freightliner WALK-IN VAN CHASSIS Operator's Manual page 43

IMPORTANT: Using non-specification fuels or
oils can lead to shortened diesel particulate filter
(DPF) cleaning or replacement intervals. For
example, using CJ-4+ oil with 1.3% sulfated ash
(30% more ash content) may result in the need
for DPF cleaning or replacement 20 to 30%
sooner than would normally be required.
IMPORTANT: See the engine manufacturer's
operation manual for complete details and op-
eration of the ATS.
EPA07 Engines
Engines built between January 1, 2007 and Decem-
ber 31, 2009 are required to meet EPA07 guidelines
for reduced exhaust emissions of particulate matter
and nitrogen oxides (NOx). NOx is limited to just
over 1 gram per brake horsepower hour (g/bhp-hr),
and particulate matter cannot exceed 0.01 g/bhp-hr.
The EPA07 ATS varies according to engine manufac-
turer and vehicle configuration, but the exhaust muf-
fler is replaced by an aftertreatment device (ATD).
Inside the ATD, the exhaust first passes over the die-
sel oxidation catalyst (DOC), then passes through
the diesel particulate filter (DPF), which traps soot
particles. The soot is burned to ash during a process
called regeneration (regen).
EPA10 and Newer Engines
The EPA mandates that all engines built after De-
cember 31, 2009 must reduce the level of emissions
exhausted by the engine to the following levels:
•
Nitrogen Oxides (NOx) – 0.2 g/bhp-hr
•
Particulate Matter (PM) – .01 g/bhp-hr
To meet EPA guidelines, engines that are compliant
with EPA10 and newer regulations use an ATS that
has, in addition to a DOC/DPF device like that used
in an EPA07 ATD, a Selective Catalytic Reduction
(SCR) device to reduce NOx downstream of the en-
gine.
After exhaust gases leave the engine, they flow into
the ATS. First they flow into a two-part ATD, com-
prised of a diesel oxidation catalyst (DOC), and a
diesel particulate filter (DPF). The DPF traps soot
particles, then exhaust heat converts the soot to ash
in the DPF, in a process called regeneration (regen).
The harder an engine works, the better it disposes of
soot. Passive regen occurs when the engine is run-
ning under load and regen occurs without input. If
the engine isn't running hot enough, the electronic
controls may initiate an active regen, whereby extra
fuel is injected into the exhaust stream before the
diesel particulate filter, to superheat the soot trapped
in the filter and reduce it to ash. Both types of regen
occur without driver input.
WARNING
Active regeneration can occur automatically any-
time the vehicle is moving. The exhaust gas tem-
perature could reach 1500°F (816°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 automatic regen, ensure
the exhaust outlets are directed away from struc-
tures, trees, vegetation, flammable materials, and
anything else that may be damaged or injured by
exposure to high heat.
Operating at reduced engine load will allow soot to
accumulate in the DPF. When this occurs, the DPF
lamp illuminates, indicating that a regen must be per-
formed, and the driver must either bring the vehicle
up to highway speed to increase the load, or park
the vehicle and initiate a parked regen. See Parked
Regen, later in this chapter for instructions.
After the exhaust stream passes through the ATD, it
flows through another canister housing the SCR de-
vice. A controlled quantity of diesel exhaust fluid
(DEF) is injected into the exhaust stream, where heat
converts it to ammonia (NH
through the SCR device, where the ammonia gas
reacts with the NOx in the exhaust, to produce harm-
less nitrogen (N ) and water vapor (H
2
exits out of the tailpipe.
ATS Warning Lamps
Warning lamps in the driver's message center alert
the driver of situations with the ATS.
•
An illuminated DPF lamp indicates a regen is
needed. See Fig.
•
A slow, 10-second flashing of the high exhaust
system temperature (HEST) lamp alerts the
driver that a parked regen is in progress, but
the exhaust temperatures are still relatively
Engines
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