Ford F-150 2018 Owner's Manual page 204

Passive Regeneration
In passive regeneration, the exhaust
system temperature and constituents
automatically clean the filter by oxidizing
the soot. Cleaning automatically occurs
during normal vehicle operating conditions
due to driving patterns.
Active Regeneration
Once the diesel particulate filter is full of
exhaust particles, the engine control
module commands the exhaust system to
clean the filter through active regeneration.
Active regeneration requires the engine
computer to raise the exhaust temperature
to eliminate the particles. During cleaning,
the particles convert to harmless gasses.
Once cleaned the diesel particulate filter
continues trapping exhaust particles.
The regeneration process operates more
efficiently when you drive your vehicle at
a constant speed above 30 mph
(48 km/h) and at a steady engine speed
for approximately 20 minutes. The
frequency and duration of regeneration
fluctuates by how you drive your vehicle,
outside air temperature and altitude. For
most driving, regeneration frequency varies
from 100–500 mi (160–805 km) between
occurrences and each occurrence lasts
9–35 minutes. You can usually reduce the
duration of regeneration if you maintain a
constant speed above 30 mph (48 km/h).
When the engine control module detects
that the diesel particulate filter is nearly
full of particulates and you are not
operating your vehicle in a manner to allow
effective automatic regeneration,
messages appear in the information
display as a reminder for you to drive your
vehicle in order to clean the diesel
particulate filter. If you drive your vehicle
in a manner to allow effective automatic
regeneration, the information display
F-150 (TFC) Canada/United States of America, enUSA, Edition date: 201709, Second Printing
Engine Emission Control
201
shows a cleaning exhaust filter message,
which is the normal regeneration process.
You can also choose operator commanded
regeneration to clean the exhaust system
at this point. See Information Messages
(page 123).
If you are not able to drive in a manner that
allows effective automatic active
regeneration or you choose to perform
regeneration of the diesel particulate filter
while at idle, then operator commanded
regeneration would need to be performed.
Operator Commanded Regeneration
(If Equipped)
If your vehicle is operated with significant
stationary operation, low speed drive
cycles less than 25 mph (40 km/h), short
drive cycles, a drive time is less than 10 -
15 minutes or the vehicle does not fully
warm up, passive and active regeneration
may not sufficiently clean the diesel
particulate filter system. Operator
commanded regeneration allows you to
manually start regeneration of the diesel
particulate filter at idle to clean the filter.
If you are not sure whether your vehicle has
this feature, contact an authorized dealer.
When to Carry Out Operator Commanded
Regeneration
You can use the operator commanded
regeneration feature when a message
appears in the information display and you
are not able to drive in a manner that
allows effective automatic active
regeneration or if you choose to manually
start the regeneration of the diesel
particulate filter manually while the vehicle
is idle. See Information Messages (page
123).