2021 CHEVROLET COLORADO lock

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Driving and Operating 17
2. Hook the five J-clips to the bottom edgeof the grille.
3. Hook the top center J-clip by the hood latch. 4. Attach the metal hooks, one each at the
top corners.
5. To remove the winter cover, reverse Steps 1–4.
Engine Heater
{Warning
Do not plug in the engine block heater
while the vehicle is parked in a garage or
under a carport. Property damage or
personal injury may result. Always park
the vehicle in a clear open area away
from buildings or structures.
If equipped, the engine heater can provide
easier starting in cold weather conditions at
or below −18 °C (0 °F). The engine heater
should be plugged in at least four hours
before starting.
To Use the Engine Heater
1. Turn off the engine.

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
24 Driving and Operating
limited. For the DEF warning light symbol,
seeDiesel Exhaust Fluid (DEF) Warning Light
0 10.
DEF Quality Poor
Use only DEF that is GM approved, or fluid
containing the API certified or ISO 22241
label.
DEF has an expiration date. If the system
detects poor quality, or contaminated or
diluted DEF, the DIC message will display
along with distance until vehicle speed is
limited.
The speed limitation will occur in a series of
steps with the final speed limitation being
8 km/h (5 mph) along with a flashing
warning light and chimes.
Adding fresh DEF to the system may resolve
the problem after several kilometers/miles
of driving, depending on several factors.
If the DIC message persists, see your dealer
or additional DIC messages may display.
Service DEF System
If a problem occurs with the DEF system, a
DIC message displays along with distance
until vehicle speed is limited. The speed limitation will occur in a series of
steps with the final speed limitation being
8 km/h (5 mph) along with a flashing
warning light and chimes.
In some cases, this message will clear itself,
indicating that the DEF system was able to
correct the condition. If the DIC message
persists, see your dealer or additional DIC
messages may display.
Service Emission System
If a problem occurs with the vehicle
emission system, a DIC message displays
along with distance until vehicle speed is
limited. The speed limitation will occur in a
series of steps with the final speed
limitation of 88 km/h (55 mph) and chimes.
In some cases, this message will clear itself,
indicating that the emission system was
able to correct the condition. If the DIC
message persists, see your dealer or
additional DIC messages may display.
Brakes
Exhaust Brake
The exhaust brake can be used to enhance
the vehicle brake system and reduce brake
lining wear.Downshifts may be automatically selected
to increase engine speed, which increases
the effectiveness of the exhaust brake. The
number of downshifts selected is
determined by the length of time the brakes
are applied and the rate the vehicle is
slowing. The system delivers the correct
amount of braking to assist in vehicle
control. The heavier the vehicle load, the
more active the engine exhaust brake will
be. Use of the exhaust brake will help
maintain vehicle speed when used with
cruise control. See
“Cruise Control”in the
owner’s manual.
Automatic downshifts will not occur if the
vehicle is in Range Selection Mode. See
“Manual Mode” in the owner’s manual.
The exhaust brake only activates when the
transmission torque converter is locked. This
can vary based on vehicle speed, gear,
and load.
To activate the system, press the switch on
the center stack.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
28 Driving and Operating
{Warning
Diesel fuel containing water is still
combustible. You or others could be
burned. If the fuel needs to be drained,
keep sparks, flames, and smoking
materials away from the mixture.
Caution
Water in the diesel fuel can corrode
internal components of the fuel system
and lead to severe damage. It can also
support fungus or bacteria growth, which
can damage the fuel system and Fuel
Operated Heater (FOH), if equipped. Even
with a diesel fuel biocide, the fuel system
may still need to be cleaned. Your dealer
can advise of the appropriate solution.
If the fuel tank needs to be purged to
remove water, see your dealer or a
qualified technician. Improper purging can
damage the fuel system and block
the FOH.
Water in Fuel Troubleshooting
If the WATER IN FUEL SERVICE REQUIRED
message comes on:Problem Recommended
Action
Message displays
but goes off during
the ignition cycle. The fuel filter is
partially filled with
water. Drain the
water as soon as
possible. See
"Removing Water
from the Fuel Filter"
following.
Message displays
and stays on. Drain the fuel filter
immediately. If no
water can be
drained, and the
temperature is
below freezing, then
water may be
frozen in the filter.
Move the vehicle to
a warm location to
thaw the water,
then drain the fuel.
If water still does
not drain, see your
dealer. Problem
Recommended
Action
Immediately after
refueling, message
displays and
stays on. A large amount of
water is in the fuel
tank. Drain the fuel
filter immediately.
If the message stays
on or comes back
on without
refueling, then fuel
tank purging is
required. See your
dealer. If the
message displays
and the engine
stalls or runs rough,
do not drive until
the water
contaminated fuel is
drained.
Caution
Driving with this message on can damage
the fuel injection system and the engine.
If the message comes on right after a
(Continued)

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Driving and Operating 29
Caution (Continued)
refuel, water was pumped into the fuel
tank. Turn off the engine and drain the
water immediately.
Removing Water from the Fuel Filter
To drain water:1. Turn the engine off and apply the parking brake.
Van
Pickup
2. Place a container under the filter drain valve. The filter drain valve is on the
bottom of the fuel filter. The filter drain
valve is under the vehicle on the driver
side, inside the frame rail.
3. For van models, open the drain valve by turning it counterclockwise. Allow the
filter to drain until all of the water has
been removed. Close the valve.
For pickup models, open the fuel filter
cap by turning it two to three turns.
Allow the filter to drain until all of the
water has been removed. Close the cap
hand tight. 4. Properly dispose of the water
contaminated fuel.
5. Start the engine and let it run for a few minutes. During the draining process, air
may have entered the fuel system. If the
engine stalls, the fuel system may need
to be primed. See “Fuel Priming”
following.
Fuel Priming
For the fuel system to work properly, the
fuel lines must be full of fuel. If air gets in,
the fuel lines need to be primed before
operating the vehicle and the Fuel Operated
Heater (FOH).
If air is present, the following may have
happened:
.The vehicle ran out of fuel.
.The fuel filter was removed.
.The fuel lines were removed or
disconnected.
.The fuel filter water drain valve was
opened while the engine was running.
.The FOH pump and FOH fuel lines were
removed or disconnected.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Driving and Operating 31
3. Remove the filter element cap by turningit counterclockwise.
4. Remove the filter element. If there is any dirt on the filter sealing surface, clean
it off.
5. Install the new filter element and o-ring.
6. Reinstall and tighten the filter cap to the housing.
7. Use the fuel filter priming procedure to prime the fuel filter. See “Fuel Priming”
in Water in Fuel 027.
8. Start the engine and let it idle for five minutes. Check the fuel filter and air
bleed valve for leaks.
9. Reset the fuel filter monitor. See Driver
Information Center (DIC) 010. If the van Fuel Operated Heater (FOH) (if
equipped) is not working, the FOH line
requires priming. See your dealer for service.
See
Fuel Operated Heater (FOH) (Van Models
Only) 019.
Pickup 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 in front of the fuel tank. 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.
3. There are two caps under the filter. Clean the fuel filter area before removing
these two filter caps.
Caution
Failure to cover the fuel filter with a
clean cloth to keep out debris when
replacing may cause dirt to get into the
engine. This could cause engine damage.
Keep the fuel filter covered with a clean
cloth when replacing.

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
38 Driving and Operating
{Warning
Engine exhaust contains Carbon
Monoxide (CO), which cannot be seen or
smelled. Exposure to CO can cause
unconsciousness or even death. Never
operate PTO in an enclosed area such as
a garage or building that has no fresh air
ventilation. See“Engine Exhaust” in the
owner’s manual.
Caution
If the key is in the ignition during
Remote PTO operation, the vehicle can be
shifted out of P (Park). Even though PTO
will be disengaged, depending on PTO
Upfitter application, personal injury or
property damage may result from vehicle
movement. Always remove the key from
the ignition before operating
Remote PTO.
Primary PTO Operating Modes
PTO modes of operation are:
.Preset
Stationary operation only: In-cab control
is standard, remote control is available.
.Variable
Stationary operation only: In-cab control
is standard, remote control is available.
.Mobile
In-cab control only.
.Operator Selectable In-Cab Mode (OSIM)
OSIM is for in-cab operation only.
OSIM is for vehicles that require both
stationary and mobile modes. OSIM is
available via the GM Service Tool only.
During the configuration of OSIM, two
modes must be paired. The options for
pairing are: stationary preset and mobile,
or stationary variable and mobile. During
activation of OSIM, the operator must
select one of the two modes within the
pre-configured pairing. If an OSIM mode is
not selected, PTO will not operate.
OSIM modes of operation are:
‐ Stationary
For stationary mode, the configuration
may be stationary preset or stationary
variable.
‐ Mobile
For mobile mode, the configuration is
variable only. Selection between OSIM pairings is not
available.
Remote modes are not available.
The factory default programming enables
in-cab control. For stationary modes, a GM
Service Tool can reprogram the system to
allow for remote control and disable the
in-cab control.
All PTO modes provide for engine rpm
control and PTO load relay control.
All PTO modes provide for safety interlocks
for PTO load disengagement.
Remote PTO modes provide for remote
engine starting and shutdown.
Stationary in-cab and Remote PTO modes
provide for engine shutdown due to critical
engine conditions, as well as a timed engine
shutdown feature.
Preset PTO
Preset Enable Conditions –In-Cab Operation
To enable PTO: 1. With the engine running, shift the vehicle into P (Park) and set the parking
brake. Do not press the brake pedal.
2. Confirm that cruise control is off.