
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
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
Driving and Operating 21
or see www.gmupfitter.com to contact the
GM Upfitter Integration Group for
assistance.
If equipped, this feature allows for manual
cleaning/regeneration of the DPF when it is
unable to clean itself. It may be necessary
to perform a manual regeneration if driving
conditions—such as extended slow speed,
stop-and-go traffic, extended idles, short
drive cycles, or stationary PTO operation —
prevent DPF self-cleaning.
Manual regeneration can only be used when
the DPF has become at least 90% full. At
100% full, it will attempt to automatically
self-clean if proper driving conditions are
met. The DPF will clean itself if the vehicle
can be driven above 50 km/h (30 mph) for
about 30 minutes.
A Driver Information Center (DIC) message
displays when manual regeneration is
possible.
Scroll through the DIC pages to find the
Exhaust Cleaning menu. Depending on
whether the vehicle has a base or uplevel
cluster, it may be under the Settings menu.
If the vehicle cannot be stopped when the
DIC message first indicates cleaning is
available, automatic self-cleaning may have begun. If conditions cannot be met for
self-cleaning to complete, and manual
regeneration is selected, it may take up to
four minutes for the system to switch to
manual regeneration. When the switch
occurs, a DIC message prompts to start the
cleaning process.
{Warning
Do not leave the vehicle during the
regeneration.
Make sure that there are no flammables
near the muffler, DPF and exhaust pipe
which may result in a fire.
Remember that the temperature of
exhaust gases is high enough to burn
you. You and others could be seriously
injured.
Before starting the manual regeneration,
make sure all of the following safety
conditions are met:
.The vehicle is parked on level ground,
away from any flammable materials.
.The vehicle is parked outdoors, away
from any walls or buildings.
.The vehicle is at least 3 m (10 ft) from
any obstructions or materials that may
combust or melt.
.The shift lever is in P (Park).
.The fuel tank is at least one-eighth full.
.All fluids are at the proper level.
.No diagnostic trouble codes have been
set, and the malfunction indicator lamp is
not on.
.The engine coolant temperature is above
71 °C (160 °F).
After making sure all of the safety
conditions have been met, press the trip
odometer reset stem or
Von the steering
wheel control for at least one second to
select Start on the infotainment display.
Follow the instructions in the DIC messages.
Touch ACCEPT to acknowledge that all of
these safety conditions have been met and
to activate regeneration.
If the infotainment display returns to the
previous screen, then one or more of the
necessary operating conditions has not been
met. If you cannot determine which
condition has not been met, see
www.gmupfitter.com to contact the GM
Upfitter Integration Group for assistance.

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
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