2021 CHEVROLET COLORADO stop start

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
14 Driving and Operating
Observe the wait-to-start light. See
Wait-to-Start Light010. This light may
not come on if the engine is warm.
2. If the wait-to-start light is on, wait until this light goes off. Turn the ignition key
to START, then release the ignition key.
The engine will continue to crank until
the engine starts.
The engine has a fast warm-up glow
plug system. The wait-to-start light will
illuminate for a much shorter time than
most diesel engines, due to the rapid
heating of the glow plug system.
Caution
If the wait-to-start light stays on after
starting the vehicle, the vehicle may not
run properly. Have the vehicle serviced
right away.
3. If the engine does not start after 15 seconds of cranking, turn the ignition
off. Wait one minute for the cranking
motor to cool, then try the same steps
again.
If you are trying to start the engine after
you have run out of fuel, follow the steps in
Running Out of Fuel 030. When the engine is cold, let it run for a few
minutes before driving. This lets oil pressure
build up. The engine will sound louder when
it is cold.
For turbo protection, engine power at
speeds above idle may be limited if the
engine is cold. This protection can last up to
a maximum of 40 seconds at extreme cold
coolant and ambient temperatures.
Cold Weather Starting
Use the recommended engine oil when the
outside temperature drops below freezing.
See
Engine Oil 055. When the outside
temperature drops below –18 °C (0 °F), use
of the engine coolant heater is
recommended.
If you experience longer cranking times,
notice an unusual amount of exhaust smoke,
or are at higher elevations (over 2 135 m or
7,000 ft), you may use the engine coolant
heater. See Engine Heater 017.
See Fuel for Diesel Engines 025 for
information on what fuel to use in cold
weather.
If the Diesel Engine Will Not Start
If the vehicle runs out of fuel, see Running
Out of Fuel 030. If the vehicle is not out of fuel, and the
engine will not start:
Turn the ignition key to ON/RUN. After the
wait-to-start light goes off, turn the ignition
key to START.
If the light does not go off, wait a few
seconds, then try starting the engine again.
See your dealer as soon as possible for a
starting system check.
If the light comes on and then goes off and
you know the batteries are charged, but the
engine still will not start, the vehicle needs
service.
If the light does not come on when the
engine is cold, the vehicle needs service.
If the batteries do not have enough charge
to start the engine, see
“Battery”in the
owner’s manual.
Check that the correct engine oil has been
used and changed at appropriate intervals.
If the wrong oil is used, the engine may be
harder to start.
Be sure you are using the proper fuel for
existing weather conditions. See Fuel for
Diesel Engines 025.
If the engine starts, runs a short time, then
stops, the vehicle needs service.

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 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
30 Driving and Operating
The system is not harmed by air in the fuel
lines; however, the engine and/or the FOH
may not start until the fuel system is
primed and the air is removed.
Priming the Fuel System
There is an electric priming pump that will
bring fuel to the engine and eliminate air in
the fuel lines. To prime the engine:1. Correct any condition that caused the loss of prime.
2. Turn the ignition on for 30 seconds. Do not start the engine. The fuel pump will
start priming.
3. Turn the ignition off, then back to start, and crank the engine for 15 seconds.
4. If the engine does not start, repeat Steps 2 and 3 until the engine starts.
If the engine does not start after
repeating Steps 2 and 3 three times, turn
the ignition key off for 60 seconds.
5. Repeat the above steps until the engine starts.
6. If the engine starts, but does not run smoothly, increase the engine speed
slightly. 7. If the engine starts and runs but stalls
again, turn the ignition off for
60 seconds.
8. When the engine starts, let it idle for a few minutes and check the filter for any
leaks.
To Prime the Fuel Operated Heater (FOH)
Fuel Lines (Van Models)
See your dealer or qualified technician if the
FOH fuel lines need to be primed.
Running Out of Fuel
If the engine has stalled due to running out
of fuel, try to restart it: 1. If parked on a level surface, add at least 3.8 L (1 gal) of fuel. Up to 18.9 L (5 gal)
may be needed if parked on a slope.
2. Follow the vehicle fuel system priming procedure earlier in this section to
re-prime the system and restart the
engine.
If the check engine light comes on due to
running out of fuel, it may take a few drive
cycles to clear.
On van models only, the Fuel Operated
Heater (FOH) stops automatically when the
fuel tank volume is less than or equal to 10% of the total tank. The FOH fuel lines
will not need to be primed if the vehicle
runs out of fuel.
Fuel Filter Replacement
Van Models
{Warning
Diesel fuel is flammable. It could start a
fire if something ignites it, and people
could be burned. Do not let it get on hot
engine parts, and keep matches or other
ignition sources away.
The fuel filter is on the driver side, inside
the frame rail.
To replace the fuel filter: 1. Drain any water from the filter. See “Removing Water from the Fuel Filter” in
Water in Fuel 027.
Keep the engine off until the procedure
is completed.
2. Apply the parking brake.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
32 Driving and Operating
4. Remove both filter elements. If there isany dirt on the filter sealing surface,
clean it off.
5. Install the new filter elements and tighten both caps.
6. Use the fuel filter priming procedure earlier in this section to prime the fuel
filter.
7. Start the engine and let it idle for five minutes. Check the fuel filter for
leaks.
8. Reset the fuel filter monitor. See Driver
Information Center (DIC) 010.
Filling the Tank
An arrow on the fuel gauge indicates which
side of the vehicle the fuel door is on. See
Fuel Gauge 07. Do not refill the diesel fuel
and Diesel Exhaust Fluid (DEF) at the
same time.
{Warning
Fuel vapors and fuel fires burn violently
and can cause injury or death.
Follow these guidelines to help avoid
injuries to you and others:
.Read and follow all the instructions on
the fuel pump island.
.Turn off the engine when refueling.
.Keep sparks, flames, and smoking
materials away from fuel.
.Do not leave the fuel pump
unattended.
.Avoid using electronic devices while
refueling.
.Do not re-enter the vehicle while
pumping fuel.
(Continued)
Warning (Continued)
.Keep children away from the fuel
pump and never let children
pump fuel.
.Before touching the fill nozzle, touch a
metallic object to discharge static
electricity from your body.
.Fuel can spray out if the fuel cap is
opened too quickly. This spray can
happen if the tank is nearly full, and is
more likely in hot weather. Open the
fuel cap slowly and wait for any hiss
noise to stop, then unscrew the cap all
the way.
Van Shown, Pickup Similar

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Driving and Operating 33
The green fuel cap is behind a hinged door
on the driver side of the vehicle. The blue
Diesel Exhaust Fluid cap is also behind the
fuel door. Do not remove both caps at the
same time.
Turn the fuel cap counterclockwise to
remove. When refueling, hang the fuel cap
from the hook on the fuel door. Fully insert
and latch the fill nozzle, begin fueling.
{Warning
Overfilling the fuel tank by more than
three clicks of a standard fill nozzle may
cause:
.Vehicle performance issues, including
engine stalling and damage to the fuel
system.
.Fuel spills.
.Under certain conditions, fuel fires.Diesel fuel can foam when filling the tank.
The automatic pump nozzle may shut off,
even if the tank is not full. Wait for the
foaming to stop, and then fill the tank more
slowly. Be careful not to spill fuel. Wait
five seconds after pumping before removing
the fill nozzle. Clean fuel from painted
surfaces as soon as possible. See
Exterior
Care 071.
Reinstall the cap by turning it clockwise
until it clicks. Push the fuel door closed.
{Warning
If a fire starts while you are refueling, do
not remove the fill nozzle. Shut off the
flow of fuel by shutting off the pump or
by notifying the station attendant. Leave
the area immediately.
Caution
If a new fuel cap is needed, be sure to
get the right type of cap from your
dealer. The wrong type of fuel cap may
not fit properly and could damage the
fuel system.
Accidental Refueling with Gasoline
Caution
If the vehicle is accidentally refueled with
gasoline, do not continue driving the
vehicle except to get to a location where
it can be stopped safely. Driving the
vehicle will damage the engine. Tow the
vehicle for service. Have the gasoline
removed from the tank and fuel system.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
44 Driving and Operating
remain at curb idle. A press and release
of +RES on the cruise control will restore
engine rpm to the last PTO set speed. The
PTO system can also be programmed to
return engine rpm to the PTO Standby
Speed setting.
.Press*on the cruise control. The engine
returns to base idle, but the PTO load
relay remains engaged. The PTO indicator
light will blink slowly indicating that a
PTO set speed is still stored in memory.
Activating +RES on the cruise control will
restore engine rpm to the last PTO set
speed.
.Press and release the PTO in-cab switch.
The PTO load relay disengages and the
engine returns to base idle. The PTO
indicator light will turn off, indicating the
PTO load relay is disengaged and the
stored set speed has been cleared from
memory.
Stationary Modes (Preset or Variable) –
Remote Control
To disengage PTO:
.Open the Remote PTO Engine Start/
Shutdown switch. Load relay disengages
and the engine will stop.
.If equipped, press the PTO Emergency
Stop switch. Load relay disengages and
the engine will stop. Refer to the bulletins
in the GM Upfitter Integration website
www.gmupfitter.com for the Power
Take-Off (PTO) operating description and
application guide.
.With the key in the ignition and rotated
to the RUN position, press the brake
pedal. The PTO load relay disengages and
the engine returns to base idle speed. The
operator may drive the vehicle.
Stationary Modes will also disengage if:
.Vehicle movement is detected.
.The parking brake is released.
.The transmission is shifted out of
P (Park).
.The ignition is cycled from RUN to OFF.
.The PTO feedback signal is lost indicating
the load is disengaged if used. See
www.gmupfitter.com.
.Cruise control becomes enabled.
.Timed auto-engine shutdown: This feature
will shut down the engine automatically
after a predefined time. PTO must be
operational for this function to be active.
.Engine shutdown based on critical engine
or PTO system fault conditions: This
feature will shut down the engine when
PTO is operating if a critical engine
condition such as low oil, low oil pressure,
hot engine, hot transmission, low fuel,
or Diesel Particulate Filter regeneration is
detected by the vehicle system. If PTO
operation is continued when critical
engine conditions are present, a horn
chirp warning will occur after 30–
60 seconds. The engine will shut down
two minutes after the horn warning. The
engine can be restarted with the ignition
key or with the Remote PTO engine start
controls. The horn warning and engine
shutdown will again occur if the critical
engine condition is still present.
Resume memory speed is cleared for the
above actions.
When Remote PTO engine starting has been
initialized with the ignition key in the RUN
position, the shift lever will remain locked if
the brake pedal is pressed and a shift from
P (Park) is attempted while the engine is
running and PTO is active (standby mode).
A shift out of P (Park) will not be allowed
until one of the following actions is taken
by the vehicle operator: