DPF Regeneration

Regeneration is how a DPF cleans itself. The truck raises exhaust temperatures to about 600C, which burns trapped soot into a small amount of ash.

There are three kinds. Passive regen happens on its own during highway driving. Active regen is started by the truck when the filter gets full, and you may see a dash message. Forced regen is triggered with a scan tool at a shop when the filter is too clogged for normal driving to clear.

Let active regens finish. Interrupting them repeatedly with short trips is the number one cause of DPF replacements.

Mike Turner

Red Seal certified heavy duty mechanic with 14 years turning wrenches on Cummins, Powerstroke and Duramax engines across Alberta and Ontario. Mike writes the guides he wishes existed when he was apprenticing.