2020 CHEVROLET LOW CAB FORWARD engine

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
168 Driving and Operating
Warning (Continued)
grass vegetation or stubble
high enough to touch, catch
or collect on its hot exhaust
system.
‐ Parking or idling should be
done only in an area where
there are no combustible
materials under the vehicle.
Failure to follow these
instructions could damage
your vehicle or nearby
property.
Engine Exhaust
Engine Exhaust Emissions
Caution (Carbon Monoxide)
{Warning
Do not breathe exhaust gas
because it contains carbon
monoxide, which by itself has no
color or odor. Carbon monoxide is
a dangerous gas. It can cause
unconsciousness and can be
lethal.
Do not keep the engine running
for any length of time in a place
that is poorly ventilated. It is
particularly dangerous to run the
engine in a garage or other indoor
place that could easily fill with
exhaust gases because you could
suffer carbon monoxide
poisoning.
Inspect the exhaust pipe from
time to time. If you notice any
defect (for example, a damaged
(Continued)
Warning (Continued)
joint, or a hole or crack caused by
corrosion), have checks and
maintenance performed by the
nearest dealer. Continuing to use
the vehicle without having the
defect repaired would be
dangerous because exhaust
gases could get into the cab and
cause carbon monoxide
poisoning.
If at any time you think exhaust
fumes are entering the cab, have
the cause determined and
corrected as soon as possible.
If you must drive under these
conditions, drive only with all
windows fully open. Prevent
carbon monoxide from entering
the cab. The best way is to keep
the engine exhaust system, cab
and cab ventilation system
properly maintained.
(Continued)

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 169
Warning (Continued)
We recommend that the exhaust
system and cab be inspected by
a competent technician:. Each time the vehicle has
an oil change.
. Whenever a change is
noticed in the sound of the
exhaust system.
. Whenever the exhaust
system, underbody or cab is
damaged or becomes
corroded.
To allow proper operation of your
vehicle's ventilation system, keep
the air inlet grille clear of snow,
leaves or other obstructions at all
times. Do not park with the
engine running or idle this vehicle
for more than 10 minutes with the
ventilation system control switch
in the OFF position. Even with the
ventilation system on, running the
engine while parked or stopped (Continued)
Warning (Continued)
for longer periods of time is not
recommended. Entry of carbon
monoxide into the cab is possible
with a poorly repaired, damaged,
or corroded exhaust system or
cab. Do not run the engine in
confined areas (such as garages,
next to a building or near another
stopped vehicles with engine
running) any more than needed to
move the vehicle.
When the vehicle has to be
stopped in an unconfined area
with the engine running for any
more than a few minutes, take the
following steps:
. Adjust the heating or cooling
system to force outside air
into the cab.
. With temperature and outlet
selector knob in any
position:
(Continued)
Warning (Continued)
.Set the air selector lever to
the fresh air position.
. Set the fan speed control
knob to the maximum speed
position.
. Keep the exhaust tailpipe
area clear of snow and
other material to help
reduce the buildup of
exhaust gases under the
vehicle.
This is particularly important when
parked in blizzard conditions. You
and others could be seriously
injured.
See Climate Control Systems 0121
and
Maintenance Schedule 0317.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
170 Driving and Operating
{Warning
Breathing diesel engine exhaust
exposes you to chemicals known
to the State of California to cause
cancer and birth defects or other
reproductive harm.. Always start and operate
the engine in a
well-ventilated area.
. If in an enclosed area, vent
the exhaust to the outside.
. Do not modify or tamper
with the exhaust system.
. Do not idle the engine
except as necessary. For
more information go to
www.P65warnings.ca.gov/
diesel.
See California Proposition
65 Warning 0230 and the back
cover.
Running the Vehicle
While Parked
Caution
To reduce the chance of personal
injury and/or vehicle damage due
to engine overheating, never
leave the engine idling without an
alert driver present. If the engine
should overheat, as indicated by
the engine coolant temperature
gauge, immediate action is
required to correct the condition.
Continued operation of the
engine, even for a short time, may
result in a fire. Do not engage the
exhaust brake while the engine is
idling as this may cause engine
overheating. Avoid Unnecessary Idling of the
Diesel Engine
If the engine idles too long, the
engine coolant temperature will fall
below the operating range. Low
engine operating temperature
causes several conditions that are
harmful to engine operation and life.
Incomplete combustion of fuel in an
engine that is not fully warmed-up
causes crankcase dilution and
forms lacquer and gummy deposits
on valves, pistons, and rings. It also
causes rapid accumulation of
sludge within the engine.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 171
Diesel Particulate
Filter
Diesel Particulate Filter (DPF)
The DPF purifies diesel exhaust
gases of particulate matter (PM). PM
is filtered from the exhaust gas and
collected in the DPF. When PM is
collected to the predetermined level
by the engine control module, the
DPF automatically burns the PM in
a process called regeneration.
Regeneration may not be completed
under certain driving conditions.
If this occurs, the Driver Information
Center (DIC) will provide prompts to
properly complete DPF
regeneration.
The following sections will provide
details on DPF regeneration. Follow
the steps carefully to keep the DPF
in good working order. SeeDriver
Information Center (DIC) 070,
Recommended Fluids and
Lubricants 0339, and Engine Oil
0 235.
{Warning
Exhaust parts and gases become
very hot when the DPF is being
regenerated.
Parking over flammable items
could allow them to touch hot
exhaust parts under your vehicle
and cause them to ignite. Do not
park over papers, leaves, grass
or other things that can burn. You
and others could be seriously
injured.
This content is to restore the
function of the DPF and it is not a
malfunction. However, the check
engine malfunction indicator light
and reduced engine power indicator
light may come on and the power
output may be limited if driving or
power take-off (PTO) operation is
continued for a long time with the
regeneration required warning light
or selectable (switch) regeneration
required warning light (amber/
red) on. This is to prevent the DPF from
being damaged. When operating
PTO during parking, check to
ensure that the regeneration
required warning light or selectable
(switch) regeneration required
warning light (amber/red) on the DIC
is not on.
Engine oil that supports DPF (low
ash oil) is recommended. Use of low
ash oil extends the maintenance
interval of the DPF filter.
Do not modify the DPF or exhaust
pipe. Changing the alignment,
length or diameter of the exhaust
pipe would adversely affect the
exhaust system's exhaust emission
reduction function. If any
modification is necessary to install a
component to the rear of the
vehicle, consult your dealer.
Although the DPF filter automatically
undergoes regeneration (burning of
the accumulated PM) when a
certain amount of PM has
accumulated, driving conditions can
prevent completion of regeneration.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
172 Driving and Operating
The selectable (switch) regeneration
required warning light (amber) will
turn on when regeneration cannot
be completed automatically. Perform
Running or Switch regeneration in
accordance with the proper
procedure. This is to restore DPF
function and is normal.
The exhaust pipe mixes air with the
exhaust gas to lower its temperature
before it leaves the exhaust pipe.
The frequency of regeneration
increases especially under the
following environments:
‐Midwinter.
‐ Continuous low-speed driving for
long hours (The frequency of
regeneration increases
particularly with special
equipment vehicles such as
sweeper vehicles which mainly
travel at low speed. The
frequency of regeneration is
higher as compared to delivery
vehicles which mainly travel at
standard high speed). Automatic regeneration is performed
under normal driving conditions
(DPF soot accumulation status level
5, and in rare cases, may be
performed at continuously
low-speeds for long hours, except
PM level 5); however, the
regeneration required warning light
(amber) may be displayed in the
DIC under the following driving
conditions:
‐
When only low-speed driving at/
under vehicle speed of 15 km/h
(9 MPH) is performed.
‐ When frequent engine start and
stop are performed.
‐ When the engine stops every
time before the engine is
warmed up.
‐ When continuous idling (over
1 hour) is frequently performed.
If the vehicle is stationary with the
engine idling during DPF
regeneration, the exhaust brake or
exhaust throttle operates. Operating
sounds will be heard when the exhaust brake or exhaust throttle is
activated or deactivated. The
sounds do not indicate a fault.
White smoke could be emitted
briefly from the exhaust pipe in the
following situations, but it is not
indicating a fault.
‐
Combustion of PM during DPF
regeneration.
‐ During DPF regeneration of a
new vehicle which has been
driven a certain distance. The
vehicle may not emit white
smoke during its initial operation
when new.
‐ Long continuous idling.
The exhaust brake may
automatically be activated in order
to prevent emission of white smoke
if the engine idles continuously over
an extended period of time.
White smoke may be produced
during switch regeneration; do not
perform switch regeneration in any
poorly ventilated indoor place.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 173
White smoke may be produced
during DPF regeneration when a
new vehicle has been driven a
certain distance, but this is not a
malfunction. The vehicle may not
emit white smoke immediately after
purchase.
DPF PM Accumulation Level
This green display only indicates
DPF soot accumulation status. The
DIC can display the PM
accumulation level in green. The L
indicates Low accumulation of PM
and the H indicates High
accumulation of PM in the DPF.
As PM accumulation increases
inside the DPF, the DIC will display
additional bars increasing from L to
H to show the approximate level of
PM accumulation. SeeDriver
Information Center (DIC) 070. DPF Regeneration Status
This amber display indicates the
DPF is regenerating. During DPF
regeneration, the DIC can display
the status of PM reduction in amber.
The highest accumulation level bar
will be flashing as indication of the
regeneration process.
As PM levels decrease in the DPF
during the regeneration process, the
DIC will decrease the number of
bars from H to L. See
Driver
Information Center (DIC) 070.
Automatic Regeneration of DPF
The DPF will regenerate itself as
part of normal operation.
The engine control module (ECM)
controls this function based on
several factors including hours of
operation and mileage. When
automatic regeneration starts, the
regeneration in progress indicator
light (amber) is displayed on
the DIC.
During regeneration the engine idle
speed will increase and the exhaust
brake may activate when the vehicle
is idling while stopped or parked.
Regeneration is normally completed
in about 20 minutes. See Driver
Information Center (DIC) 070.
{Warning
To prevent fire, ensure that there
is no combustible material near
the muffler, the DPF or the
exhaust pipe. Also, be careful not
to burn yourself on the hot
exhaust gas. You and others
could be seriously injured.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
174 Driving and Operating
The DPF performs regeneration
automatically when a certain
quantity of PM accumulates in the
filter.
Depending upon running conditions,
however, the regeneration may
sometimes not be completed. In this
case, the regeneration required
warning light (amber) will come on,
so promptly operate the emergency
regeneration according to the
Emergency Regeneration
Procedure. This operation recovers
the function of the DPF. It does not
mean that a breakdown has
occurred.
The engine speed may increase
and the exhaust brake may activate
while the vehicle is stopped with the
engine idling. When this occurs, the
DPF is automatically regenerated.
This does not indicate a failure.
The system generates a sound
during the automatic regeneration
and its cancellation. This does not
indicate a failure.DPF SwitchThe DPF switch is used to burn PM
(regenerate the filter). You can
initiate regeneration when the
regeneration required warning light
or selectable (switch) regeneration
required warning light turns on with
short repeated beeps.
Continuing driving without
performing the regeneration will
cause the check engine malfunction
indicator light and reduced engine
power indicator light to come on.
The DPF then must be repaired at
the nearest dealer.
Emergency Regeneration
Procedure
If the regeneration required warning
light (amber) or selectable (switch)
regeneration required warning light
(amber) turns on the DIC, the DPF
could not satisfactorily complete
automatic regeneration and driver
action is required. If the
regeneration required warning light
(Not selectable (switch)
regeneration warning light) is turned
on, you can choose from Running

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 175
regeneration or Switch regeneration
in order to complete the DPF
regeneration.
If the selectable (switch)
regeneration required warning light
turns on, you have to perform
Switch regeneration in order to
complete the DPF regeneration.
If you continue driving too long with
the regeneration required warning
light (amber) or selectable (switch)
regeneration required warning light
(amber) displayed on the DIC
without performing one of the
possible regenerations, the
message will change to red
Regeneration Required warning
light or selectable (switch)
regeneration required warning light.
The red regeneration required
warning light or selectable (switch)
regeneration required warning light
indicates the DPF filter is nearly full
of PM, a condition which may be
damaging to the filter.
DPF regeneration should be
completed immediately if the red
regeneration required warning lightor selectable (switch) regeneration
required warning light is displayed
on the DIC.
Continuing to drive without
performing DPF regeneration will
cause the check engine malfunction
indicator light and reduced engine
power indicator light to come on, an
engine power reduction, and may
cause damage to the DPF filter. See
Driver Information Center (DIC)
0
70.
Running Regeneration Procedure
Use this option for completing DPF
regeneration, if driving conditions
and traffic allow you to maintain a
relatively constant speed above
48 km/h (30 MPH) for about
20 minutes.
Follow the steps below to use
Running regeneration: 1. Determine if road and traffic conditions allow for relatively
constant speeds above
48 km/h (30 MPH). 2. Increase the vehicle speed
above 48 km/h (30 MPH) and
keep a constant speed.
3. When vehicle speed, engine coolant temperature and other
factors are met the engine
control module (ECM) will
begin DPF regeneration and
the regeneration in progress
indicator light (amber) will
appear on the DIC.
4. Continue driving until the regeneration in progress
indicator light (amber) goes off.
When this indicator light goes
off the DPF regeneration is
complete.
See Driver Information Center (DIC)
0 70.
While the vehicle is at a stop with
engine idling, the engine speed
increases.