2020 CHEVROLET LOW CAB FORWARD gas type

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
126 Climate Controls
Ensure that the filter is returned
securely to its original position.
Failure to observe this precaution
can lead to rattling during travel.
The vehicle must not be used with
the filter removed or incorrectly
installed. Failure to observe this
precaution can lead to air
conditioning system damage as a
result of dust, dirt and the like
entering the system.
Removing the Outside Air Filter1. Remove the filter from underthe instrument panel on the
passenger side. While pressing
in the filter lock, on both sides,
pull out the filter.
2. Use a vacuum cleaner or the like to clean dust and dirt from
its surface.
In order to avoid filter damage, hard
brushes should not be used for filter
cleaning.
Installing the Outside Air Filter
Install the filter in the reverse order
to removal.
Ensure that the filter is returned
securely to its original position.
Failure to observe this precaution
can lead to rattling during travel.
The vehicle must not be used with
the filter removed or incorrectly
installed. Failure to observe this
precaution can lead to air
conditioning system damage as a
result of dust, dirt, water, snow, and
the like entering the system.Service
The air conditioning system will not
be able to cool the cab interior
effectively if the refrigerant level is
low. Accordingly, the refrigerant
level must be topped up whenever
necessary.
Please contact your dealer
whenever refrigerant must be
added.
Operation Tips
Operating the air conditioning while
the refrigerant level is too low leads
not only to poor cooling
performance but also to air
conditioning system damage.
This vehicle uses the new
refrigerant HFC134a (R134a) in the
air conditioning system. No other
type of refrigerant can be used. In
order to protect the environment,
care must be taken to ensure that
refrigerant gas is never released
into open air. When refrigerant must
be replaced, therefore, please

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 185
Selective Catalytic Reduction
(SCR) System
The Selective Catalytic Reduction
(SCR) system reduces nitrogen
oxide (NOx) emissions emitted from
a diesel engine. The SCR system
reduces NOx by adding (injecting)
Diesel Exhaust Fluid (DEF) into the
exhaust system and inducing a
reaction converting NOx into water
vapor and nitrogen.
The SCR system consists of the
DEF tank, DEF Control Unit, DEF
Supply Pump and Injector, and the
SCR Catalyst. It is important to keep
a good supply of DEF in the DEF
tank at all times. Monitor the DEF
gauge to be sure the DEF tank level
does not become too low.
If the DEF level becomes too low or
incorrect fluid is added to the DEF
tank, the warning buzzer will sound,
warning and indicator lights will
come on and engine power will be
reduced. If you see these warning
and indicator lights, add DEF as
soon as possible or have your
vehicle serviced as soon as
possible.Continuing to drive for too long after
these lights come on will result in
additional warnings, more engine
power reduction and will eventually
result in a severe vehicle speed
limitation. See
“Diesel Exhaust
Fluid (DEF) Low Level Warning” and
“Incorrect Diesel Exhaust Fluid
(DEF)/SCR System Malfunction
Warnings” later in this section.
{Warning
Do not touch the water that
comes out from the muffler. The
water is mildly acidified due to the
action of oxidation catalyst inside
the muffler. In the event that the
fluid does come into contact with
your skin, completely wash it off
with water. You and others could
be seriously injured. Do not relocate or modify the
exhaust pipe, muffler, DPF, SCR,
or DEF tank, which may affect the
exhaust gas cleaning performance.
If any relocation or modification is
necessary, consult your dealer.
The SCR system continues to
operate for approximately 3 minutes
after the engine control switch is
turned to the "LOCK" position. It is
normal to hear a buzzing type noise
from the DEF supply pump
(mounted on the left side frame rail
behind the cab) during the
shutdown process.
If it is necessary to disconnect the
batteries for any reason, be sure to
wait at least 3 minutes after turning
the engine control switch to the
"LOCK" position. This will allow the
SCR system to properly complete
its shutdown processes. See
Winter
Driving 0142.

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
Vehicle Care 287
occurs, reverse the position of the
tires to equalize wear and get better
tire life.
In addition, when trucks are driven
continuously on high-crown roads,
an increase in air pressure of
35 kPa (5 psi) in the outer tire of a
dual tire operation will prolong outer
tire life. Be sure not to exceed the
inflation pressure limits shown on
the“VIN, Weight Rating, and
Greenhouse Gas (GHG) Emissions
Plate.” SeeVehicle Identification
Number (VIN) 0343.
Wheel and Tire Balancing
Proper tire balancing provides the
best riding comfort and helps to
reduce tire tread wear.
Out-of-balance tires can cause
annoying vehicle vibration and
uneven tire wear, such as cupping
and flat spots. See your authorized
dealer for wheel balancing.
Front End Alignment
Proper front end alignment improves
tire tread mileage. Your vehicle's
front end suspension parts should
be inspected often and aligned when needed. (See the
Maintenance Schedule for more
information.) Improper alignment will
not cause the vehicle to vibrate;
however, improper toe-in alignment
will cause front tires to roll at an
angle that will result in faster tire
wear. Incorrect caster or camber
alignment will cause your front tires
to wear unevenly, and may cause
the vehicle to "pull" to the left or
right.
Tire Traction
A decrease in driving, cornering and
braking traction occurs when water,
snow, ice, gravel or other material is
on the road surface. Driving
practices and vehicle speed should
be adjusted to the road conditions.
When driving on wet or slushy
roads, it is possible for a wedge of
water to build up between the tire
and road surface. This is known as
hydroplaning, and may cause partial
or complete loss of traction, vehicle
control and stopping ability; this
condition is also more likely with
worn tires.
To reduce the chance of traction
loss, follow these tips:
.
Slow down during rainstorms or
when roads are slushy.
. Slow down if the road has
standing water or puddles.
. Replace tires when front tread
depth is 3.2 mm (4/32 in.) and
rear tread depth is 1.6 mm
(2/32 in.).
. Keep tires properly inflated.
Tire Replacement
Recommendations
{Warning
Do not mix different construction
types of tires on your vehicle such
as radial, bias and bias-belted
tires except in emergencies,
because vehicle handling could
be affected and may result in loss
of vehicle control, or personal
injury or death. (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
Vehicle Care 289
Recommended replacement tire for Greenhouse Gas (GHG) emissions
Tire sizeTire makerTire name Rolling
resistance
LT215/85R16E BRIDGESTONE CORPORATION
M779AZ LRRA
THE YOKOHAMA RUBBER CO., LTD. TY213B LRRA
225/70R19.5F BRIDGESTONE CORPORATION
M895Z LRRA
SUMITOMO RUBBER INDUSTRIES, LTD. (DUNLOP) SP688 LRRA
If the original equipment tires are
low rolling tires, it is recommended
to use the LRRA tires shown in the
above table.
Refer to the emission control
identifiers on Greenhouse Gas
(GHG) emission plate for your
original equipment tires. Also,
please refer to “VIN, Weight Rating,
and Greenhouse Gas (GHG)
Emissions Plate” for the location of
the Greenhouse Gas (GHG)
emission plate. See Vehicle
Identification Number (VIN) 0343. Wheel Replacement
Recommendations
Wheels must be replaced if they
become damaged (for example:
bent, heavily rusted, leak air) or if
wheel nuts often become loose. Do
not use bent wheels that have been
straightened and do not use inner
tubes in leaking wheels which are
designed for tubeless tires. Such
wheels may have structural damage
and could fail without warning.
When replacing wheels for any
reason, the new wheels should be
equal in load capacity, diameter, width, offset and mounting types to
those originally installed in your
vehicle.
A wheel of the wrong size or type
may adversely affect wheel and
bearing life, brake cooling,
speedometer/odometer calibration,
stopping ability, headlight aim,
bumper height, vehicle ground
clearance and tire or tire chain
clearance on the body and chassis.
Replacement with "used" wheels is
not advised. They may have been
subjected to harsh treatment or very
high mileage and could fail without
warning.

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
308 Vehicle Care
To wash the vehicle:1. Fully turn on the tap, and wash out the undercarriage and
suspension.
2. Close all openings and wash the cab and cargo body panels
using a neutral detergent.
3. Clean wheels and tires using a brush and detergent.
4. After washing away all remaining detergent, use a
shammy or other clean cloth to
fully remove all moisture and
water droplets
{Warning
Follow the manufacturer's advice
whenever cleaning agents or
other chemicals are used, inside
or outside the vehicle. Some
cleaners may be poisonous or
flammable, and improper use may
cause personal injury or damage.
When cleaning the inside or
outside of the vehicle, do not use
(Continued)
Warning (Continued)
volatile cleaning solvents, such as
acetone, lacquer thinners, enamel
reducers, nail polish removers; or
such cleaning materials as
laundry soaps, bleaches or
reducing agents, except as noted
in the following fabric cleaning
advice on stain removal.
Never use carbon tetrachloride,
gasoline, benzene or naphtha for
any cleaning purpose. Open all
vehicle doors for ventilation when
ANY cleaning agents or other
chemicals are used in the interior.
Overexposure to some vapors
may result in a health problem
that is more likely to occur in
small, unventilated spaces.
You and others could be seriously
injured.
Do not apply water directly in order
to clean the cab interior. Failure to
observe this precaution can result in
malfunction or breakdown of electronic control units and electrical
components, or in rusting of the cab
floor. Do not apply water from a
high-pressure washer nozzle
directly to the electric connectors.
Failure to observe this precaution
can lead to faulty operation of the
electrical system. If an automatic
car or truck-wash is used with
vehicles having dark or metallic
coating, the painted surfaces can be
damaged by the brushes, lose their
luster or be very noticeably
scratched.
Do not direct a large amount of
water at the air inlet openings. Do
not apply water to the engine
compartment or at electrical
components. Failure to observe this
precaution can lead to a poorly
starting and operating engine and
problems in the electrical system.
Ensure that mirrors and the antenna
are retracted before washing the
vehicle.
If an automatic car or truck-wash
must be used, avoid a
high-temperature, high pressure
type machine. Failure to observe

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
314 Vehicle Care
Warning (Continued)
use carbon tetrachloride,
gasoline, benzene or naphtha for
any cleaning purpose.
Open all vehicle doors for
ventilation when ANY cleaning
agents or other chemicals are
used in the interior. Overexposure
to some vapors may result in a
health problem that is more likely
to occur in small, unventilated
spaces.
You and others could be seriously
injured.
The interior of the vehicle must
never be cleaned using acidic or
alkaline solvents, or petroleum
ether, gasoline, and other organic
solvents. Failure to observe this
precaution can result in
discoloration and staining. It should
be noted that certain types of
cleaning products contain these
compounds. Be sure to read
cleaning product labels carefully. Air fresheners (liquid, solid, gel,
or plate types) must not come into
direct contact with, or spill onto,
interior components such as the air
conditioning or audio system.
Compounds contained in these
products can cause discoloration,
staining, or peeling of paint.
Glass cleaners that contain these
compounds must not be used to
clean the inside of the windshield or
window glass. To clean the glass,
wipe it using a cloth wet with warm
or cold water.
To avoid possible permanent
discoloration of light colored seats,
Do not let materials with non-fast
colors come into contact with seat
trim materials until these materials
are totally dry. This includes certain
types of casual clothing, such as
colored denims, corduroys, leathers,
and suedes, as well as decorative
paper.
With the use of modern trim
materials, it is very important that
you use proper cleaning techniques
and cleaners. Failing to do this on
the first cleaning may result in waterspots, spot rings, or setting of stains
or soilage
—all of which are more
difficult to remove in a second
cleaning.
Dust and loose dirt that collect on
interior fabric should be removed
often with a vacuum cleaner or soft
bristle brush. Wipe vinyl or leather
trim regularly with a clean, damp
cloth. Normal trim soils, spots,
or stains can be cleaned with these
cleaners.
Remember these basic steps before
cleaning:
. Remove stains as quickly as
possible before they set.
. Use a clean cloth or sponge,
and change to a clean area
often. A soft brush maybe used
if stains persist.
. Use solvent-type cleaners only
in a well ventilated area: also, do
not saturate the stained area.
. If a ring forms after spot
cleaning, clean the entire area
immediately.