P249F: DPF regeneration spends too little time in closed-loop control

P249F means excessive time to enter closed-loop DPF regeneration control. Ford’s diesel monitor expresses the failure as too little time in closed-loop operation relative to total regeneration time. The permitted amount is a function of the event duration, not a fixed number of seconds published on this page.

The event must be an active regeneration

Ford evaluates the check once per regeneration event. Entry conditions include particulate-filter regeneration mode, engine speed of 1,000–3,500 rpm, coolant at least 70°C, and bounded torque and ambient conditions. Hydrocarbon desorption mode must not be occurring.

The monitor also depends on valid temperature-related inputs. A regeneration record collected with an invalid exhaust-temperature signal does not provide the same basis for interpreting temperature-control participation.

Distinguish control entry from control accuracy

P24A0 on the same page evaluates temperature-controller saturation and desired/actual temperature disagreement. P249F instead concerns how much of the event achieved closed-loop operation. The two observations can guide different questions even though both affect regeneration control.

Useful verification establishes whether a qualified regeneration event occurred and how its control state evolved. The summary does not provide the missing duration map or a universal forced-regeneration procedure. It also does not prove that the DPF itself is blocked or requires replacement. The documented evidence concerns insufficient closed-loop participation and needs the applicable service information for cause isolation.

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 53.