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
60 Vehicle Care
Caution
If the air cleaner/filter is off, dirt can
easily get into the engine, which could
damage it. Always have the air cleaner/
filter in place when driving.
Cooling System
The cooling system allows the engine to
maintain the correct working temperature.
2.8L 4-Cylinder Engine Pickup Models
See“Cooling System” in the owner’s
manual.
2.8L 4-Cylinder Engine Van Models
1. Coolant Surge Tank
2. Coolant Surge Tank Pressure Cap
3. Engine Cooling Fan (Out of View)
{Warning
An underhood electric fan can start up
even when the engine is not running and
can cause injury. Keep hands, clothing,
and tools away from any underhood
electric fan.
{Warning
Do not touch heater or radiator hoses,
or other engine parts. They can be very
hot and can burn you. Do not run the
engine if there is a leak; all coolant could
leak out. That could cause an engine fire
and can burn you. Fix any leak before
driving the vehicle.
Engine Coolant
The cooling system in the vehicle is
filled with DEX-COOL engine coolant
mixture. See Recommended Fluids and
Lubricants 078 and
Maintenance Schedule 073 or
Maintenance Schedule 077. The following explains the cooling system
and how to add coolant when it is low.
If there is a problem with engine
overheating, see
Engine Overheating 062.
A 50/50 mixture of clean, drinkable water
and DEX-COOL coolant will:
.Give freezing protection down to −37 °C
(−34 °F).
.Give boiling protection up to 129 °C
(265 °F).
.Protect against rust and corrosion.
.Help keep the proper engine temperature.
.Let the warning lights and gauges work
as they should.
What to Use
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain water or
the wrong mixture, the engine could get
too hot but there would not be an
overheat warning. The engine could catch
fire and you or others could be burned.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Vehicle Care 61
Use a 50/50 mixture of clean, drinkable
water and DEX-COOL coolant which will not
damage aluminum parts. If using this
mixture, nothing else needs to be added.
If coolant has to be added more than four
times a year, have your dealer check the
vehicle cooling system.
Caution
Do not use anything other than a mix of
DEX-COOL coolant that meets GM
Standard GMW3420 and clean, drinkable
water. Anything else can cause damage
to the engine cooling system and the
vehicle, which would not be covered by
the vehicle warranty.
Never dispose of engine coolant by putting
it in the trash, or by pouring it on the
ground or into sewers, streams, or bodies of
water. Have the coolant changed by an
authorized service center, familiar with legal
requirements regarding used coolant
disposal. This will help protect the
environment and your health.
Checking Coolant (2.8L 4-Cylinder Engine
Pickup Models)
See “Engine Coolant” in the owner’s manual. Checking Coolant (2.8L 4-Cylinder Engine Van
Models)
The coolant surge tank is near the center of
the engine compartment. See
Engine
Compartment Overview 053 for location.
The vehicle must be on a level surface.
When the engine is cold, the coolant level
should be at the indicated mark.
Adding Coolant (2.8L 4-Cylinder Engine Pickup
Models)
See “Engine Coolant” in the owner’s manual. Adding Coolant (2.8L 4-Cylinder Engine Van
Models)
Caution
If coolant is changed or added, always
add enough to fill the system completely
or engine damage may occur.
If more coolant is needed, add the proper
DEX-COOL coolant mixture at the surge tank,
but be careful not to spill it.
{Warning
Spilling coolant on hot engine parts can
burn you. Coolant contains ethylene
glycol and it will burn if the engine parts
are hot enough.
{Warning
Steam and scalding liquids from a hot
cooling system are under pressure.
Turning the pressure cap, even a little,
can cause them to come out at high
speed and you could be burned. Never
turn the cap when the cooling system, (Continued)

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
62 Vehicle Care
Warning (Continued)
including the pressure cap, is hot. Wait
for the cooling system and pressure cap
to cool.
If no coolant is visible in the surge tank, add
coolant as follows:
2.8L 4-Cylinder Van Pressure Cap
1. Remove the coolant surge tank pressure cap when the cooling system, including
the coolant surge tank pressure cap and
upper radiator hose, is no longer hot.
Turn the pressure cap slowly
counterclockwise about one full turn. If a
hiss is heard, wait for that to stop.
A hiss means there is still some
pressure left.
2. Keep turning the pressure cap slowly, and remove it. 3. Slowly fill the coolant surge tank. Do not
let the coolant level go above the
indicated mark in the tank until after the
engine comes to operating temperature
in Step 4.
4. With the coolant surge tank pressure cap off, start the engine and let it run until
the engine coolant temperature gauge
indicates approximately 90 °C (195 °F).
By this time, the coolant level inside the
coolant surge tank may be lower. If the
level is lower, slowly add more of the
proper mixture to the coolant surge tank
until it reaches the indicated mark.
5. Re-install the pressure cap. Be sure the pressure cap is hand-tight
and fully seated.
6. Verify coolant level after the engine is shut off and the coolant is cold.
If necessary, repeat Steps 1–6.
If the coolant level is still low after having
followed these steps twice, have the coolant
system checked by a certified technician at
the dealer for a possible leak.
Caution
If the pressure cap is not tightly installed,
coolant loss and engine damage may
occur. Be sure the cap is properly and
tightly secured.
Engine Overheating
There is an engine coolant temperature
gauge on the instrument cluster. See the
owner’s manual.
If Steam Is Coming from the Engine
Compartment
{Warning
Steam and scalding liquids from a hot
cooling system are under pressure.
Turning the pressure cap, even a little,
can cause them to come out at high
speed and you could be burned. Never
turn the cap when the cooling system,
including the pressure cap, is hot. Wait
for the cooling system and pressure cap
to cool.

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
64 Vehicle Care
Electrical System
Engine Compartment Fuse Block
For additional fuse and electrical
information, see“Electrical System” in the
owner’s manual.
The engine compartment fuse block is in the
engine compartment, on the driver side of
the vehicle. See Engine Compartment
Overview 053
Lift the cover to access the fuse block.
Caution
Spilling liquid on any electrical
component on the vehicle may damage
it. Always keep the covers on any
electrical component. A fuse puller is available inside this fuse
block.
{Danger
Fuses and circuit breakers are marked
with their ampere rating. Do not exceed
the specified amperage rating when
replacing fuses and circuit breakers. Use
of an oversized fuse or circuit breaker can
result in a vehicle fire. You and others
could be seriously injured or killed.

Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Vehicle Care 65
4-Cylinder Pickup

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
68 Vehicle Care
4-Cylinder Van

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