Active Regeneration
WARNING: This page is about a different car, the 2012 Ford Pickup, 2012 Ford F550 Super Duty, 2012 Ford F450 Super Duty, and 2012 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
Active regeneration, which is initiated by the PCM, will occur when there is not enough passive regeneration occurring due to vehicle drive patterns. In an active regeneration, the DPF is cleaned by raising the exhaust temperature to a point where the soot is burned away. After the soot is burned off, the exhaust temperature and back pressure (restriction) fall back to normal levels.