trailer 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
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 35
Colorado/Canyon Pickup Models–SAE J2807 Compliant
Vehicle Axle Ratio Max. Trailer Wt. GCWR *
Colorado/Canyon Pickup Models –2WD
All 3.42
3 492 kg (7,700 lb) 5 761 kg (12,700 lb)
Colorado/Canyon Pickup Models –4WD
Short Wheelbase Ext. Cab 3.42
3 492 kg (7,700 lb) 5 761 kg (12,700 lb)
Short Wheelbase Crew Cab 3.42
3 447 kg (7,600 lb) 5 761 kg (12,700 lb)
Colorado Pickup –Long Wheelbase
Crew Cab 3.42
3 447 kg (7,600 lb) 5 761 kg (12,700 lb)
Canyon Pickup –Long Wheelbase
Crew Cab 3.42
3 425 kg (7,550 lb) 5 761 kg (12,700 lb)
Colorado ZR2 Models –4WD
All 3.42
2 268 kg (5,000 lb) 4 853 kg (10,700 lb)
*The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and trailer including any
passengers, cargo, equipment, and conversions. The GCWR for the vehicle should not be exceeded.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
36 Driving and Operating
2500/3500 Series Van ModelsVehicle Axle Ratio Max. Trailer Wt.
1GCWR *
G2500 Cargo Van Short Wheelbase 3.42
3 175 kg (7,000 lb) 5 897 kg (13,000 lb)
G2500 Cargo Van Long Wheelbase 3.42
2 767 kg (6,100 lb) 5 897 kg (13,000 lb)
G3500 Cargo Van Short Wheelbase 3.42
2 812 kg (6,200 lb) 5 897 kg (13,000 lb)
G3500 Cargo Van Long Wheelbase 3.42
2 722 kg (6,000 lb) 5 897 kg (13,000 lb)
G2500 Passenger Van Short Wheelbase 3.42
2 858 kg (6,300 lb) 5 897 kg (13,000 lb)
G3500 Passenger Van Short Wheelbase 3.42
2 586 kg (5,700 lb) 5 897 kg (13,000 lb)
G3500 Passenger Van Long Wheelbase 3.42
2 404 kg (5,300 lb) 5 897 kg (13,000 lb)
*The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and trailer including any
passengers, cargo, equipment, and conversions. The GCWR for the vehicle should not be exceeded.
1For Full Box Vans, choose an appropriate hitch and load the truck and trailer within the limits of GCWR, GVWR, and RGAWR.
Van hitch requirements: Trailer tongue weight (10-15% of trailer weight) if under 181 kg (400 lb) use weight carrying hitch. Greater than
181 kg (400 lb) requires weight distribution hitch. Do not exceed 454 kg (1,000 lb).

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
66 Vehicle Care
The vehicle may not be equipped with all of
the fuses, relays, and features shown.Fuses Usage
F1 Traction control module power
F2 Engine control module power
F3 Air conditioning clutch
F4 NOx sensors/Exhaust particulate sensors
F5 Engine control module/ Integrated chassis control
module/Water in fuel
sensor
F6 Front wipers F7 Cargo lamp/Bed lighting
F8 Engine control module miscellaneous
F9 Engine control module
F10 Engine control mod- ule-injectors
F11 Mass airflow sensor
F12 Starter
F13 Traction control module Fuses
Usage
F14 –
F15 –
F16 –
F17 Front axle actuator
F18 –
F19 –
F20 Fuel pump F21 Front blower
F22 Antilock brake system valves
F23 –
F24 Trailer F25 Transfer case electronic control
F26 Antilock brake system pump
F27 Trailer brake control module
F28 Rear window defogger
F29 –
F30 Driver heated seat Fuses
Usage
F31 –
F32 Passenger heated seat
F33 Body control module 3
F34 Integrated chassis control module
F35 –
F36 Center high-mounted stoplamp
F37 Right high-beam headlamp
F38 Left high-beam headlamp
F39 Rear differential lock actuators
F40 Front differential lock actuators/Selective catalytic
reduction power module
wake up
F41 Glow plug module
F42 –
F43 –
F44 Fuel heater F45 Selective catalytic reduction power module heater

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Vehicle Care 67
FusesUsage
F46 Cooling fan clutch F47 Heater crankcase ventilation
F48 Fog lamps
F49 Selective catalytic reduction power module wake up
F50 Trailer parking lamps F51 Horn
F52 –
F53 –
F54 –
F55 –
F56 Washer pump F57 –
F58 –
F59 –
F60 Mirror defogger F61 –
F62 Selective catalytic reduction power module
F63 – Fuses
Usage
F64 Trailer reverse lamps F65 Left trailer stoplamp/ Turnlamp
F66 Right trailer stoplamp/ Turnlamp
F67 Electric power steering
F68 –
F69 Battery regulated voltage control
F70 –
F71 –
F72 –
F73 –
F74 Generator F75 –
Relays Usage
K1 Air conditioning clutch
K2 Starter
K3 Powertrain sensor
K4 Wiper speed Relays
Usage
K5 Wiper control
K6 Cargo lamp/Bed lighting K7 Powertrain
K8 Fuel pump
K9 Front differential lock actuators
K10 Rear differential lock actuators
K11 Center high-mounted stoplamp
K12 Fuel heater
K13 Selective catalytic reduction power
module heater control/
Diesel exhaust fluid
control
K14 Trailer parking lamps K15 Run/Crank
K16 Cooling fan clutch K17 Rear window defogger/ Mirror defogger

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Vehicle Care 69
The vehicle may not be equipped with all of
the fuses, relays, and features shown.Fuses Usage
1 Antilock brake system motor
2 Antilock brake system module
3 Right trailer stoplamp/ Turnlamp
4 –
5 –
6 Fuel system control module/Ignition
7 Body control module 5
8 Body control module 7
9 Body control module 4
10 Instrument cluster 11 Trailer wiring
12 –
13 Display/Mirrors/Rear vision camera
14 Washer
16 Horn Fuses Usage
17 Transmission
18 Air conditioning
19 Engine control module battery
20 Left stop/turn cutaway lamp
21 Left stop/turn trailer lamp
22 Right stop/turn cutaway lamp
23 NOx sensors
24 Diesel fuel pump 25 Auxiliary power outlet
26 Body control module 3 27 Special equipment option
28 Airbag
29 Steering wheel sensor
30 Engine control module/ Glow plug module/
Ignition Fuses Usage
31 Transmission control module/Ignition
32 Transmission control module battery
33 Obstacle detection
34 NOx sensors 35 Fuel operated heater module
36 Fuel system control module battery
41 Transmission control module 2, battery
signal
42 Trailer wiring
43 EV fan clutch
44 Starter solenoid 45 Engine control module, powertrain signal 1
46 DC-AC inverter 47 Cooling fan –low
51 Left high-beam headlamp