2021 GMC TERRAIN tow

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
254 Driving and Operating
The trailer tongue weight (1) should be 10–
15% of the loaded trailer weight (2). Some
specific trailer types, such as boat trailers,
fall outside of this range. Always refer to
the trailer owner’s manual for the
recommended trailer tongue weight for each
trailer. Never exceed the maximum loads for
your vehicle, hitch and trailer.
After loading the trailer, separately weigh
the trailer and then the trailer tongue and
calculate the trailer load balance percentage
to see if the weights and distribution are
appropriate for your vehicle. If the trailer
weight is too high, it may be possible to
trasfer some of the cargo into your vehicle.
If the trailer tongue weight is too high or
too low, it may be possible to rearrange
some of the cargo inside of the trailer.
Do not exceed the maximum allowable
tongue weight for your vehicle. Use the
shortest hitch extension available to position
the hitch ball closer to your vehicle. This will
help reduce the effect of the trailer tongue
weight on the trailer hitch and the rear axle.
If a cargo carrier is used in the trailer hitch
receiver, choose a carrier that positions the
load as close to the vehicle as possible.
Make sure the total weight, including thecarrier, is no more than half of the
maximum allowable tongue weight for the
vehicle or 227 kg (500 lb), whichever is less.
Ask your dealer for trailering information or
assistance.
Towing Equipment
Hitches
Always use the correct hitch equipment for
your vehicle. Crosswinds, large trucks going
by, and rough roads can affect the trailer
and the hitch.
Proper hitch equipment for your vehicle
helps maintain control of the vehicle-trailer
combination. Many trailers can be towed
using a weight-carrying hitch which has a
coupler latched to the hitch ball, or a tow
eye latched to a pintle hook. Other trailers
may require a weight-distributing hitch that
uses spring bars to distribute the trailer
tongue weight between your vehicle and
trailer axles. See
“Maximum Trailer Tongue
Weight” underTrailer Towing 0251 for
weight limits with various hitch types.
Never attach rental hitches or other
bumper-type hitches. Only use
frame-mounted hitches that do not attach to
the bumper.
Hitch Cover
To remove the hitch cover:
1. Remove two fasteners (2).
2. Pull the bottom edge of the cover rearward.
3. Disengage the cover at the upper attachments (1) and remove.
Consider using mechanical sway controls
with any trailer. Ask a trailering professional
about sway controls or refer to the trailer
manufacturer's recommendations and
instructions.
Tires
.Do not tow a trailer while using a
compact spare tire on the vehicle.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 255
.Tires must be properly inflated to support
loads while towing a trailer. SeeTires
0 287 for instructions on proper tire
inflation.
Safety Chains
Always attach chains between the vehicle
and the trailer, and attach the chains to the
holes on the trailer hitch platform.
Instructions about safety chains may be
provided by the hitch manufacturer or by
the trailer manufacturer.
Cross the safety chains under the tongue of
the trailer to help prevent the tongue from
contacting the road if it becomes separated
from the hitch. Always leave just enough
slack so the combination can turn. Never
allow safety chains to drag on the ground.
Trailer Brakes
Loaded trailers over 450 kg (1,000 lb) must
be equipped with brake systems and with
brakes for each axle. Trailer braking
equipment conforming to Canadian
Standards Association (CSA) requirement
CAN3-D313, or its equivalent, is
recommended. State or local regulations may require
trailers to have their own braking system if
the loaded weight of the trailer exceeds
certain minimums that can vary from state
to state. Read and follow the instructions for
the trailer brakes so they are installed,
adjusted, and maintained properly. Never
attempt to tap into your vehicle's hydraulic
brake system. If you do, both the vehicle
anti-lock brakes and the trailer brakes may
not function, which could result in a crash.
Trailer Lamps
Always check all trailer lamps are working at
the beginning of each trip, and periodically
on longer trips.
Turn Signals When Towing a Trailer
When properly connected, the trailer turn
signals will illuminate to indicate the vehicle
is turning, changing lanes, or stopping.
When towing a trailer, the arrows on the
instrument cluster will illuminate even if the
trailer is not properly connected or the bulbs
are burned out.
Trailer Tires
Special Trailer (ST) tires differ from vehicle
tires. Trailer tires are designed with stiff
sidewalls to help prevent sway and tosupport heavy loads. These features can
make it difficult to determine if the trailer
tire pressures are low only based on a visual
inspection.
Always check all trailer tire pressures before
each trip when the tires are cool. Low trailer
tire pressure is a leading cause of trailer tire
blow-outs.
Trailer tires deteriorate over time. The trailer
tire sidewall will show the week and year
the tire was manufactured. Many trailer tire
manufacturers recommend replacing tires
more than six years old.
Overloading is another leading cause of
trailer tire blow-outs. Never load your trailer
with more weight than the tires are
designed to support. The load rating is
located on the trailer tire sidewall.
Always know the maximum speed rating for
the trailer tires before driving. This may be
significantly lower than the vehicle tire
speed rating. The speed rating may be on
the trailer tire sidewall. If the speed rating is
not shown, the default trailer tire speed
rating is 105 km/h (65 mph).

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Vehicle Care 257
Vehicle Care
General Information
General Information . . . . . . . . . . . . . . . . . . . 258
California Proposition 65 Warning . . . . . 258
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . . . . . . 258
Accessories and Modifications . . . . . . . . . 258
Vehicle Checks
Doing Your Own Service Work . . . . . . . . 259
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
Engine Compartment Overview . . . . . . . . 261
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
Engine Oil Life System . . . . . . . . . . . . . . . . 264
Automatic Transmission Fluid . . . . . . . . . 265
Engine Air Filter Life System . . . . . . . . . . 265
Engine Air Cleaner/Filter . . . . . . . . . . . . . . 265
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 267
Engine Overheating . . . . . . . . . . . . . . . . . . . 270
Washer Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Battery - North America . . . . . . . . . . . . . . . 273
All-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . . . 274
Starter Switch Check . . . . . . . . . . . . . . . . . . 274
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
Wiper Blade Replacement . . . . . . . . . . . . . 275
Windshield Replacement . . . . . . . . . . . . . . 276 Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . 277
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . 277
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . 277
High Intensity Discharge (HID)
Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Front Turn Signal Lamps . . . . . . . . . . . . . . . 278
Taillamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
License Plate Lamp . . . . . . . . . . . . . . . . . . . . 279
Electrical System
Electrical System Overload . . . . . . . . . . . . 280
Fuses and Circuit Breakers . . . . . . . . . . . . 280
Engine Compartment Fuse Block . . . . . . . 281
Instrument Panel Fuse Block . . . . . . . . . . 284
Rear Compartment Fuse Block . . . . . . . . . 285
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . 287
Winter Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Summer Tires . . . . . . . . . . . . . . . . . . . . . . . . . 288
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . 288
Tire Designations . . . . . . . . . . . . . . . . . . . . . 290
Tire Terminology and Definitions . . . . . . 291
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Tire Pressure Monitor System . . . . . . . . . 294 Tire Pressure Monitor Operation . . . . . . 295
Tire Inspection . . . . . . . . . . . . . . . . . . . . . . . . 298
Tire Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . 298
When It Is Time for New Tires . . . . . . . . 299
Buying New Tires . . . . . . . . . . . . . . . . . . . . . 300
Different Size Tires and Wheels . . . . . . . 301
Uniform Tire Quality Grading . . . . . . . . . . 301
Wheel Alignment and Tire Balance . . . . 302
Wheel Replacement . . . . . . . . . . . . . . . . . . . 302
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . 303
Tire Sealant and Compressor Kit . . . . . . 305
Storing the Tire Sealant and
Compressor Kit . . . . . . . . . . . . . . . . . . . . . . 310
Tire Changing . . . . . . . . . . . . . . . . . . . . . . . . . 310
Compact Spare Tire . . . . . . . . . . . . . . . . . . . . 315
Jump Starting
Jump Starting - North America . . . . . . . . 316
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . . . . . . . . . . 318
Recreational Vehicle Towing . . . . . . . . . . . 320
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Vehicle Care 259
Also, seeAdding Equipment to the
Airbag-Equipped Vehicle 056.
Vehicle Checks
Doing Your Own Service Work
{Warning
It can be dangerous to work on your
vehicle if you do not have the proper
knowledge, service manual, tools,
or parts. Always follow owner’s manual
procedures and consult the service
manual for your vehicle before doing any
service work.
If doing some of your own service work, use
the proper service manual. It tells you much
more about how to service the vehicle than
this manual can. To order the proper service
manual, see Publication Ordering
Information 0353. This vehicle has an airbag system. Before
attempting to do your own service work,
see
Servicing the Airbag-Equipped Vehicle
0 55.
If equipped with remote vehicle start, open
the hood before performing any service
work to prevent remote starting the vehicle
accidentally. See Remote Vehicle Start 013.
Keep a record with all parts receipts and list
the mileage and the date of any service
work performed. See Maintenance Records
0 341.
Caution
Even small amounts of contamination can
cause damage to vehicle systems. Do not
allow contaminants to contact the fluids,
reservoir caps, or dipsticks.
Hood
{Warning
For vehicles with auto engine stop/start,
turn the vehicle off before opening the
hood. If the vehicle is on, the engine will
start when the hood is opened. You or
others could be injured.
{Warning
Components under the hood can get hot
from running the engine. To help avoid
the risk of burning unprotected skin,
never touch these components until they
have cooled, and always use a glove or
towel to avoid direct skin contact.
Clear any snow from the hood before
opening.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
262 Vehicle Care
1.Engine Air Cleaner/Filter 0265.
2. Engine Oil Fill Cap. See Engine Oil0262.
3. Engine Oil Dipstick. See Engine Oil0262.
4. Engine Cooling Fan. See Cooling System
0 267.
5. Brake Fluid Reservoir. See Brake Fluid
0 272.
6. Engine Compartment Fuse Block 0281.
7. Remote Positive (+) Terminal (Under Cover). See Jump Starting - North
America 0316.
8. Engine Coolant Surge Tank and Pressure Cap. See Cooling System 0267.
9. Battery - North America 0273.
10. Remote Negative (−) Terminal. See Jump
Starting - North America 0316.
11. Windshield Washer Fluid Reservoir. See Washer Fluid 0271.
Engine Oil
To ensure proper engine performance and
long life, careful attention must be paid to
engine oil. Following these simple, but
important steps will help protect your
investment:
.Use engine oil approved to the proper
specification and of the proper viscosity
grade. See “Selecting the Right Engine
Oil” in this section.
.Check the engine oil level regularly and
maintain the proper oil level. See
“Checking Engine Oil” and“When to Add
Engine Oil” in this section.
.Change the engine oil at the appropriate
time. SeeEngine Oil Life System 0264.
.Always dispose of engine oil properly. See
“What to Do with Used Oil” in this
section.
Checking Engine Oil
Check the engine oil level regularly, every
650 km (400 mi), especially prior to a long
trip. The engine oil dipstick handle is a loop.
See Engine Compartment Overview 0261 for
the location.
{Warning
The engine oil dipstick handle may be
hot; it could burn you. Use a towel or
glove to touch the dipstick handle. If a low oil Driver Information Center (DIC)
message displays, check the oil level. If the
oil is not low and the low oil message
remains on, take the vehicle to your dealer
for service.
Follow these guidelines:
.To get an accurate reading, park the
vehicle on level ground. Check the engine
oil level after the engine has been off for
at least two hours. Checking the engine
oil level on steep grades or too soon after
engine shutoff can result in incorrect
readings. Accuracy improves when
checking a cold engine prior to starting.
Remove the dipstick and check the level.
.If unable to wait two hours, the engine
must be off for at least 15 minutes if the
engine is warm, or at least 30 minutes if
the engine is not warm. Pull out the
dipstick, wipe it with a clean paper towel
or cloth, then push it back in all the way.
Remove it again, keeping the tip down,
and check the level.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
270 Vehicle Care
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 indicated
level mark.
5. Replace the pressure 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.
If the coolant still is not at the proper
level when the system cools down again,
see your dealer.
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 and overheat messages in the Driver
Information Center (DIC) to warn of engine
overheating. See Engine Coolant
Temperature Gauge 091. The decision may be made not to lift the
hood when the engine coolant temperature
gauge is in the overheat zone or an engine
overheat DIC message displays, but instead
to get service help right away. See
Roadside
Assistance Program 0349.
If the decision to lift the hood is made,
make sure the vehicle is parked on a level
surface. Then check to see if the engine
cooling fan(s) are running. If the engine is
overheating, the fan(s) should be running.
If they are not, do not continue to run the
engine, and have the vehicle serviced.
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 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.
If No Steam Is Coming from the Engine
Compartment
If the engine coolant temperature gauge is
in the overheat zone or an engine overheat
DIC message is displayed but no steam can
be seen or heard, 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

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Vehicle Care 275
Wiper Blade Replacement
Windshield wiper blades should be replaced
periodically. SeeMaintenance Schedule
0 331.
Replacement blades come in different types
and are removed in different ways. For
proper type and length, see Maintenance
Replacement Parts 0340.
Caution
Allowing the wiper arm to touch the
windshield when no wiper blade is
installed could damage the windshield.
Any damage that occurs would not be
covered by the vehicle warranty. Do not
allow the wiper arm to touch the
windshield.
Front Wiper Blade Replacement
To replace the wiper blade:
1. Pull the wiper assembly away from the windshield.
2. Lift up on the latch in the middle of the
wiper blade where the wiper arm
attaches.
3. With the latch open, pull the wiper blade down toward the windshield far enough
to release it from the J-hooked end of
the wiper arm.
4. Remove the wiper blade.
5. Reverse Steps 1–3 for wiper blade replacement.
Rear Wiper Blade Replacement
The rear wiper blade and wiper arm have a
cover for protection.
To remove the cover:
1. Slide a plastic tool under the cover andpush upward to unsnap.
2. Slide the cover toward the wiper blade tip to unhook it from the blade
assembly.
3. Remove the cover.
4. After wiper blade replacement, ensure that the cover hook slides into the slot
in the blade assembly.
5. Snap the cover down to secure.
To replace the wiper blade: 1. Lift the wiper arm away from the windshield.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Vehicle Care 299
Check that all wheel nuts are properly
tightened. See“Wheel Nut Torque”
under Capacities and Specifications
0 343, and “Removing the Flat Tire and
Installing the Spare Tire” underTire
Changing 0310.
{Warning
Rust or dirt on a wheel, or on the
parts to which it is fastened, can
cause wheel nuts to become loose
over time. The wheel could come off
and cause a crash. When changing a
wheel, remove any rust or dirt from
places where the wheel attaches to
the vehicle. In an emergency, a cloth
or paper towel can be used; however,
use a scraper or wire brush later to
remove all rust or dirt.
Lightly coat the inner diameter of the
wheel hub opening with wheel bearing
grease after a wheel change or tire
rotation to prevent corrosion or rust
buildup.
{Warning
Do not apply grease to the wheel
mounting surface, wheel conical
seats, or the wheel nuts or bolts.
Grease applied to these areas could
cause a wheel to become loose or
come off, resulting in a crash.
When It Is Time for New Tires
Factors, such as maintenance, temperatures,
driving speeds, vehicle loading, and road
conditions affect the wear rate of the tires.
Treadwear indicators are one way to tell
when it is time for new tires. Treadwear
indicators appear when the tires have only 1.6 mm (1/16 in) or less of tread remaining.
See
Tire Inspection 0298 and
Tire Rotation 0298 for additional
information.
The rubber in tires ages over time. This also
applies to the spare tire, if the vehicle has
one, even if it is never used. Multiple factors
including temperatures, loading conditions,
and inflation pressure maintenance affect
how fast aging takes place. GM recommends
that tires, including the spare if equipped,
be replaced after six years, regardless of
tread wear. To identify the age of a tire, use
the tire manufacture date, which is the last
four digits of the DOT Tire Identification
Number (TIN) molded into one side of the
tire sidewall. The last four digits of the TIN
indicate the tire manufactured date. The
first two digits represent the week and the
last two digits, the year. For example, the
third week of the year 2020 would have a
4-digit DOT date of 0320. Week 01 is the
first full week (Sunday through Saturday) of
each year.
Vehicle Storage
Tires age when stored normally mounted on
a parked vehicle. Park a vehicle that will be
stored for at least a month in a cool, dry,
clean area away from direct sunlight to slow