freightliner cascadia, Driver Manual, Page: 122 / 238

Regeneration
The harder an engine works, the better it disposes of
soot. If the exhaust temperature is high enough, a
process called
passive regeneration (regen) occurs
as the vehicle is driven normally. However, if the en-
gine isn’t running hot enough, the electronic controls
may initiate an
active regen , whereby extra fuel is
injected into the exhaust stream to superheat and
reduce the soot trapped in the DPF to ash. Active
regen happens only when the vehicle is moving
above a certain speed, determined by the engine
manufacturer. See your engine operation manual for
complete details. Both active and passive regen hap-
pen automatically, without driver input.
WARNING
Active regeneration can occur automatically any-
time the vehicle is moving. The exhaust gas tem-
perature could reach 1500°F (800°C), which is hot
enough to cause a fire, heat damage to objects
or materials, or personal injury to persons near
the exhaust outlet. The exhaust temperature can
remain high even after the vehicle has stopped.
When stopping the vehicle shortly after an auto-
matic regen, ensure the exhaust outlets are di-
rected away from structures, trees, vegetation,
flammable materials, and anything else that may
be damaged or injured by exposure to high heat.
See Regen Switches , below, for instructions on
preventing automatic regen if necessary.
When operating conditions do not allow for ATD filter
cleaning by active or passive regen, the vehicle may
require a driver-activated
parked regen . When this
occurs, the DPF lamp illuminates, indicating that a
regen is required. The driver must either bring the
vehicle up to highway speed to increase the load
(thus starting an active regen), or park the vehicle
and initiate a parked regen. See
Regen Switches ,
below, for instructions on initiating a parked regen.
Regen Switches
The regen request switch, located on the dash, is
used to initiate a parked regen. See
Fig. 12.1 . To
access the regen request switch, lift the guard and
press the yellow button.
Some vehicles may be equipped with a regen inhibit
switch. See
Fig. 12.1 . To stop a regen in progress or
prevent the start of a regen, press the lower half of
the switch. Regen is then delayed until the switch is
no longer active.
NOTE: The regen switch can initiate a parked
regen only when the DPF lamp is illuminated.
WARNING
During parked regen, exhaust temperatures are
very high and could cause a fire, heat damage to
objects or materials, or personal injury to per-
sons near the exhaust outlet.
Before initiating a parked regeneration, make cer-
tain the exhaust outlets are directed away from
structures, trees, vegetation, flammable materi-
als, and anything else that may be damaged or
injured by prolonged exposure to high heat.
To initiate a parked regen, perform the following
steps.
1. Park the vehicle away from all flammable materi-
als, put the transmission in neutral, and set the
parking brake.
2. Start and warm the engine until the coolant tem-
perature is at least 150°F (66°C).
3.
Lift the regen request switch guard and press
and hold the yellow button for five seconds. As
the regen process is initiated, engine rpm in-
creases and the HEST lamp illuminates to indi-
cate extremely high exhaust temperatures.
IMPORTANT: The driver must remain with the
vehicle during the entire regen cycle.
f611157 02/08/2012
NO
RGEN
1
2
1. Regen Request
Switch 2. Regen Inhibit Switch
Fig. 12.1, Regen Request and Inhibit Switches
Emissions and Fuel Efficient Components
12.2