2021 CHEVROLET COLORADO towing

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Driving and Operating 13
Driving and Operating
Starting and Operating
Starting the Diesel Engine . . . . . . . . . . . . . . 13
Winter Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Engine Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Fuel Operated Heater (FOH) (VanModels Only) . . . . . . . . . . . . . . . . . . . . . . . . . 19
Parking over Things That Burn . . . . . . . . . . 19
Diesel Particulate Filter
Diesel Particulate Filter . . . . . . . . . . . . . . . . . 19
Diesel Exhaust Fluid
Diesel Exhaust Fluid . . . . . . . . . . . . . . . . . . . . 22
Brakes
Exhaust Brake . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Fuel
Top Tier Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Fuel Additives . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Fuel for Diesel Engines . . . . . . . . . . . . . . . . . 25
Biodiesel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Cold Weather Operation . . . . . . . . . . . . . . . . 27
Water in Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Running Out of Fuel . . . . . . . . . . . . . . . . . . . . 30
Fuel Filter Replacement . . . . . . . . . . . . . . . . . 30
Filling the Tank . . . . . . . . . . . . . . . . . . . . . . . . . 32
Filling a Portable Fuel Container . . . . . . . . 34
Trailer Towing
Trailer Towing . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Conversions and Add-Ons
Power Take-Off (PTO) . . . . . . . . . . . . . . . . . . . 37
Starting and Operating
Starting the Diesel Engine
The diesel engine starts differently than a
gasoline engine.
Caution
If the steering wheel is turned until it
reaches the end of its travel, and is held
in that position while starting the vehicle,
damage may occur to the power steering
system and there may be loss of power
steering assist.
Move the shift lever to P (Park) or
N (Neutral). To restart the engine when the
vehicle is already moving, use
N (Neutral) only.
Caution
Do not try to shift to P (Park) if the
vehicle is moving. If you do, you could
damage the transmission. Shift to P (Park)
only when the vehicle is stopped.
Starting the Engine
1. Turn the ignition key to ON/RUN.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
16 Driving and Operating
.The transmission is shifted out of P (Park)
or N (Neutral).
.The parking brake is released.
.The vehicle speed is not 0 km/h (0 mph).
On vans, when fast idle is active, a FAST
IDLE ON message will be displayed in
the DIC.
Winter Cover
Pickups
Do not use a winter cover on pickups.
Vans
If equipped, the winter cover can be used to
enhance heater performance in extremely
cold conditions below −18 °C (0 °F). The
winter cover installs over the grille and
restricts airflow to the engine compartment.
For vehicles that did not come with a winter
cover, a GM winter cover can be purchased.
See your dealer for additional information.
When the winter cover is in use, the heater,
ventilation, and air conditioning AUTO mode
may not function properly. Use the manual
settings for comfort.
Usage Guidelines
The winter cover should only be used while
operating the vehicle in extremely cold
temperatures or in heavy snow for extended
periods. In these temperatures, the vehicle
does not need a large amount of air to
properly cool the engine. When more
airflow is required to cool the vehicle, the
winter cover should not be used. The
following usage guidelines will allow
adequate airflow for proper radiator and air
cooler performance:
.Do not use the winter cover if towing a
trailer. The vehicle may overheat if the
radiator is covered while towing.
.Do not modify the cover. The winter
cover does not cover some sections of the
front of the vehicle to provide enough
airflow.
.When the winter cover is used, the
outside air temperature display may not
function properly.
.Keep the underside of the winter cover as
clean as possible. Remove monthly or as
necessary and clean away dust and
debris.
.Use only a mild soap to clean. Do not use
harsh soap, strong detergents, or vinyl
protectant/sealant type products as they
may damage the special finish. Allow the
winter cover to dry completely before
reinstalling.
Installation Instructions
When first trying to fit the cover, it may
appear to be undersized but will stretch
during installation to ensure a tight fit. The
initial installation of the cover is best
performed when the winter cover is warm.
1. Open the hood and secure it with the prop rod.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
34 Driving and Operating
Filling a Portable Fuel Container
{Warning
Never fill a portable fuel container while
it is in the vehicle. Static electricity
discharge from the container can ignite
the fuel vapor. You or others could be
badly burned and the vehicle could be
damaged. To help avoid injury to you
and others:
.Dispense fuel only into approved
containers.
.Do not fill a container while it is
inside a vehicle, in a vehicle's trunk, in
a pickup bed, or on any surface other
than the ground.
.Bring the fill nozzle in contact with
the inside of the fill opening before
operating the nozzle. Maintain contact
until filling is complete.(Continued)
Warning (Continued)
.Keep sparks, flames, and smoking
materials away from fuel.
.Avoid using electronic devices while
pumping fuel.
Trailer Towing
When towing at high elevation on steep
uphill grades, consider the following:
Engine coolant at higher elevation will boil
at a lower temperature than at or near sea
level. If the engine is turned off immediately
after towing at high elevation on steep
uphill grades, the vehicle may show signs
similar to engine overheating. To avoid this,
let the engine run while parked (preferably
on level ground) with the transmission in
P (Park) and the parking brake applied for at
least five minutes before turning the engine
off. If the overheat warning comes on, see
Engine Overheating062. Use the following chart to determine the
maximum the trailer can weigh, based upon
your vehicle model and options.
All axles of the trailer must be equipped
with brakes adequate for the intended use.
Trailer braking equipment conforming to
Canadian Standards Association (CSA)
requirement CAN3-D313, or its equivalent, is
recommended.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Driving and Operating 37
See“Trailer Towing” in the owner’s manual
for kingpin weight and trailer tongue weight
information.
Weight of the Trailer Tongue
The tongue weight load (1) of any trailer is
very important because it is also part of the
vehicle weight. The Gross Vehicle
Weight (GVW) includes the curb weight of
the vehicle, any cargo carried in it, and the
people who will be riding in the vehicle as
well as trailer tongue weight. Vehicle
options, equipment, passengers, and cargo
in the vehicle reduce the amount of tongue
weight the vehicle can carry, which will also
reduce the trailer weight the vehicle
can tow.
The trailer tongue weight (1) should be
10-15% of the total loaded trailer (2). For
Vans: The trailer tongue weight (1) can use a
weight carrying hitch for up to 181 kg
(400 lb). Greater than 181 kg (400 lb), a
weight distribution hitch is required with a
maximum of 454 kg (1,000 lb)
Do not exceed the maximum allowable
tongue weight for the vehicle. Choose the
shortest hitch extension that will position
the hitch ball closest to the vehicle. This will
help reduce the effect of trailer tongue
weight on the rear axle.
Trailer rating may be limited by the vehicle's
ability to carry tongue weight. Tongue or
kingpin weight cannot cause the vehicle to
exceed the GVWR (Gross Vehicle Weight
Rating) or the RGAWR (Rear Gross Axle
Weight Rating). See “Total Weight on the
Vehicle's Tires” in the owner’s manual.
After loading the trailer, weigh the trailer
and then the tongue, separately, to see if
the weights are proper. If they are not,
adjustments might be made by moving
some items around in the trailer.
If a cargo carrier is used in the trailer hitch
receiver, choose a carrier that positions the
load as close to the vehicle as possible.
Make sure the total weight, including the carrier, is no more than half of the
maximum allowable tongue weight for the
vehicle or 227 kg (500 lb), whichever is less.
Conversions and Add-Ons
Power Take-Off (PTO)
If equipped, the Power Take-Off (PTO) is a
GM Upfitter integrated system that is used
to create an auxiliary power source for
running add-on equipment, such as salt
spreaders, snow plows, winches, and lift
buckets. The PTO system controls engine
speed to values higher than normal base
idle, PTO load relay engagement, and
remote starting and shutdown of the
engine.
When installing PTO aftermarket equipment,
the PTO wiring and operation
recommendations provided by the service
manual and GM Upfitter documentation
must be strictly followed.
Refer to the bulletins in the GM Upfitter
Integration website www.gmupfitter.com for
the Power Take-Off (PTO) operating
description and application guide.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Vehicle Care 63
Caution
Do not run the engine if there is a leak
in the engine cooling system. This can
cause a loss of all coolant and can
damage the system and vehicle. Have
any leaks fixed right away.
If No Steam Is Coming from the Engine
Compartment
A Driver Information Center (DIC) message,
along with a low coolant condition, can
indicate a serious problem.
If there is an engine overheat warning and
the vehicle does not have a low coolant
condition, and no steam is heard or seen,
the problem may not be too serious.
Sometimes the engine can get a little too
hot when the vehicle:
.Climbs a long hill on a hot day.
.Stops after high-speed driving.
.Idles for long periods in traffic.
.Tows a trailer. See“Driving on Grades”
under “Driving Characteristics and Towing
Tips” in the owner’s manual. If the DIC message comes on with no sign
of steam, try this for a minute or so:
1. In heavy traffic, let the engine idle in N (Neutral) while stopped. If it is safe to
do so, pull off the road, shift to P (Park)
or N (Neutral), and let the engine idle.
2. Turn on the heater to full hot at the highest fan speed and open the window
as necessary.
If the vehicle no longer has the overheat
warning, the vehicle can be driven. Just to
be safe, drive slower for about 10 minutes.
If the warning does not come back on, drive
normally and have the cooling system
checked for proper fill and function.
If the warning continues, pull over, stop, and
park the vehicle right away.
If there is still no sign of steam and the
vehicle is equipped with an engine driven
cooling fan, push down the accelerator until
the engine speed is about twice as fast as
normal idle speed for at least five minutes
while the vehicle is parked. If the warning is
still there, turn off the engine and get
everyone out of the vehicle until it
cools down.
Battery (4-Cylinder Pickup Only)
Pickups with a 4-cylinder diesel engine are
equipped with an AGM (Absorbing Glass
Mat) 12-volt battery. Installation of a
standard 12-volt battery will result in
reduced cold cranking performance. When
using a battery charger on the AGM battery,
use the AGM setting on the charger,
if available, to limit charge voltage to
14.8 volts. Follow the charger manufacturer's
instructions. See “Battery - North America”
in the owner’s manual.

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
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.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
76 Service and Maintenance
Maintenance Schedule Additional
Required Services - Severe12 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)@ @@
Change automatic transmission fluid and filter.@@@
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 - Severe
(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, when driving in climates
with excessive dust, or when off-road driving
or towing a trailer for extended periods.