2021 CHEVROLET COLORADO engine overheat

Chevrolet Colorado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14430421) - 2021 - CRC - 2/10/20
Driving and Operating 195
Caution (Continued)
transmission. The repair will not be
covered by the vehicle warranty. If the
vehicle is stuck, do not spin the tires.
When stopping on a hill, use the brakes
to hold the vehicle in place.
Low Traction Mode
If equipped, Low Traction Mode assists in
vehicle acceleration when road conditions
are slippery, such as with ice or snow. While
the vehicle is at a stop, select L2 using
Range Selection Mode. This will limit torque
to the wheels and help to prevent the tires
from spinning.
Tow/Haul Mode
If equipped, Tow/Haul Mode adjusts the
transmission shift pattern to reduce shift
cycling. While towing heavy loads, this
mode provides increased performance and
vehicle control.
Turn the Tow/Haul Mode on and off by
pressing the button on the center stack.
When the Tow/Haul Mode is enabled, a
light on the instrument cluster will come on.
SeeTow/Haul Mode Light 089 and
Hill and Mountain Roads 0177.
Also see “Tow/Haul Mode” underTowing
Equipment 0228.
If the vehicle has a diesel engine, the Tow/
Haul button activates the exhaust brake
system simultaneously. See “Exhaust Brake”
in the Duramax diesel supplement.
Drive Systems
Four-Wheel Drive
If equipped, four-wheel drive engages the
front axle for extra traction.
Caution
Do not drive on clean, dry pavement in
4
m, or 4nfor an extended period of
time. These conditions may cause:
.Overheating.
.Oil leakage.
.Damage to internal and external
components of the front axle.
.Premature wear on the vehicle’s
powertrain.
Driving on clean, dry pavement in 4
mor
4
nmay:
.Cause a vibration to be felt in the
steering system.
.Cause tires to wear faster.
.Cause additional driveline noise.
{Warning
If equipped with four-wheel drive, the
vehicle will be free to roll if the transfer
case is in N (Neutral), even when the shift
lever is in P (Park). You or someone else
could be seriously injured. Be sure the
transfer case is in a drive gear —2
m, 4m,
(Continued)

Chevrolet Colorado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14430421) - 2021 - CRC - 2/10/20
Driving and Operating 221
Warning (Continued)
.Fully open the air outlets on or under
the instrument panel.
.Adjust the climate control system to a
setting that brings in only outside air.
See“Climate Control Systems” in the
Index.
For more information about carbon
monoxide, see Engine Exhaust 0190.
Towing a trailer requires experience. The
combination of the vehicle and trailer is
longer and not as responsive as the vehicle
itself. Get used to the handling and braking
of the combination by driving on a level
road surface before driving on public roads.
The trailer structure, the tires, and the
brakes must all be rated to carry the
intended cargo. Inadequate trailer
equipment can cause the combination to
operate in an unexpected or unsafe manner.
Before driving, inspect all trailer hitch parts
and attachments, safety chains, electrical
connectors, lamps, tires, and mirrors. See
Towing Equipment 0228. If the trailer has
electric brakes, start the combination
moving and then manually apply the trailer
brake controller to check the trailer brakes work. During the trip, occasionally check
that the cargo and trailer are secure and
that the lamps and any trailer brakes are
working.Towing with a Stability Control System
When towing, the stability control system
might be heard. The system reacts to
vehicle movement caused by the trailer,
which mainly occurs during cornering. This is
normal when towing heavier trailers.
Following Distance
Stay at least twice as far behind the vehicle
ahead as you would when driving without a
trailer. This can help to avoid heavy braking
and sudden turns.
Passing
More passing distance is needed when
towing a trailer. The combination of the
vehicle and trailer will not accelerate as
quickly and is much longer than the vehicle
alone. It is necessary to go much farther
beyond the passed vehicle before returning
to the lane. Pass on level roadways. Avoid
passing on hills if possible.
Backing Up
Hold the bottom of the steering wheel with
one hand. To move the trailer to the left,
move that hand to the left. To move the
trailer to the right, move that hand to the
right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Caution
Turn more slowly and make wider arcs
when towing a trailer to prevent damage
to your vehicle. Making very sharp turns
could cause the trailer to contact the
vehicle.
Make wider turns than normal when towing,
so trailer will not go over soft shoulders,
over curbs, or strike road signs, trees,
or other objects. Always signal turns well in
advance. Do not steer or brake suddenly.
Driving on Grades
Reduce speed and shift to a lower gear
before starting down a long or steep
downhill grade. If the transmission is not
shifted down, the brakes may overheat and
result in reduced braking efficiency.

Chevrolet Colorado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14430421) - 2021 - CRC - 2/10/20
222 Driving and Operating
The vehicle can tow in D (Drive). Shift the
transmission to a lower gear if the
transmission shifts too often under heavy
loads and/or hilly conditions.
When towing at higher altitudes, engine
coolant will boil at a lower temperature
than at lower altitudes. If the engine is
turned off immediately after towing at high
altitude on steep uphill grades, the vehicle
could show signs similar to engine
overheating. To avoid this, let the engine
run, preferably on level ground, with the
transmission in P (Park) for a few minutes
before turning the engine off. If the
overheat warning comes on, seeEngine
Overheating 0250.
Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and trailer on a
level surface when possible. When parking your vehicle and your trailer
on a hill:
1. Press the brake pedal, but do not shift into P (Park) yet. Turn the wheels into
the curb if facing downhill or into traffic
if facing uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, gradually release the brake pedal to
allow the chocks to absorb the load of
the trailer.
4. Reapply the brake pedal. Then apply the parking brake and shift into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
.Start the engine.
.Shift into a gear.
.Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Launching and Retrieving a Boat
Backing the Trailer into the Water
{Warning
.Have all passengers get out of the
vehicle before backing onto the sloped
part of the ramp. Lower the driver and
passenger side windows before
backing onto the ramp. This will
provide a means of escape in the
unlikely event the vehicle slides into
the water.
.If the boat launch surface is slippery,
have the driver remain in the vehicle
with the brake pedal applied while the
boat is being launched. The boat
launch can be especially slippery at
low tide when part of the ramp was
previously submerged at high tide. Do
not back onto the ramp to launch the
boat if you are not sure the vehicle
can maintain traction.
.Do not move the vehicle if someone is
in the path of the trailer. Some parts
of the trailer might be underwater and
not visible to people who are assisting
in launching the boat.

Chevrolet Colorado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14430421) - 2021 - CRC - 2/10/20
Driving and Operating 223
Disconnect the wiring to the trailer before
backing the trailer into the water to prevent
damage to the electrical circuits on the
trailer. Reconnect the wiring to the trailer
after removing the trailer from the water.
If the trailer has electric brakes that can
function when the trailer is submerged, it
might help to leave the electrical trailer
connector attached to maintain trailer brake
functionality while on the boat ramp.
To back the trailer into the water:1. If equipped, place the vehicle in four-wheel-drive high.
2. Slowly back down the boat ramp until the boat is floating, but no further than
necessary.
3. Press and hold the brake pedal, but do not shift into P (Park) yet.
4. Have someone place chocks under the front wheels of the vehicle.
5. Gradually release the brake pedal to allow the chocks to absorb the load of
the trailer. 6. Reapply the brake pedal. Then apply the
parking brake and shift into P (Park).
7. Release the brake pedal.
Pulling the Trailer from the Water
To pull the trailer of the water: 1. Press and hold the brake pedals.
2. Start the engine and shift into gear.
3. Release the parking brake.
4. Let up on the brake pedal.
5. Drive slowly until the tires are clear of the chocks.
6. Stop and have someone pick up and store the chocks.
7. Slowly pull the trailer from the water.
8. Once the vehicle and trailer have been driven from the sloped part of the boat
ramp, the vehicle can be shifted from
four-wheel-drive high. Shift into the drive
mode that is appropriate for the road
conditions.Caution
If the vehicle tires begin to spin and the
vehicle begins to slide toward the water,
remove your foot from the accelerator
pedal and apply the brake pedal. Seek
help to have the vehicle towed up
the ramp.
Maintenance when Trailer Towing
The vehicle needs service more often when
used to tow trailers. See Maintenance
Schedule 0312. It is especially important to
check the automatic transmission fluid,
engine oil, axle lubricant, belts, cooling
system, and brake system before and during
each trip.
Check periodically to see that all nuts and
bolts on the trailer hitch are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily
overheat during severe operating conditions.
See Engine Overheating 0250.

Chevrolet Colorado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14430421) - 2021 - CRC - 2/10/20
236 Vehicle Care
Vehicle Care
General Information
General Information . . . . . . . . . . . . . . . . . . . 237
California Proposition 65 Warning . . . . . 237
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . . . . . . 237
Accessories and Modifications . . . . . . . . . 237
Vehicle Checks
Doing Your Own Service Work . . . . . . . . 238
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
Engine Compartment Overview . . . . . . . 240
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Engine Oil Life System . . . . . . . . . . . . . . . . 245
Automatic Transmission Fluid . . . . . . . . . 246
Engine Air Cleaner/Filter . . . . . . . . . . . . . . 246
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 247
Engine Overheating . . . . . . . . . . . . . . . . . . . 250
Engine Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
Washer Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 252
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
Battery - North America . . . . . . . . . . . . . . . 254
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 254
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
Starter Switch Check . . . . . . . . . . . . . . . . . . 256
Automatic Transmission Shift Lock Control Function Check . . . . . . . . . . . . . . 256 Ignition Transmission Lock Check . . . . . . 256
Park Brake and P (Park) Mechanism
Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
Wiper Blade Replacement . . . . . . . . . . . . . 257
Windshield Replacement . . . . . . . . . . . . . . . 257
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . 258
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . 258
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . 259
Headlamps, Front Turn Signal, Sidemarker, and Parking Lamps . . . . . . 259
Taillamps, Stoplamps, and Back-Up Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
Electrical System
Electrical System Overload . . . . . . . . . . . . . 261
Fuses and Circuit Breakers . . . . . . . . . . . . . 261
Engine Compartment Fuse Block . . . . . . 262
Instrument Panel Fuse Block . . . . . . . . . . 266
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . 268
Winter Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
All-Terrain Tires . . . . . . . . . . . . . . . . . . . . . . . 269
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . 269
Tire Designations . . . . . . . . . . . . . . . . . . . . . . 271
Tire Terminology and Definitions . . . . . . 272 Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 274
Tire Pressure Monitor System . . . . . . . . . 275
Tire Pressure Monitor Operation . . . . . . . 275
Tire Inspection . . . . . . . . . . . . . . . . . . . . . . . . 278
Tire Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . 278
When It Is Time for New Tires . . . . . . . . 279
Buying New Tires . . . . . . . . . . . . . . . . . . . . . 280
Different Size Tires and Wheels . . . . . . . . 281
Uniform Tire Quality Grading . . . . . . . . . . 281
Wheel Alignment and Tire Balance . . . . 283
Wheel Replacement . . . . . . . . . . . . . . . . . . . 283
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . 284
Tire Changing . . . . . . . . . . . . . . . . . . . . . . . . . 285
Compact Spare Tire . . . . . . . . . . . . . . . . . . . 294
Full-Size Spare Tire . . . . . . . . . . . . . . . . . . . . 295
Jump Starting
Jump Starting - North America . . . . . . . . 296
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . . . . . . . . . . 298
Recreational Vehicle Towing . . . . . . . . . . . 299
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . 303
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309

Chevrolet Colorado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14430421) - 2021 - CRC - 2/10/20
248 Vehicle Care
3.6L V6 Engine
1. Coolant Surge Tank and Pressure Cap
2. 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 Lubricants0321
and
Maintenance Schedule 0312.
The following explains the cooling system
and how to check and add coolant when it
is low. If there is a problem with engine
overheating, see Engine Overheating 0250.
What to Use
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain water or
(Continued)
Warning (Continued)
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.
Use a 50/50 mixture of clean, drinkable
water and DEX-COOL coolant. This mixture:
.Gives freezing protection down to −37 °C
(−34 °F) outside temperature.
.Gives boiling protection up to 129 °C
(265 °F) engine temperature.
.Protects against rust and corrosion.
.Will not damage aluminum parts.
.Helps keep the proper engine
temperature.
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.

Chevrolet Colorado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14430421) - 2021 - CRC - 2/10/20
Vehicle Care 249
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
The vehicle must be on a level surface when
checking the coolant level.
Check to see if coolant is visible in the
coolant surge tank. If the coolant inside the
coolant surge tank is boiling, do not do
anything else until it cools down.If coolant is visible but the coolant level is
not at or above the mark pointed to, add a
50/50 mixture of clean, drinkable water and
DEX-COOL coolant.
Be sure the cooling system is cool before
this is done.
If no coolant is visible in the coolant surge
tank, add coolant as follows:
How to Add Coolant to the Coolant
Surge Tank
{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
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.
{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.
Caution
Failure to follow the specific coolant fill
procedure could cause the engine to
overheat and could cause system
damage. If coolant is not visible in the
surge tank, contact your dealer.
The coolant surge tank pressure cap can be
removed when the cooling system, including
the surge tank pressure cap and upper
radiator hose, is no longer hot.

Chevrolet Colorado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14430421) - 2021 - CRC - 2/10/20
250 Vehicle Care
1. Turn the pressure cap slowlycounterclockwise. If a hiss is heard, wait
for that to stop. A hiss means there is
still some pressure left.
2. Keep turning the cap and remove it.
3. Fill the coolant surge tank with the proper mixture to the mark pointed to
on the front of the coolant surge tank. 4. With the coolant surge tank cap off,
start the engine and let it run until the
upper radiator hose starts getting hot.
Watch out for the engine cooling fan. By
this time, the coolant level inside the
coolant surge tank may be lower. If the
level is lower, add more of the proper
mixture to the coolant surge tank until
the level reaches the mark pointed to on
the front of the coolant surge tank.
5. Replace the cap tightly.
6. Verify coolant level after the engine is shut off and the coolant is cold.
If necessary, repeat coolant fill procedure
Steps 1–6.
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
The vehicle has an engine coolant
temperature gauge on the instrument
cluster to warn of engine overheating. See
Engine Coolant Temperature Gauge 084.
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 the decision is made not to lift the hood
when this warning appears, get service help
right away.
If the decision is made to lift the hood,
make sure the vehicle is parked on a level
surface.
Then check to see if the engine cooling fan
is running. If the engine is overheating, the
fan should be running. If it is not, do not
continue to run the engine and have the
vehicle serviced.
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 (Continued)