Correction don... A passive regen is the normal exhaust temp burning some of the particulates in the DPF. An active regen is when the exhaust temp is increased via diesel fuel/vapors is introduced into the exhaust to drive the temps way up to burn the particulates in the DPF.
Tory the only way to remove ash is to add heat so even a passive regeneration will raise the exhaust temps. Not as high as an active regeneration but higher than normal. Here is a good read on passive and active DPF regenerations link
Don