CHEVROLET LOW CAB FORWARD 2020 Owner's Manual

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
220 Driving and Operating
At temperatures below 0 °C (32 °F),
it is recommended to switch to Ultra
Low Sulfur Diesel fuel with no
biodiesel content, or to blends with
biodiesel containing less than 5% by
volume. At these extreme cold
temperatures, biodiesel blends
higher than 5% by volume may
cause fuel filter plugging and
system gelling, which can lead to
vehicle operability problems.
Fuels improperly blended for cold
temperature operation may result in
restricted fuel filters and degraded
vehicle performance. The vehicle is
equipped with a fuel heating system
to provide a level of protection
against filter plugging from gelling or
waxing of conventional diesel fuel
and biodiesel blends. If the
operating temperature is far below
the temperature at which gelling or
waxing of the fuel occurs, the
system will not prevent all cases of
filter plugging.
If the vehicle experiences a fuel
filter restriction, the on-board
monitoring system will alert the
driver that the fuel filter requiresservice. The fuel filter, however, will
not prevent all damage caused by
poor quality biodiesel.
Biodiesel Blends
Use biodiesel blends that meet the
ASTM specification D6751.
Retail pumps dispensing blends
containing up to 5% biodiesel (B5)
are not required to be labeled with
the concentration of biodiesel.
Blends up to B5 must meet ASTM
D975 (Grades No. 2-D or No. 1-D
S15 Ultra Low Sulfur Diesel). When
refueling with a biodiesel blend
above B5, one of the following
labels should appear on the
dispenser:
Caution
Do not use blends containing
more than 20% biodiesel. Any
engine, fuel system, or exhaust
after-treatment system damage
would not be covered by the
vehicle warranty.
Blends containing more than 5%
and up to 20% biodiesel must meet
ASTM specification D7467
(Biodiesel blend, B6 - B20) and are
labeled with an orange or blue label.

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 221
To reduce the risk of poor quality
fuel, purchase biodiesel blends from
a fuel supplier or fueling station
which sells BQ-9000 certified
biodiesel. See www.bq-9000.org for
a list of certified marketers.
Biodiesel Blends in Canada
Biodiesel blends that meet the CAN/
CGSB-3.522 specifications up to
20% (B20) can be used. Do not use
biodiesel blends above 20%, as
they may damage the engine and
fuel system.
Cold Weather Operation
Diesel fuel is sensitive to
temperature. All diesel fuel has a
certain amount of paraffin
components, which are high in
energy value and help improve fuel
economy. But, when temperatures
are below -7 °C (20 °F), the paraffin
components begin turning into wax
flakes. If temperatures are low
enough, these flakes can obstruct
the fuel filters and stop fuel from
reaching the engine.At low temperatures, wax flakes are
more likely to form in Number 2-D
fuel than in Number 1-D (or
"winterized" Number 2-D) fuel. For
best operation at temperatures
below -7 °C (20 °F), use Number
1-D, or Number 2-D which has been
blended with Number 1-D for winter
use. When temperatures are
consistently below (or near) -18 °C
(0 °F), use Number 1-D if at all
possible. Bear in mind, however,
that even Number 1-D fuel will form
wax flakes when temperatures are
extremely low.
Do not use home heating oil or
gasoline in your diesel engine;
either may cause engine damage.
The addition of kerosene will not
unplug a filter plugged with wax.
Warming a "waxed" filter to a
temperature of 0 °C to 10 °C (32 °F
to 50 °F) will return the wax to
solution. Filter replacement is not
normally required.
Water in Fuel
During refueling, it is possible for
water (and other contaminants) to
be pumped into your fuel tank along
with the diesel fuel. This can occur if
a service station does not regularly
inspect and clean its fuel tanks, or if
a service station receives
contaminated fuel from its
supplier(s).
To protect your engine from
contaminated fuel, there is a water
separator system on the engine
which allows you to drain excess
water from the fuel.
{Warning
The drained water/diesel fuel
mixture is flammable, and could
be hot. To help avoid personal
injury or death and/or property
damage, do not touch the fuel
coming from the water separator
drain valve, and do not expose
the fuel to open flames or sparks.
(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
222 Driving and Operating
Warning (Continued)
Be sure you do not overfill the
drain pan. Heat (such as from the
engine) can cause the fuel to
expand. If the container is too full,
fuel could be forced out of the
pan. This could lead to a fire and
the risk of personal injury and/or
vehicle damage.
Biocides
In warm or humid weather, fungus,
and/or bacteria may form in diesel
fuel if there is water in the fuel.
Fungus or bacteria can cause fuel
system damage by plugging the fuel
lines, fuel filters or injector. They
can also cause fuel system
corrosion.
If fungus or bacteria has caused fuel
system problems, you should have
your authorized dealer correct these
problems. Then, use a diesel fuel
biocide to sterilize the fuel system
(follow the biocide manufacturer's
instructions). Biocides are available from your dealer, service stations,
parts stores and other automotive
places. See your authorized dealer
for advice on using biocides in your
area and for recommendations on
which biocides you should use.
Smoke Suppressants
Because of extensive testing of
treated fuel versus untreated fuel,
the use of a smoke suppressant
additive is not recommended
because of the greater possibility of
stuck rings and guttered valves,
resulting from excessive ash
deposits.
Water Separator
The purpose of the water separator
is to separate any water from the
fuel that may have formed in the
fuel tank due to condensation.
The water separator is located on
the bottom of the fuel filter.
Caution
Remaining water that is not
discharged from the water
separator could freeze and
damage the vehicle.
If the warning light comes on
while the engine is in operation,
promptly drain the water from the
water separator (fuel filter).
Continuing to drive with the light
remaining on could damage the
fuel injection system. If this
happens, have the vehicle
checked and serviced by the
nearest dealer.
Draining Water from the Fuel
Filter
Clean off any fuel that has adhered
to the vehicle body.
Starting the engine immediately
after draining the water from the fuel
filter requires a little more time than
usual. If the engine does not start in
10 seconds, wait for a while and try
again.

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 223
Fuel will be mixed in the drained
water. Dispose of it in a method
conforming to the regulatory
requirements in your state.
If the water separator (fuel filter)
requires frequent draining, have the
fuel system inspected at your
dealer.
Pre Fuel Filter (Chassis-side)1. Attach a plastic hose to the drain plug (2) on the bottom of
the chassis-side fuel filter and
put the other end of the hose in
a container placed beneath the
filter. 2. Loosen the drain plug and
move the priming pump (1) up
and down by hand between
10 and 20 times.
3. Fully tighten the drain plug (2) and move the priming pump (1)
several times.
Fuel Filter (Engine-side)1. Attach a plastic hose to the drain plug (2) on the bottom of
the engine-side fuel filter (1)
and put the other end of the
hose in a container placed
beneath the filter.
2. Loosen the drain plug andmove the priming pump up and
down by hand between 10 and
20 times.
3. Fully tighten the drain plug and move the priming pump several
times.
4. Test run the engine and check that there are no fuel leaks
from the drain plug of the
engine-side fuel filter. Also
check that the water separator
(fuel filter) warning light
stays off.

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
224 Driving and Operating
Running Out of Fuel
When the Fuel Tank is Empty
When the fuel tank is empty, air will
enter the fuel system, so refueling
alone will not be enough to restart
the engine. Use the following
methods to bleed the fuel system.
Bleeding the Fuel System
Steps for Refueling1. Follow the directions in "Parking Brake Lever" under
Parking Brake 0211. 2. Select the correct fuel (See
"Diesel Fuel Requirement and
Fuel System"). Follow any
posted safety rules. Stand to
the side, never above or
opposite the filler opening.
3. Check that the fuel cap is tight, and see to it that engine oil,
engine coolant in the reservoir,
and washer fluid, etc. are at
proper levels. Then do the
Driver Daily Checklist.
See Owner Checks and Services
0 330.
Driving your vehicle until the fuel
tank is empty may activate the
check engine malfunction indicator
light. You do not need to have your
vehicle checked. After refueling,
perform the following:
. Bleed the fuel system.
. Start, turn off and restart the
engine three or four times.
. The check engine malfunction
indicator light will be cancelled. Before Starting the Engine
1. The priming pump (1) is
located on the outboard side of
the left frame rail, in front of the
batteries. Place a container
beneath the air bleed plug (2)
to receive fuel, and then fully
loosen the plug.
2. Attach a clear hose onto the air bleed plug, direct the clear
hose into a catch pan.
3. Pump the priming pump (1) up/ down for 65 times to get most
of the air bubbles out. Note fuel
was drawn into the filter bowl at
around 40 - 50 times.

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 225
4. Fully retighten the air bleedplug (2) and wipe off any fuel
that may have adhered to the
plug or surrounding area.
5. Continue to operate the pump for 50 times.
6. Start the engine.
7. If the engine does not start, repeat steps 5 and 6 as
necessary until it does start.
After Starting the Engine 1. Without pressing the accelerator pedal, start the
engine.
2. After the engine has started, allow it to idle for about
5 seconds.
3. Fully press the accelerator pedal and increase the engine
speed to the maximum speed
for 10 seconds. (Repeat this
operation several times.) Insufficient air bleeding can result in
faulty engine operation. Be sure,
therefore, to always carry out the
previous steps under "After starting
the engine".
Filling the Tank
Be sure to obey the following
instructions when refueling the
vehicle:
.
Stop the engine and close the
vehicle's doors and windows.
. Keep cigarettes and other
flames away from the vehicle.
. Before opening the fuel tank
filler cap, touch a metallic object
to discharge static electricity
from your body.
. When filling, place the nozzle
deeply into the fuel tank. If you
try to fill more fuel by pulling out
the nozzle from the fuel tank, the
fuel may spill out, thus causing
danger.
. Be sure to wipe off the fuel that
is spilled at refueling.
{Warning
Fuel vapor is highly flammable.
Be careful not to inhale fuel vapor
when refueling the vehicle.
If you have a static charge
buildup on your body while
refueling the vehicle, a spark
caused by its discharge could
ignite the fuel, resulting in burns.
All parts of the refueling
procedure (from opening the fuel
tank filler cap to completing the
refueling and closing the fuel tank
filler cap) must be performed by
the same person.
Other people may be carrying
static electricity. Do not allow
them to approach the fuel filler.
The person performing the
refueling procedure must not
return to the seat in the cab
part-way through the procedure.
(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
226 Driving and Operating
Warning (Continued)
He/she could pick up another
charge of static electricity by
doing so.
Obey all cautions posted in filling
stations.
Type A
In the case of Type A, grip the tab of
the fuel tank filler cap when turning
the cap to open or close.
Type B
After refueling, make sure that the
fuel tank filler cap is tightly closed.
Do not use any fuel tank filler cap
that is not a genuine GM part.
The use of an improper fuel tank
filler cap could cause fuel spillage in
the event of a crash. The use of an
improper fuel tank filler cap could
also affect the fuel system and the
emission control system.
Be sure to wipe off the fuel that is
spilled at refueling.
{Warning
Fuel may be under pressure. Be
sure to slowly open the fuel tank
filler cap. If you open it quickly,
fuel may spurt out. You and
others could be seriously injured.
Caution
Care must be taken when filling
the fuel tank to prevent entry of
dirt and water.

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 227
Conversions and
Add-Ons
Add-On Electrical
Equipment
Installing Electrical Equipment
{Warning
Inappropriate installation or
removal of audio, radio or other
electrical equipment can
adversely affect other electrical
equipment and cause a
breakdown or fire. Be sure to
have electrical equipment
installed or removed by your
dealer. You and others could be
seriously injured.
Do not install any unauthorized
radio set, or any radio set or
antenna that does not comply with
relevant standards. Noise from the
radio set could cause
electromagnetic interference with
the vehicle's electronic equipment and other systems, resulting in a
vehicle breakdown or in a
malfunction of electronic equipment.
Consult your dealer if you wish to
install radio equipment.
Power Take-Off (PTO)
If equipped, the PTO is a device
that is used to provide engine power
to special equipment directly from
the engine or through the
transmission. For details about the
PTO operation, refer to the separate
instruction manual provided by its
maker.
If the optional PTO function is used
for long periods of time, make sure
to regularly check the diesel
particulate filter (DPF) indicator.
Automatic DPF regeneration will not
take place while the PTO function is
active.
1. Engine Speed Control
Switch
2. Main Switch
{Warning
In PTO mode, Cruise Set/Resume
Switch can be used exactly the
same as PTO Engine Speed
Control Switch. Improper
operation of these switches may
cause personal injury or damage.

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
228 Driving and Operating
When Operating the PTO
For operation of special equipment,
see the manufacturer’s instructions.
Installations, or alterations to the
original equipment vehicle or
chassis, as manufactured and
assembled by General Motors, are
not covered by this warranty. The
body company, assembler,
or equipment installer is solely
responsible for warranties on the
body or equipment and any
alterations to any of the parts,
components, systems,
or assemblies installed by GM.
Examples include, but are not
limited to, special body installation,
such as recreational vehicles, the
installation of any non-GM part,
cutting, welding, or the
disconnecting of original equipment
vehicle or chassis parts and
components, extension of the
wheelbase, suspension, and
driveline modifications, and axle
additions.
The engine control module (ECM)
has the ability to accommodate one
of three different PTO modes. Each mode can be programmed to
accommodate many PTO devices.
Optional PTO switches are available
from your dealer to ease installation
of a PTO.
The optional PTO main switch and
PTO engine speed control switch
can be used increase the engine
idle r/min without additional
programming. Pressing the PTO
main switch once will activate the
PTO mode and raise the idle up
speed up to the preset 800 r/min.
Once in PTO mode the PTO engine
speed control switch can be used to
adjust the idle speeds between the
preset 1,300 and 1,700 r/min.
Moving the selector lever from park
or neutral, applying the brake pedal
or releasing the parking brake will
cancel PTO mode and return the
engine idle speed to normal. For
additional details about PTO
programming, contact your dealer.

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 229
Vehicle Care
General Information
General Information . . . . . . . . . . 230
California Proposition65 Warning . . . . . . . . . . . . . . . . . 230
California Perchlorate Materials Requirements . . . . . 230
Accessories and Modifications . . . . . . . . . . . . . . . . 230
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 231
Cab Tilting . . . . . . . . . . . . . . . . . . . . 233
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 234
Engine Cover . . . . . . . . . . . . . . . . . 235
Engine Oil . . . . . . . . . . . . . . . . . . . . 235
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 241
Engine Air Cleaner/Filter . . . . . . 243
Engine Coolant . . . . . . . . . . . . . . . 243
Engine Overheating . . . . . . . . . . 249
Power Steering Fluid . . . . . . . . . 252
Washer Fluid . . . . . . . . . . . . . . . . . 252
Brakes . . . . . . . . . . . . . . . . . . . . . . . 253
Brake Fluid . . . . . . . . . . . . . . . . . . . 258
Battery - North America . . . . . . 259 Fuel Filter . . . . . . . . . . . . . . . . . . . . 260
Rear Axle (Gear Oil Viscosity
Chart) . . . . . . . . . . . . . . . . . . . . . . . 261
Rear Axle (Oil Level Check) . . . . . . . . . . . . . . . . . . . . . . 262
Noise Control System . . . . . . . . 262
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 264
Wiper Blade Replacement . . . . 265
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 267
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 267
Headlamps and Front Turn Signal . . . . . . . . . . . . . . . . . . . . . . . 270
Roofmarker Lamps . . . . . . . . . . . 274
Sidemarker Lamps (Including Turn Signal and Cornering
Lamps) . . . . . . . . . . . . . . . . . . . . . . 274
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 276
License Plate Lamp . . . . . . . . . . 276
Interior Lamps . . . . . . . . . . . . . . . . 277
Electrical System
Electrical System Overload . . . 277
Wheels and Tires
Wheels and Tires . . . . . . . . . . . . . 285
Tire Pressure . . . . . . . . . . . . . . . . . 297
Tire Rotation . . . . . . . . . . . . . . . . . 297
If a Tire Goes Flat . . . . . . . . . . . . 300
Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . 301
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . 305
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . 307
Interior Care . . . . . . . . . . . . . . . . . . 313