
Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
22 Driving and Operating
Continue to follow the instructions in the
DIC messages. Hold the exhaust brake
switch on the center stack below the climate
controls for more than three seconds, and
then release it, to begin the regeneration
process.
If the EXHAUST BRAKE ON message displays,
then the switch was released too soon.
Press it again to turn off the exhaust brake,
then try again when the DIC message
prompts.
When manual regeneration begins, the
engine speed increases, the engine cooling
fan sound increases, and a DIC message
indicates that cleaning is in progress.
A DIC message will display when cleaning
has completed. The message will remain as
long as cleaning is not necessary. Cleaning
could take up to 30 minutes. Upon
completion, the engine will return to normal
idle, but exhaust components will remain
hot for several minutes. Do not move the
vehicle until the exhaust has had time to
cool. Manual regeneration can be canceled
at any time by pressing the brake pedal or
turning the engine off. Unusual noises may
be heard if regeneration is interrupted.Diesel Exhaust Fluid{
Warning
Avoid getting Diesel Exhaust Fluid (DEF)
on your skin or in your eyes as it could
cause irritation. For more safety,
handling, and storage information, see
the Diesel Exhaust Fluid container label.
Caution
Use only DEF that is GM approved,
or fluid containing the API certified or ISO
22241 label. The use of other fluids could
damage the system, requiring costly
repairs that will not be covered by the
vehicle warranty.
Caution
Do not mix fuel with DEF, and do not put
DEF in the fuel tank. This could lead to
costly repairs that might not be covered
by the vehicle warranty.
Diesel Exhaust Fluid (DEF) is used with diesel
engines to reduce the amount of regulated
emissions produced. Products such as AdBlue are types of DEF, and are approved for use
in the vehicle as long as they have an API
certification label or meet ISO 22241. The
fluid level in the DEF tank must be
maintained for the vehicle to run properly.
DEF is not a fuel additive. DEF should not be
mixed with or added to diesel fuel. DEF
freezes when exposed to temperatures
below
−11 °C (12 °F). For DEF tank capacity
see Capacities and Specifications 082.
It is normal to hear the DEF system purge
fluid back into the tank after the vehicle is
shut off.
Locating Diesel Exhaust Fluid
DEF can be purchased at your dealer.
Additionally, some diesel truck fueling
stations or retailers may have DEF for
purchase. For vehicles with an active OnStar
or connected services plan, OnStar can help
to locate a DEF retailer. See “Customer
Assistance Offices” in the owner’s manual
for phone numbers to assist in contacting a
GM dealer. See Recommended Fluids and
Lubricants 078.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Driving and Operating 23
Filling the DEF Tank
DEF Fill–Van Model Shown, 4-Cylinder
Pickups Similar
The blue DEF cap is behind the fuel/DEF
door. Do not remove the fuel and DEF caps
at the same time. Fill diesel fuel and DEF
independently. Turn the DEF cap
counterclockwise to remove.
In cold conditions DEF can freeze in the DEF
fill pipe opening. If this prevents the filling
of the DEF tank, place the vehicle in a warm
garage overnight.
Fill the DEF tank on level ground and with
the vehicle off. When adding DEF, it is
recommended to fully fill the DEF tank. For DEF tank capacity see
Capacities and
Specifications 082. When adding DEF to an
empty or very low tank, always add at least
7.5L (2 gal) of fluid to release the vehicle
from speed limitation.
When fluid reaches the top of the DEF fill
pipe, stop filling. Do not top off the DEF
tank. If using a bottle or jug to refill DEF,
follow the instructions on the container
label and use a dedicated fill aid.
Caution
Do not overfill the DEF tank and do not
allow DEF to contact the finished surfaces
of the vehicle, as it could damage the
vehicle finish. If DEF is spilled during
filling, wipe any affected surface with a
damp cloth.
Make sure the cap is fully installed.
Push the fuel/DEF door closed.
DEF Low
As the DEF level drops, warnings will
automatically be displayed in the Driver
Information Center (DIC). Select Vehicle
Information in the DIC to view DEF level
status. See Driver Information Center (DIC)
0 10. Refill the DEF tank at the first opportunity
after a low warning indication to avoid
vehicle speed limitations.
It may take some time for the vehicle to
detect that DEF has been added. If there
was a vehicle speed limitation, it will be
removed gradually and it may take several
kilometers/miles for the DIC message to
update.
If DEF is added under freezing conditions,
especially if DEF level is low and frozen, up
to several hours of drive time may be
required to remove the speed limitation.
It is recommended to ensure the DEF tank
level is 30% or higher during winter time.
The DEF range DIC message first displays at
approximately 1 600 km (1,000 mi). This
message appears again at approximately
500 km (300 mi) of remaining range before
the exhaust fluid tank becomes empty.
As the fluid level nears empty, these
messages appear every time the vehicle is
started.
If the DEF low warnings are ignored and the
DEF tank becomes empty, the DIC will
display messages that describe the action
needed and distance until vehicle speed is

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
56 Vehicle Care
.Use engine oil approved to the proper
specification and of the proper viscosity
grade. See“Selecting the Right Engine
Oil” in this section.
.Check the engine oil level regularly and
maintain the proper oil level. See
“Checking Engine Oil” and“When to Add
Engine Oil” in this section.
.Change the engine oil at the appropriate
time. See“Engine Oil Life System” in the
owner’s manual.
.Always dispose of engine oil properly. See
“What to Do with Used Oil” in this
section.
Checking Engine Oil
Check the engine oil level regularly, every
650 km (400 mi), especially prior to a long
trip. The engine oil dipstick handle is a loop.
See Engine Compartment Overview 053 for
the location.
{Warning
The engine oil dipstick handle may be
hot; it could burn you. Use a towel or
glove to touch the dipstick handle.
If a low oil Driver Information Center (DIC)
message displays, check the oil level. Follow these guidelines:
.To get an accurate reading, park the
vehicle on level ground. Check the engine
oil level after the engine has been off for
at least two hours. Checking the engine
oil level on steep grades or too soon after
engine shutoff can result in incorrect
readings. Accuracy improves when
checking a cold engine prior to starting.
Remove the dipstick and check the level.
.If unable to wait two hours, the engine
must be off for at least 15 minutes if the
engine is warm, or at least 30 minutes if
the engine is not warm. Pull out the
dipstick, wipe it with a clean paper towel
or cloth, then push it back in all the way.
Remove it again, keeping the tip down,
and check the level.
When to Add Engine Oil
If the oil is below the cross-hatched area at
the tip of the dipstick and the engine has
been off for at least 15 minutes, add 1 L(1 qt) of the recommended oil and then
recheck the level. See
“Selecting the Right
Engine Oil” later in this section for an
explanation of what kind of oil to use. For
engine oil crankcase capacity, see Capacities
and Specifications 082.
Caution
Do not add too much oil. Oil levels above
or below the acceptable operating range
shown on the dipstick are harmful to the
engine. If the oil level is above the
operating range (i.e., the engine has so
much oil that the oil level gets above the
cross-hatched area that shows the proper
operating range), the engine could be
damaged. Drain the excess oil or limit
driving of the vehicle, and seek a service
professional to remove the excess oil.
See Engine Compartment Overview 053 for
the location of the engine oil fill cap.
Be sure to add enough oil to put the level
somewhere in the proper operating range.
Push the dipstick all the way back in when
through.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Technical Data 81
Technical Data
Vehicle Data
Capacities and Specifications . . . . . . . . . . . 82
Engine Drive Belt Routing . . . . . . . . . . . . . . 84

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
82 Technical Data
Vehicle Data
Capacities and Specifications
The following approximate capacities are given in metric and English conversions. SeeRecommended Fluids and Lubricants078.
Application Capacities
Metric English
Engine Cooling System (Pickup Models)
2.8L 4-Cylinder Engine 10.5 L 11.1 qt
Engine Cooling System (2.8L 4-Cylinder Van Models) Front Heater Core without Fuel Operated Heater (FOH) 13.7 L 14.4 qt
Front Heater Core with Fuel Operated Heater (FOH) 13.9 L 14.7 qt
Front and Rear Heater Core without Fuel Operated Heater (FOH) 15.8 L 16.7 qt
Front and Rear Heater Core with Fuel Operated Heater (FOH) 16.0 L 16.9 qt
Diesel Exhaust Fluid (DEF) Tank* 2.8L 4-Cylinder Pickup Models (LWN) 20.4 L 5.4 gal
2.8L 4-Cylinder Van Models (LWN) 21.0 L 5.5 gal

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Technical Data 83
ApplicationCapacities
Metric English
Engine Oil with Filter
2.8L 4-Cylinder Engine 5.6 L 6.0 qt
*Do not overfill the DEF tank. See Diesel Exhaust Fluid022.
All quantities are approximate. When adding, be sure to fill to the appropriate level, as recommended in this manual. Recheck fluid level
after filling.
Engine cooling system capacity values are based on the entire cooling system and its components.
Engine Specifications
Engine VIN CodeType
2.8L 4-Cylinder Turbo Diesel (LWN Engine) 1L4

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Index 85
IndexA
Accessories and Modifications . . . . . . . . . . . . .52
Air Cleaner/Filter, Engine . . . . . . . . . . . . . . . . . 58
Appearance CareExterior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 58
B
Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Biodiesel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
BrakeExhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
C
Canadian Vehicle Owners . . . . . . . . . . . . . . . . . . . 1
Capacities and Specifications . . . . . . . . . . . . . . 82
CheckEngine Light (Malfunction Indicator) . . . . . 9
Cleaning Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Cluster, Instrument . . . . . . . . . . . . . . . . . . . . . . . . 4
Cold Weather Operation . . . . . . . . . . . . . . . . . . .27
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Covers Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
D
DieselStarting Your Engine . . . . . . . . . . . . . . . . . . . . . 13
Diesel Exhaust Fluid . . . . . . . . . . . . . . . . . . . . . . .22
Diesel Exhaust Fluid (DEF) Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Diesel Particulate Filter . . . . . . . . . . . . . . . . . . . .19
Drive Belt Routing, Engine . . . . . . . . . . . . . . . . 84
Driver Information Center (DIC) . . . . . . . . . . . 10
E
Electrical System Engine Compartment Fuse Block . . . . . . . . 64
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . . 58
Check Light (Malfunction Indicator) . . . . . . 9
Compartment Overview . . . . . . . . . . . . . . . . . 53
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . 60
Drive Belt Routing . . . . . . . . . . . . . . . . . . . . . . 84
Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . . 58
Oil Pressure Gauge . . . . . . . . . . . . . . . . . . . . . . 8
Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Starting Your Diesel . . . . . . . . . . . . . . . . . . . . . 13
Engines Diesel Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Exhaust Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Index 87
S
ServiceAccessories and Modifications . . . . . . . . . . 52
Maintenance Records . . . . . . . . . . . . . . . . . . . 80
Maintenance, General Information . . . . . . 72
Specifications and Capacities . . . . . . . . . . . . . . 82
Starting the Diesel Engine . . . . . . . . . . . . . . . . . 13
Supplement Using . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
T
Top Tier Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
TowingTrailer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Trailer
Towing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Transmission Fluid, Automatic . . . . . . . . . . . . . . . . . . . . . . . . 58
U
Using This Supplement . . . . . . . . . . . . . . . . . . . . .2
V
VehicleCanadian Owners . . . . . . . . . . . . . . . . . . . . . . . . . 1
Personalization . . . . . . . . . . . . . . . . . . . . . . . . . . 11
W
Wait to Start Light . . . . . . . . . . . . . . . . . . . . . . . 10
Water in Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Winter Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16