may concern underboost, but their thresholds and persistence logic are different. Preserve which fault actually occurred when selecting the appropriate diagnostic branch.

Useful verification connects boost command, measured pressure, control mode, and the relevant event duration. The entry table contains incomplete upper-limit cells, so this explanation does not invent missing operating bounds. The source also does not identify a leak, actuator fault, or worn turbo as the cause. Those conclusions require the correct vehicle procedure after confirming the documented control discrepancy.

Source and applicability

This explanation follows Ford’s 2023–2024 diesel OBD summary. Match the vehicle’s engine and calibration before applying these monitor values; a generic code alone does not establish fitment. Ford PDF, page 46.