heating CHEVROLET LOW CAB FORWARD 2020 User Guide

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
150 Driving and Operating
SymptomCauseCorrective Action Reference
Engine is overheating No engine coolant Add engine coolant
See
Engine
Coolant 0243
Front of radiator is
clogged with dirt Wash clean with tap
waterSee
Exterior Care
0 307
Radiator cap not
sufficiently tightened Make sure it is firmly
tightened or replace the
radiator cap
-
Fan belt loose Adjust the tension or
replace the beltSee
Engine Drive
Belt Routing 0355
Engine coolant dirty
4-
Fan clutch is faulty
4-
Radiator cap dirty or
faulty Clean or replace -
Oil pressure is low Improper engine oil
viscosity
Change to an oil with
proper viscositySee
Engine Oil
0 235
Engine oil level too low Add engine oil See
Engine Oil
0 235
Engine inner
components are faulty
4-
Meter, indicator/warning
lights or switches faulty
4-

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
160 Driving and Operating
Starting the Engine
Do not keep the engine control
switch in the START position for
more than about 10 seconds.
Operating the starter for too long
might cause starter and battery
failure or may result in overheating.
When the engine does not start,
wait for 20 to 30 seconds and then
turn the engine control switch again.
Before starting the engine sit in the
driver seat, check that the parking
brake is firmly engaged, the selector
lever is in the P or N (P is preferred)
position and the shift indicator also
shows P or N, and firmly press the
brake pedal to start the engine.
When stopped on a slope, start the
engine with the selector lever in the
P position. SeeIgnition Positions
0 157.
1. Make sure that the selector lever is in the P or N position
and firmly press the brake
pedal.
2. When the engine control switch
is turned to the ON position,
the wait-to-start light comes on
and it goes out in about
1 second when the engine is
warm, to about 10 seconds
when the engine is cold.
3. After confirming that the wait-to-start light has gone out,
turn the engine control switch
to the START position to start
the engine. Release the engine
control switch as soon as the
engine starts.
4. Do not crank the engine for more than 10 seconds at a
time. If the engine does not
start, wait 20 to 30 seconds
with the engine control switch
in the LOCK or ACC position
before trying to start again. It is normal for the vacuum warning
buzzer to sound for a few seconds
after the engine has started.
After the engine has started, check
to be sure the selector lever is still
in the P position.
This engine has an automatic
warm-up system that increases
engine idle speed and applies the
exhaust brake. Allow sufficient time
to let the engine circulate lubricant
oil before driving. This usually
requires 30 seconds to 2 minutes
depending on ambient conditions.
See
Brake System Warning Light
(Parking Brake Light) 062.
The turbocharged engine should be
started in a way which ensures the
bearings supporting the rotating
parts of the turbocharger are
sufficiently lubricated. Do not race a
cold engine.
At low ambient temperatures, a cold
engine may emit more smoke than
usual.
Do not drive the truck until the
engine has had sufficient time to
circulate the lubricant oil. This

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 161
usually requires 30 seconds to
2 minutes depending on ambient
conditions. This will help reduce
white start-up smoke.
Preheating :Diesel engines are
compression ignited, which makes
them difficult to start when they are
cold because the compression
alone cannot create a temperature
high enough for fuel to ignite.
Preheating means warming the
compressed air inside the
combustion chambers to facilitate
engine starting. Be sure to start the
engine after the wait-to-start light
has gone out.
Start : Do not press the accelerator
pedal at the engine start. The
accelerator opening degree at the
engine start is electronically
controlled.
Warm-up : Do not race the engine
to speed warm-up. Cold Weather Starting
If you plan ahead for cold weather,
starting and driving your vehicle
should be no problem. The following
tips will help ensure good starting in
cold weather.
Oil gets thicker as it gets colder,
which slows down the engine
cranking speed. The diesel engine
functions by the heat of
compression (and glow plugs when
cold), rather than through the use of
spark plugs as in a gasoline engine.
So, your engine must crank faster
than a gasoline engine before it will
start.
To be sure the engine can turn fast
enough to start, use SAE 10W-40
viscosity engine oil when prevailing
temperatures drop below 0 °C
(32 °F). See the oil quality and oil
viscosity recommendations. Using
the proper viscosity oil will make
starting easier down to -23 °C
(-10 °F). When prevailing
temperatures drop below -23 °C
(-10 °F), the engine block heater
may be needed for starting. See
Engine Heater
0163. Maintenance Items to Aid Cold
Weather Starting
Since the basic principle of diesel
engine ignition is based on
compression, the diesel engine is
somewhat harder to start than a
gasoline engine when the
temperature is below freezing.
To help prevent hard starting
problems, special attention should
be given to following normal
maintenance items:
1. Neglecting to have the fuel filter and water separator
serviced can be one of the
major contributors to hard
starting. If water is permitted to
accumulate in the primary filter,
it will freeze and make starting
the engine impossible.
2. Make sure the fuel tank vent is open.
3. Always refuel at the end of a day's operation. Moisture will
condense in an empty tank;
therefore, the tank should be

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
166 Driving and Operating
The cruise set indicator light will
stop flashing and the engine speed
will return to normal.
Engine Checks Before
Operating
Checks Before Operating
Allow the engine to warm up before
placing the engine under heavy load
driving. While the engine is warming
up under light load, the following
checks should be made:1. Observe the red engine oil pressure warning light. The
light should go out when the
engine is running. If it stays on,
shut the engine off and find the
cause.
2. Look at the engine coolant temperature gauge. If the
gauge reaches the H (HOT)
area, stop the engine and find
the cause of the overheating.
3. Check that the battery warning light has gone out. The light
should go off and stay off at
normal idle speeds. If the light does not go out or comes on
during normal operation, have
the charging system checked.
4. Check that the brake low vacuum warning light is out
and that the vacuum buzzer is
not sounding. It is normal for
the warning buzzer to sound
for a few seconds after the
engine starts. If the light and
buzzer remain on, do not drive
the vehicle until the cause has
been found and corrected.
5. Look at the brake system warning light. It should be out
when the parking brake is
released and the engine is
running. If it stays on, it could
mean that the brake fluid level
is low. Check the brake fluid
reservoir. This condition must
be corrected before moving the
vehicle.
{Warning
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.
You and others could be seriously
injured.
Avoid Unnecessary Idling of the
Diesel Engine
If the diesel engine idles too long,
the engine coolant temperature will
fall below the operating range. Low

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
180 Driving and Operating
the selectable (switch) regeneration
required warning light (red) is
displayed on the DIC.
Continued driving 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
Vehicle Messages074.
The time needed to complete
regeneration differs depending on
the outside temperature.
The exhaust brake is activated
during DPF regeneration. The
exhaust brake starting to operate or
being disengaged will produce a
sound, but this does not indicate a
failure.
During regeneration, white smoke
may be temporarily produced from
the exhaust pipe. This results from
combustion of PM, it does not
indicate a failure.
Regeneration is finished earlier
immediately after driving than when
the engine is cold. The engine coolant temperature
may rise during regeneration.
DPF Regeneration during
Prolonged Idling
DPF regeneration may be initiated
automatically during prolonged
idling. If regeneration is initiated, the
regeneration in progress indicator
light (amber) comes on but this is
normal and does not indicate a
failure.
If driving is started or the PTO is
connected during DPF regeneration
by prolonged idling, the selectable
(switch) regeneration required
warning light (amber) comes on and
regeneration is suspended. Perform
Switch regeneration procedure in
order to complete the DPF
regeneration.
Prolonged idling may require more
frequent DPF regeneration.
See
Driver Information Center (DIC)
0 70.Diesel Exhaust Fluid
Diesel exhaust fluid (DEF) is used
exclusively for the selective catalytic
reduction (SCR) system. Be sure to
use only API certified DEF. When
the SCR system detects DEF level
is nearly empty or incorrect fluids
(such as water or low concentrated
DEF.) are added, the SCR system
will turn on warning and indicator
lights and reduce engine power in
progressive stages to encourage
you to have the condition corrected.
Continuing to drive for too long after
these lights come on will eventually
result in a severe vehicle speed
limitation. See Vehicle Messages
0 74
The DEF freezes below −11 °C
(12 °F). The SCR system is
equipped with a heating function
which utilizes the engine coolant, so
the engine can be started even
when DEF is frozen.

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
198 Driving and Operating
Warning (Continued)
When you move the selector lever
into D, 2, 1 or R, creep will cause
the vehicle to move.
When pulling away from a
standstill, you must control the
speed using only the accelerator
pedal. Operate the accelerator
pedal carefully.
Do not operate the selector lever
while pressing the accelerator
pedal. The vehicle may make a
sudden start, possibly causing an
accident.
You and others could be seriously
injured.
When pulling away, visually check
the position of the selector lever.
If you always press the push button
while operating the selector lever,
the lever may occasionally move to
the other gear position against your
intentions. Practice operating the selector lever
between the N and D without
pressing the push button.
Do not operate the selector lever
while pressing the accelerator
pedal. Doing so is dangerous
because the vehicle would
suddenly move.
Do not operate the automatic
transmission at or near stall
condition for more than
five seconds. Stall condition is when
the transmission is in one of the
driving ranges, the engine is running
at high speed, but the drive wheels
are unable to move. This condition
might occur if the vehicle is stuck in
deep sand or is pushing against a
fixed barrier. Operating the
transmission at stall condition will
result in overheating and damage.
Do not hold your vehicle on an
upgrade with the accelerator pedal.
Doing so will result in automatic
transmission overheating and
damage. Use the parking brake or
foot brake to hold the vehicle on an
upgrade.Even if you plan to move only a
short distance, sit in the correct
driving position and make sure you
can firmly press the brake and
accelerator pedals.
When you reverse, you twist to look
rearward so pedal operation
becomes difficult. Firmly press the
brake pedal. Also, practice returning
the selector lever immediately to the
N position after reversing. When
pulling away, visually check the
selector lever position and the shift
indicator.
When the vehicle is stopped, do not
keep pressing the accelerator pedal
with the selector lever in a forward
gear or R position while pressing
the brake pedal. Doing so may
cause a breakdown.
Sit in the correct driving position,
and use your right foot to operate
the brake and accelerator pedals.
To avoid accidentally pressing the
wrong pedal, check the pedal
positions and practice putting your
foot on the desired pedal.

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 201
Driving conditionsSelector lever position
Normal uphill road D (overdrive off switch ON)
Steep uphill, steep slope, mountain
road with many sharp curves 2 or 1
Long uphill road 2
Downhill driving:
Do not overuse the foot brake. This
will cause the brakes to overheat,
reducing their effectiveness. On
long downward slopes or sharp
downhill sections of road, use the
engine brake together with the foot
brakes to control the speed.
When the selector lever is in the D
position, you can drive with the
overdrive off switch ON to allow a
gentle engine brake to be applied.
Push the overdrive off switch to the
ON position at speeds below
101 km/h (63 MPH) to increase
engine braking action when
traveling downgrade. You can increase engine braking by
driving with the selector lever in the
2 position.
To apply a stronger engine brake on
sharp downhill sections, shift the
selector lever to the 1 position when
required.
See
Control of a Vehicle 0130.
Driving at Low Speeds for
Sustained Periods
Any low speed applications such as
sweeper, road marking machinery,
trash collectors, highway striping or
moving, etc. require the following
treatment to prevent the automatic
transmission fluid (ATF) from
overheating:
Select 1 position during low speed
operation under 18 km/h (11 MPH). Select 2 position during low speed
operation under 36 km/h (22 MPH).
See
Automatic Transmission Fluid
Temperature Warning Light 066.
To Stop Your Vehicle 1. To temporarily stop the vehicle, press the brake pedal firmly
while the selector lever is in D.
2. Use the parking brake as required. Press the brake pedal
firmly, and firmly apply the
parking brake.
If the vehicle is stationary for a
long time, move the selector
lever into the N or P position.
If the selector lever is kept in
D, the temperature of the
automatic transmission fluid
increases due to heat from the
torque converter.
To ensure reliable brake application,
be sure to use your right foot to
press the brake pedal.
When leaving the driver's seat,
follow the When Parking Your
Vehicle procedure.

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.