maintenance CHEVROLET COLORADO 2021 Duramax Diesel Supplement

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Instruments and Controls . . . . . . . . . . . . . . . . . 3
Driving and Operating . . . . . . . . . . . . . . . . . . . 13
Vehicle Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Service and Maintenance . . . . . . . . . . . . . . . . 72
Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
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,
GMC, the CHEVROLET and GMC Truck
Emblems, COLORADO, CANYON, and
Duramax are trademarks and/or service
marks of General Motors LLC, its
subsidiaries, affiliates, or licensors.
For vehicles first sold in Canada, substitute
the name“General Motors of Canada
Company” for GMC and Chevrolet Motor
Division wherever they appear in this
manual.
This manual describes features that may or
may not be on the vehicle because of
optional equipment that was not purchased
on the vehicle, model variants, country
specifications, features/applications that may
not be available in your region, or changes
subsequent to the printing of this owner’s
manual.
Refer to the purchase documentation
relating to your specific vehicle to confirm
the features. This manual contains information that
pertains to the operation of the diesel
engine. It also contains the Diesel
Maintenance Schedule. The sections in this
manual correspond to the sections in the
owner’s manual. This manual, along with
the owner’s manual, will assist you in the
proper use and maintenance of the vehicle.
Keep this manual in the vehicle for quick
reference.
Canadian Vehicle Owners
A French language manual can be obtained
from your dealer, at www.helminc.com,
or from:
Propriétaires Canadiens
On peut obtenir un exemplaire de ce guide
en français auprès du concessionnaire ou à
l'adresse suivante:
Helm, Incorporated
Attention: Customer Service
47911 Halyard Drive
Plymouth, MI 48170
USA
Litho in U.S.A.
Part No. 84267010 A First Printing©2020 General Motors LLC. All Rights Reserved.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
8 Instruments and Controls
the tank was half full, but it actually took
a little more or less than half the tank's
capacity to fill the tank.
.The gauge moves a little while turning a
corner or speeding up.
.The gauge does not go back to E (Empty)
when the ignition is turned off.
None of these indicate a problem with the
fuel gauge.
For information on how to fill the fuel tank,
see Filling the Tank 032.
Engine Oil Pressure Gauge
4-Cylinder Pickup Models
See “Oil Pressure” under“Driver Information
Center (DIC)” in the owner’s manual.
Metric Van Models
English Van Models
Caution
Lack of proper engine oil maintenance
can damage the engine. Driving with the
engine oil low can also damage the
engine. The repairs would not be covered
by the vehicle warranty. Check the oil
level as soon as possible. Add oil if
required, but if the oil level is within the
operating range and the oil pressure is
still low, have the vehicle serviced.
Always follow the maintenance schedule
for changing engine oil.
The engine oil pressure gauge reads in kPa
(kilopascals) or psi (pounds per square inch)
when the engine is running. Oil pressure
may vary with engine speed, outside
temperature, and oil viscosity.
If readings are outside the normal operating
range, the low oil pressure message may
display on the Driver Information Center
(DIC), or for vehicles without a DIC the oil
pressure light will come on. If the oil
pressure message or light comes on, check
the oil level immediately. Do not operate
the engine with the oil pressure warning
light on or an ENGINE OIL LOW ADD OIL
message displayed.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Instruments and Controls 9
Malfunction Indicator Lamp
(Check Engine Light)
This light is part of the vehicle’s emission
control on-board diagnostic system. If this
light is on while the engine is running, a
malfunction has been detected and the
vehicle may require service. The light should
come on to show that it is working when
the ignition is on with the engine not
running. See“Ignition Positions” in the
owner’s manual.
This light may also come on when the
system has detected a problem with the
Diesel Exhaust Fluid (DEF) management
system. See Diesel Exhaust Fluid 022.
Malfunctions are often indicated by the
system before any problem is noticeable.
Being aware of the light and seeking service
promptly when it comes on may prevent
damage.
Caution
If the vehicle is driven continually with
this light on, the emission control system
may not work as well, the fuel economy
may be lower, and the vehicle may not
run smoothly. This could lead to costly
repairs that might not be covered by the
vehicle warranty.
Caution
Modifications to the engine, transmission,
exhaust, intake, or fuel system, or the
use of replacement tires that do not
meet the original tire specifications, can
cause this light to come on. This could
lead to costly repairs not covered by the
vehicle warranty. This could also affect
the vehicle’s ability to pass an Emissions
Inspection/Maintenance test. See
Accessories and Modifications 052.
When the light is on, a malfunction has
been detected. Diagnosis and service may be
required.
Poor fuel quality can cause inefficient engine
operation and poor driveability, which may
go away once the engine is warmed up. If this occurs, change the fuel brand. It may
require at least one full tank of the proper
fuel to turn the light off. See
Fuel for Diesel
Engines 025.
If the light remains on, see your dealer.
Emissions Inspection and Maintenance
Programs
If the vehicle requires an Emissions
Inspection/Maintenance test, the test
equipment will likely connect to the
vehicle's Data Link Connector (DLC).
The DLC is under the instrument panel to
the left of the steering wheel. Connecting
devices that are not used to perform an
Emissions Inspection/Maintenance test or to
service the vehicle may affect vehicle
operation. See “Add-On Electrical Equipment”
in the owner’s manual. See your dealer if
assistance is needed.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
58 Vehicle Care
engine at extremely low temperatures.
When selecting an oil of the appropriate
viscosity grade, it is recommended to select
an oil of the correct specification. See
“Specification”earlier in this section.
Engine Oil Additives/Engine Oil Flushes
Do not add anything to the oil. The
recommended oils meeting the dexos2
specification are all that is needed for good
performance and engine protection.
Engine oil system flushes are not
recommended and could cause engine
damage not covered by the vehicle
warranty.
What to Do with Used Oil
Used engine oil contains certain elements
that can be unhealthy for your skin and
could even cause cancer. Do not let used oil
stay on your skin for very long. Clean your
skin and nails with soap and water, or a
good hand cleaner. Wash or properly
dispose of clothing or rags containing used
engine oil. See the manufacturer's warnings
about the use and disposal of oil products.
Used oil can be a threat to the environment.
If you change your own oil, be sure to drain
all the oil from the filter before disposal. Never dispose of oil by putting it in the
trash or pouring it on the ground, into
sewers, or into streams or bodies of water.
Recycle it by taking it to a place that
collects used oil.
Engine Oil Life System
The engine oil life system calculates engine
oil life based on vehicle use and displays the
CHANGE ENGINE OIL SOON message when it
is time to change the engine oil and filter.
The oil life system should be reset to 100%
only following an oil change. See
“Engine Oil
Life System” in the owner’s manual.
Automatic Transmission Fluid
When to Check and Change (2.8L
4-Cylinder Engine Pickup Models)
See“Automatic Transmission Fluid” in the
owner’s manual.
When to Check and Change (2.8L
4-Cylinder Engine Van Models)
It is not necessary to check the transmission
fluid level. A transmission fluid leak is the
only reason for fluid loss. If a leak occurs,
take the vehicle to your dealer and have it
repaired as soon as possible. There is a special procedure for checking and
changing the transmission fluid. Because this
procedure is difficult, this should be done at
your dealer. Contact your dealer for
additional information.
Change the fluid and filter at the intervals
listed in
Maintenance Schedule 073 or
Maintenance Schedule 077, and be sure to
use the fluid listed in Recommended Fluids
and Lubricants 078.
Engine Air Cleaner/Filter
2.8L 4-Cylinder Engine Pickup Models
See “Engine Air Cleaner/Filter” in the
owner’s manual.
2.8L 4-Cylinder Engine Van Models
The air cleaner/filter assembly is on the
front of the engine compartment on the
driver side of the vehicle. See Engine
Compartment Overview 053.
When to Inspect/Replace the Engine Air
Cleaner/Filter
For intervals on changing and inspecting the
engine air filter, see Maintenance Schedule
0 73 or
Maintenance Schedule 077.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Vehicle Care 59
How to Inspect/Replace the Engine Air
Cleaner/Filter
Do not start the engine or have the engine
running with the engine air filter housing
open. Before removing the engine air filter,
make sure that the engine air filter housing
and nearby components are free of dirt and
debris. Remove the engine air filter. Lightly
tap and shake the engine air filter (away
from the vehicle) to release dust and dirt.
Inspect the engine air filter for damage, and
replace if damaged. Do not clean the engine
air filter or components with water or
compressed air.
1. Screws
2. Retaining Clips3. Housing Base
4. Housing Cover
5. Turbo Air Duct
To inspect and replace the filter:
1. Remove the two screws (1) and lift the air cleaner/filter housing base (3) to clear
the turbo air duct (5).
2. Unlock the two retaining clips (2) on the sides of the housing cover (4) and on the
housing base and pull the cover off.
3. Remove the air cleaner/filter from the housing base. Take care to dislodge as
little dirt as possible.
4. Clean the air cleaner/filter sealing surface and housing base.
5. Install the engine air cleaner/filter by aligning the arrow on one side of the air
cleaner/filter end cap with the arrow on
top of the housing base.
6. Reinstall the housing cover by aligning the arrow on top of the cover to the
arrow on top of the housing base, and
fasten the two retaining clips.
7. Align the two bushings under the housing base to the guide pins below on
the closure assembly and push the
housing base into place. 8. Reinstall the two screws to secure the
housing base.{Warning
If part replacement is necessary, the part
must be replaced with one of the same
part number or with an equivalent part.
Use of a replacement part without the
same fit, form, and function may result
in personal injury or damage to the
vehicle.
See Maintenance Schedule 073 or
Maintenance Schedule 077 to determine
when to replace the engine air cleaner/filter.
{Warning
Operating the engine with the air
cleaner/filter off can cause you or others
to be burned. Use caution when working
on the engine. Do not start the engine or
drive the vehicle with the air cleaner/
filter off, as flames may be present if the
engine backfires.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
60 Vehicle Care
Caution
If the air cleaner/filter is off, dirt can
easily get into the engine, which could
damage it. Always have the air cleaner/
filter in place when driving.
Cooling System
The cooling system allows the engine to
maintain the correct working temperature.
2.8L 4-Cylinder Engine Pickup Models
See“Cooling System” in the owner’s
manual.
2.8L 4-Cylinder Engine Van Models
1. Coolant Surge Tank
2. Coolant Surge Tank Pressure Cap
3. Engine Cooling Fan (Out of View)
{Warning
An underhood electric fan can start up
even when the engine is not running and
can cause injury. Keep hands, clothing,
and tools away from any underhood
electric fan.
{Warning
Do not touch heater or radiator hoses,
or other engine parts. They can be very
hot and can burn you. Do not run the
engine if there is a leak; all coolant could
leak out. That could cause an engine fire
and can burn you. Fix any leak before
driving the vehicle.
Engine Coolant
The cooling system in the vehicle is
filled with DEX-COOL engine coolant
mixture. See Recommended Fluids and
Lubricants 078 and
Maintenance Schedule 073 or
Maintenance Schedule 077. The following explains the cooling system
and how to add coolant when it is low.
If there is a problem with engine
overheating, see
Engine Overheating 062.
A 50/50 mixture of clean, drinkable water
and DEX-COOL coolant will:
.Give freezing protection down to −37 °C
(−34 °F).
.Give boiling protection up to 129 °C
(265 °F).
.Protect against rust and corrosion.
.Help keep the proper engine temperature.
.Let the warning lights and gauges work
as they should.
What to Use
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain water or
the wrong mixture, the engine could get
too hot but there would not be an
overheat warning. The engine could catch
fire and you or others could be burned.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
72 Service and Maintenance
Service and Maintenance
General Information
General Information . . . . . . . . . . . . . . . . . . . . 72
Maintenance Schedule
Maintenance Schedule . . . . . . . . . . . . . . . . . . 73
Maintenance Schedule . . . . . . . . . . . . . . . . . . 77
Recommended Fluids, Lubricants, and
Parts
Recommended Fluids and Lubricants . . . 78
Maintenance Replacement Parts . . . . . . . . 79
Maintenance Records
Maintenance Records . . . . . . . . . . . . . . . . . . . 80
General Information
This maintenance section applies to vehicles
with a diesel engine. For gasoline engine
vehicles, see the maintenance schedule
section in the owner’s manual.
Your vehicle is an important investment.
This section describes the required
maintenance for the vehicle. Follow this
schedule to help protect against major repair
expenses resulting from neglect or
inadequate maintenance. It may also help to
maintain the value of the vehicle if it is
sold. It is the responsibility of the owner to
have all required maintenance performed.
Your dealer has trained technicians who can
perform required maintenance using genuine
replacement parts. They have up-to-date
tools and equipment for fast and accurate
diagnostics. Many dealers have extended
evening and Saturday hours, courtesy
transportation, and online scheduling to
assist with service needs.Your dealer recognizes the importance of
providing competitively priced maintenance
and repair services. With trained technicians,
your dealer is the place for routine
maintenance such as oil changes and tire
rotations and additional maintenance items
like tires, brakes, batteries, and wiper blades.
Caution
Damage caused by improper maintenance
can lead to costly repairs and may not be
covered by the vehicle warranty.
Maintenance intervals, checks,
inspections, recommended fluids, and
lubricants are important to keep the
vehicle in good working condition.
Do not have chemical flushes that are not
approved by GM performed on the
vehicle. The use of flushes, solvents,
cleaners, or lubricants that are not
approved by GM could damage the
vehicle, requiring expensive repairs that
are not covered by the vehicle warranty.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Service and Maintenance 73
The Tire Rotation and Required Services are
the responsibility of the vehicle owner. It is
recommended to have your dealer perform
these services every 12 000 km/7,500 mi.
Proper vehicle maintenance helps to keep
the vehicle in good working condition,
improves fuel economy, and reduces vehicle
emissions.
Because of the way people use vehicles,
maintenance needs vary. There may need to
be more frequent checks and services. The
Additional Required Services - Normal are for
vehicles that:
.Carry passengers and cargo within
recommended limits on the Tire and
Loading Information label. See“Vehicle
Load Limits” in the owner’s manual.
.Are driven on reasonable road surfaces
within legal driving limits.
.Use the recommended fuel. See Fuel for
Diesel Engines 025.
Refer to the information in the Maintenance
Schedule Additional Required Services -
Normal chart. The Additional Required Services - Severe are
for vehicles that are:
.Mainly driven in heavy city traffic in hot
weather.
.Mainly driven in hilly or mountainous
terrain.
.Frequently towing a trailer.
.Used for high speed or competitive
driving.
.Used for taxi, police, or delivery service.
Refer to the information in the Maintenance
Schedule Additional Required Services -
Severe chart.
{Warning
Performing maintenance work can be
dangerous and can cause serious injury.
Perform maintenance work only if the
required information, proper tools, and
equipment are available. If they are not,
see your dealer to have a trained
technician do the work. See “Doing Your
Own Service Work” in the owner’s
manual.
Maintenance Schedule
See the owner’s manual for other services
and intervals that may be required.
Owner Checks and Services
Check the engine oil level. See Engine Oil
0 55.
Engine Oil Change
When the CHANGE ENGINE OIL SOON
message displays, have the engine oil and
filter changed within the next 1 000 km/
600 mi. If driven under the best conditions,
the engine oil life system may not indicate
the need for vehicle service for up to a year.
The engine oil and filter must be changed at
least once a year and the oil life system
must be reset. Your trained dealer technician
can perform this work. If the engine oil life
system is reset accidentally, service the
vehicle within 5 000 km/3,000 mi since the
last service. Reset the oil life system when
the oil is changed. See Engine Oil Life
System 058.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
74 Service and Maintenance
Extended Idle Use
When the vehicle is used in a way that
requires extended idle time, one hour of use
shall be deemed the same as 33 miles. See
Driver Information Center (DIC)010 for
hourmeter.
Required Services Every 12 000 km/
7,500 mi
.Check engine oil level and oil
life percentage. If needed, change engine
oil and filter, and reset oil life system.
See Engine Oil 055 and
Engine Oil Life System 058.
.Check engine coolant level. See Cooling
System 060.
.Visually check for fluid leaks.
.Inspect engine air cleaner filter. See
Engine Air Cleaner/Filter 058.
.Visually inspect fuel system for damage
or leaks.
.Visually inspect exhaust system and
nearby heat shields for loose or damaged
parts.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Service and Maintenance 75
Maintenance Schedule Additional
Required Services - Normal12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi 60 000 km/37,500 mi
72 000 km/45,000 mi84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi 120 000 km/75,000 mi 132 000 km/82,500 mi
144 000 km/90,000 mi 156 000 km/97,500 mi
168 000 km/105,000 mi 180 000 km/112,500 mi
192 000 km/120,000 mi 204 000 km/127,500 mi 216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Perform Required Services. Check engine oil level and oil
life percentage. Change engine oil and filter, if needed.@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace engine air cleaner filter. (1)@ @@
Drain and fill engine cooling system. (2)@
Visually inspect accessory drive belts. (3)@
Replace timing belt.@
Replace fuel filter. (Pickup) (4)@@@@
Replace fuel filter. (Van) (4)@@@@@
Footnotes—Maintenance Schedule
Additional Required Services - Normal
(1) Or every four years, whichever comes
first. If driving in dusty conditions, inspect
the filter at each oil change or more often
as needed. See Engine Air Cleaner/Filter
0 58. (2)
Or every five years, whichever comes
first. See Cooling System 060.
(3) Or every 10 years, whichever comes first.
Inspect for fraying, excessive cracking,
or damage; replace, if needed. (4)
Or every two years, or when the
CHANGE FUEL FILTER message in the Driver
Information Center (DIC) comes on,
whichever comes first. The fuel filter may
need to be replaced more often based on
biodiesel usage, driving in climates with
severe dust, off-road driving, or towing a
trailer for extended periods.