Autel MaxiCheck EPB - Manual (Page 8)

6
Regeneration is the DPF‘s way to clear the blockage through
continuously burning it at higher temperatures and allowing the now
harmless produce to escape through the exhaust system. There are
two types of regeneration processes for vehicles.
Passive regeneration
Passive regeneration is an automated regeneration which often occurs
on drives where there is prolonged high exhaust temperatures, for
example, on motorway-type runs. This needs no intervention from the
engine control unit. ECM monitors driving style and selects a suitable
time to employ regeneration. Regeneration continues until ECM
calculates that all the soot has been burned. But sometimes the
required long journey motorway-type trip necessary to complete a
passive regeneration of the DPF system is not attained, the
regeneration fails. So manufacturers have had to adapt the technology
and design an ―active‖ regeneration process controlled by the ECM.
Active regeneration
When the diesel particulate (soot) loading in the DPF reaches a
pre-set limit (normally around 45%), the ECU will make minor
adjustments to the fuel injection timing system which will in turn
increase the exhaust temperatures and help initiate the DPF
regeneration process. This is a smart way of getting a motorway-type
temperature to build up inside the DPF system and begin a full
regeneration to bring the unit back to good health.