2020 CHEVROLET LOW CAB FORWARD maintenance schedule

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 8/5/19
2 Introduction
Introduction
The names, logos, emblems,
slogans, vehicle model names, and
vehicle body designs appearing in
this manual including, but not limited
to, GM, the GM logo, CHEVROLET,
and the CHEVROLET Emblem are
trademarks and/or service marks of
General Motors LLC, its
subsidiaries, affiliates, or licensors.
This manual has been prepared to
acquaint you with the operation and
maintenance of your vehicle, and to
provide important safety information.
It includes a Maintenance Schedule
and is supplemented with a
Warranty and Owner Assistance
Information booklet. We urge you to
read these publications carefully.The following recommendations will
help ensure the most enjoyable,
safe, and trouble-free operation of
your vehicle. When it comes to
service, keep in mind that your
commercial truck dealer knows your
vehicle best and is interested in
your complete satisfaction. Your
dealer invites you to return for all of
your service needs both during and
after the warranty period.
Remember, if you have a concern
that has not been handled to your
satisfaction, follow the steps in the
separate Warranty and Owner
Assistance Information booklet. We
thank you for choosing our product,
and want to assure you of our
continuing interest in your motoring
pleasure and satisfaction.
Model Reference
The models covered in this
manual are:
Single Cab:.
4500HD
. 4500XD
. 5500HD
. 5500XD
Crew Cab:
. 4500HD
. 4500XD
. 5500HD
. 5500XD
Litho in U.S.A.
Part No. 84638328 B Second Printing©2019 General Motors LLC. All Rights Reserved.

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
Instruments and Controls 77
Exhaust System Warning Light
EXH. SYSTEM
This light comes on when the SCR
system detects a malfunction or
incorrect DEF. SCR system will turn
on other indicator lights and reduce
engine power in progressive stages
to encourage you to have the
malfunction corrected. Continuing to
drive for too long after this light
turns on will eventually result in a
severe vehicle speed limitation.
If this light turns on, promptly have
the vehicle inspected and serviced
at your dealer. SeeDiesel Exhaust
Fluid 0180.
Refill Diesel Exhaust Fluid
(DEF) Warning Light
REFILL DEF
This message displays and a
warning light appears when the DEF
tank is almost empty. Add DEF as
soon as possible.
Engine power will be reduced and
vehicle speed will be limited when
this light is activated. Failure to
promptly refill the DEF tank will result in a severe vehicle speed
limitation. See
Diesel Exhaust Fluid
0 180.
When DIC ERROR is Displayed
ERROR
If the system has not yet been able
to access maintenance data,
ERROR is shown on the DIC.
If ERROR does not change
automatically to a distance or other
maintenance indication, have your
vehicle serviced at your dealer.
Maintenance Data Indicator
Lights
Maintenance data indicator lights
appear on the DIC when each
maintenance item is selected or
when the next change or service
interval of the item is near or has
been reached.
The distance or time shown is the
remaining or excess of them to /
from the change or service timing.
The positive distance or time shows
the remaining of that and the
negative distance or time shows the excess of that. For the items listed
below, the displayed color will
change from green to amber when
remaining distance is below
1 600 km (1,000 mi) and the screen
is selected.
These screens are also displayed
when the engine control switch
turns to the ON position after above
notification timing. The message
remains on the display until the DIC
selector is pressed once or the
vehicle is started.
The maintenance data function
indicates the distance remaining
before the next scheduled
maintenance. Scheduled
maintenance time is approaching
when the display turns from green
to amber. Have the vehicle checked
and serviced at your dealer as soon
as possible.
The vehicle needs to be maintained
more often if it is driven in severe
conditions.

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
Driving and Operating 213
If the number of notches is not
within the standard value range
below, adjust it to the standard
value. Lever stroke is 6 to 8
notches.
Number of notches before parking
brake is set when lever is pulled
slowly from released position with
pull force of about 147 N (15 kgf/
33 lbs). SeeMaintenance Schedule
0 317 and
Additional Maintenance and Care
0 336.
Exhaust Brake
Exhaust Brake Switch
When turned on, the system
increases the amount of power
absorbed by the engine while
coasting in gear. Whenever slowing
down the vehicle, such as on down
grades, in city traffic or approaching
stop signals, this brake system may
be used.
To turn on the exhaust brake system
while driving, pull the lever
backward. The exhaust brake
indicator light comes on. The
exhaust brake will engage
automatically when the accelerator
pedal is released and vehicle speed
is above 10 km/h (6.5 MPH). The exhaust brake will disengage
when the accelerator pedal or brake
pedal is pressed. Releasing the
pedal reengages the exhaust brake.
Push the lever forward to turn the
exhaust brake off during idling.
{Warning
It is extremely dangerous to apply
the exhaust brake on slippery
roads as the tires can skid.
You and others could be seriously
injured.
Even if the selector lever is placed
in the N position, the exhaust brake
does not disengage until the engine
is warmed up if the warm-up system
is on.

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
232 Vehicle Care
chock the wheels. It would be very
dangerous if the vehicle started
to move.
When performing work on the
electrical system, begin by turning
the engine control switch to the
"LOCK" position, wait at least
3 minutes, and then disconnect the
negative cable from the negative
terminal on battery. If the negative
cable is disconnected within
3 minutes, the engine control
module may malfunction.
When working on the fuel line or
fuel filter, remove the fuel tank filler
cap. The fuel system is under
pressure and the fuel will overspill
unless the pressure is relieved,
possibly leading to combustion or
a fire.
Do not make engine adjustments
yourself. Be sure to consult your
dealer.
Use only appropriate tools.
Oils, brake fluid and engine coolant
have lubrication, cooling and rust
prevention functions. If these liquids
deteriorate through loss orcontamination, it will cause a
decline in the performance of the
parts and such problems as seizure
or malfunctioning. Replenish or
change these liquids when
performing the checks (daily and
periodic checks) as required by the
relevant regulations or in
accordance with the Maintenance
Schedule (when either the specified
driving distance or period of time,
whichever comes first, has expired).
Confirm that all systems and
components are normal after
performing the work.
Do not leave the removed parts or
tools in the engine compartment.
They could damage the equipment if
caught in the belts or other moving
components.
Dirty water, dirt and other impurities
seriously impair the effectiveness of
the oil, grease and fluids, and
damage the parts. Exercise all due
caution to prevent waste or other
refuse from coming in contact with
parts or materials that have been
removed when changing or
replenishing them.Do not step on the engine or climb
onto it. You could cause an engine
failure by, for example, damaging
the cylinder head cover or various
connectors.
Electric Welding
Careless electric welding of vehicle
parts can cause welding current to
flow back through the vehicle’s
ground circuit and damage electrical
and electronic parts so that they do
not function normally. Whenever
electric welding is necessary,
consult 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
236 Vehicle Care
and the oil should be changed
regularly according to the
Maintenance Schedule.
The engine oil performs the
following important functions:
.It prevents engine parts from
becoming worn.
. It cools engine parts.
. It cleans engine parts.
. It seals the combustion
chambers and prevents rust.
Replace the engine oil at regular
intervals.
When particulate matter (PM) has
accumulated to a preset level in the
diesel particulate filter (DPF), the
filter is automatically regenerated
through combustion. To make this
regeneration (combustion) possible,
a small amount of fuel is injected
into the engine combustion chamber
after firing. This causes fuel to
gradually become mixed with the
engine oil, and the engine oil level
may rise beyond the original level.
This does not indicate a malfunction
of the engine.Access to the Engine
Single Cab Model
Access to the engine oil dipstick is
located on the engine left side after
tilting the cab. See Cab Tilting
0 233.
Crew Cab Model
The engine oil dipstick is under the
engine inspection sub cover located
beneath the driver's seat.
Checking the Engine Oil Level
Press the engine oil level check
switch. If engine oil level is low the
red oil pressure warning light will
turn on. If the engine oil level is
above the "OK", the green oil level
indicator will turn on.
The oil level varies while the engine
is running, right after it is stopped,
and on sloping ground. When
checking the oil level, be sure the
vehicle is on level ground while the
engine is cool.

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 239
Change Intervals
The oil and oil filter change intervals
for your engine are based on the
use of recommended oil quality and
viscosity, as well as high-quality
filters such as genuine GM oil filters.
Using oil other than recommended,
or oil and filter change intervals
longer than recommended, could
reduce engine life. Damage to
engines due to improper
maintenance or use of incorrect oil
quality and/or viscosity is not
covered by the new vehicle
warranty.
Your engine was filled with a
high-quality engine oil when it was
built. You do not have to change this
oil before the first recommended
change interval. Oil and filter
change intervals depend on how
you use your vehicle. For
information on the proper oil and
filter change intervals. See
Maintenance Schedule0317. Engine Oil Additives
Engine oils contain a variety of
additives. Your engine should not
need any extra additives if you use
the recommended oil quality and
change intervals.
{Warning
Used engine oil contains harmful
contaminants that have caused
skin cancer in laboratory animals.
Avoid prolonged skin contact.
Clean skin and nails thoroughly
using soap and water–not mineral
oil, fuels or solvents. Launder or
discard clothing, shoes or rags
containing used engine oil.
Engine Oil and Gear Oil
Viscosity Charts
Select appropriate engine oil in
accordance with the table below.
It is also important to select the
viscosity appropriate for the
temperature at which your vehicle
operates. Use the following table for
making correct selections. Engine Oil
Engine oil viscosity (thickness) has
an effect on fuel economy and
cold-weather starting. Lower
viscosity engine oils can provide
better fuel economy; however,
higher temperature weather
conditions require higher viscosity
engine oils for satisfactory
lubrication.
When choosing an oil, consider the
range of temperature your vehicle
will be operated in before the next
oil change. Then, select the
recommended oil viscosity from the
chart.
Do not use any viscosity of oil not
recommended. Such oils could
cause engine 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
240 Vehicle Care
This Engine Oil Viscosity Grade
Chart shows general information.
For this vehicle, oil with *W-40
viscosity is recommended.
Changing the Engine Oil and
Oil Filter
Engine oil and the oil filter are
important factors in engine
performance and lifespan. Be sure
to use only the specified oil and oilfilters. The engine oil level must be
checked and the oil should be
changed regularly according to the
Maintenance Schedule.
Use the indicated oil quantities only
as guidelines when changing the
engine oil. After changing the oil,
make sure the oil is at the required
level. See
Capacities and
Specifications 0349. Failure to use the recommended
engine oil could result in engine or
DPF breakdown, or in poor fuel
efficiency. Be sure to use the
recommended engine oil.
Engine oil change precaution:
.
When adding oil, remove the
dipstick.
. After adding oil, wait for at least
5 minutes before starting the
engine. Be sure to reinstall the
dipstick.
Discarded Parts, Oils and
Other Liquids
When changing oils, filters, engine
coolant or other liquids, be sure to
have a container ready in advance
for their disposal.
Use methods conforming to legal
requirements for discarding or
disposing of parts, oils, filters or
engine coolant after change or
replacement.
Do not dispose of used engine oil,
fuel or any other oil in a careless
manner such as pouring it on the
ground, into sewers, or into streams