2021 GMC TERRAIN lock

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
258 Vehicle Care
General Information
For service and parts needs, visit your
dealer. You will receive genuine GM parts
and GM-trained and supported service
people.
Genuine GM parts have one of these marks:
California Proposition 65 Warning
{Warning
Most motor vehicles, including this one,
as well as many of its service parts and
fluids, contain and/or emit chemicals
known to the State of California to cause(Continued)
Warning (Continued)
cancer and birth defects or other
reproductive harm. Engine exhaust, many
parts and systems, many fluids, and
some component wear by-products
contain and/or emit these chemicals. For
more information go to
www.P65Warnings.ca.gov/
passenger-vehicle.
See Battery - North America 0273 and
Jump Starting - North America 0316 and the
back cover.
California Perchlorate Materials
Requirements
Certain types of automotive applications,
such as airbag initiators, seat belt
pretensioners, and lithium batteries
contained in electronic keys, may contain
perchlorate materials. Perchlorate Material –
special handling may apply. See
www.dtsc.ca.gov/hazardouswaste/
perchlorate.
Accessories and Modifications
Adding non-dealer accessories or making
modifications to the vehicle can affect
vehicle performance and safety, including
such things as airbags, braking, stability,
ride and handling, emissions systems,
aerodynamics, durability, and electronic
systems like antilock brakes, traction control,
and stability control. These accessories or
modifications could even cause malfunction
or damage not covered by the vehicle
warranty.
Damage to suspension components caused
by modifying vehicle height outside of
factory settings will not be covered by the
vehicle warranty.
Damage to vehicle components resulting
from modifications or the installation or use
of non-GM certified parts, including control
module or software modifications, is not
covered under the terms of the vehicle
warranty and may affect remaining
warranty coverage for affected parts.
GM Accessories are designed to complement
and function with other systems on the
vehicle. See your dealer to accessorize the
vehicle using genuine GM Accessories
installed by a dealer technician.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
260 Vehicle Care
To open the hood:1. Pull the hood release lever with the
isymbol. It is on the lower left side
of the instrument panel.
2. Go to the front of the vehicle and locate the secondary release lever under the
front center of the hood. Push the
secondary hood release lever to the right
to release.
3. Lift the hood and release the hood proprod from its retainer in the front of the
engine compartment. Securely insert the
rod end into the slot marked with an
arrow, on the underside of the hood.
To close the hood: 1. Before closing the hood, be sure all filler caps are on properly, and all tools are
removed. 2. Lift the hood and remove the hood prop
rod from the underside of the hood.
Return the prop rod to its retainer. The
prop rod must click into place when
returning it to the retainer to prevent
hood damage.
3. Lower the hood 20 cm (8 in) above the vehicle and release it. Check to make
sure the hood is latched completely.
Repeat this process with additional force
if necessary.{Warning
Do not drive the vehicle if the hood is
not latched completely. The hood could
open fully, block your vision, and cause a
crash. You or others could be injured.
Always close the hood completely before
driving.

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
Vehicle Care 269
The coolant surge tank is located in the
engine compartment on the driver side of
the vehicle. SeeEngine Compartment
Overview 0261.
How to Add Coolant to the Coolant
Surge Tank
{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.
{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
Spilling coolant on hot engine parts can
burn you. Coolant contains ethylene
glycol and it will burn if the engine parts
are hot enough.
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.
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-quarter of a
turn. If you hear a hiss, wait for that to
stop. This will allow any pressure still
left to be vented out the discharge hose.
2. Keep turning the pressure cap slowly and remove it.
3. Fill the coolant surge tank with theproper mixture to the indicated
level mark.
4. With the coolant surge tank pressure cap off, start the engine and let it run until
you can feel the upper radiator hose
getting hot. Watch out for the engine
cooling fans.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
278 Vehicle Care
LED Lighting
This vehicle has several LED lamps. For
replacement of any LED lighting assembly,
contact your dealer.
Front Turn Signal Lamps
To replace one of these bulbs:1. Open the hood. See Hood0259.
2. Remove the bulb access cap from the top
of the headlamp assembly by turning it
counterclockwise.
3. Remove the bulb from the bulb socketby pinching the tabs on either side of
the bulb and pull straight out.
4. Install the new bulb in the bulb socket.
5. Install the bulb access cap onto the headlamp assembly by turning clockwise.
Taillamps
To replace one of these lamps:
1. Open the liftgate. See Liftgate017.
2. Remove the two screw caps and two
screws from the taillamp assembly.
3. Pull the taillamp assembly out of the vehicle body.
4. Disconnect the lamp wiring harness.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Vehicle Care 279
5. Turn the bulb socket counterclockwiseand pull it out.
6. Pull the bulb straight out of the socket.
7. Push the replacement bulb straight into the bulb socket.
8. Push the bulb socket in and turn it clockwise.
9. Reverse Steps 2–5 to reinstall the lamp assembly.
License Plate Lamp
Lamp Assembly
Bulb Assembly
1. Bulb Socket
2. Bulb
3. Lamp Assembly
To replace one of these bulbs:
1. Open the liftgate partway. See Liftgate
0 17.
2. Push the lamp assembly outboard to remove.
3. Pull the lamp assembly down to remove it from the liftgate.
4. Turn the bulb socket (1) counterclockwise to remove it from the lamp assembly (3).
5. Pull the bulb (2) straight out of the bulb socket (1).
6. Push the replacement bulb straight into the bulb socket and turn the bulb socket
clockwise to install it into the lamp
assembly.
7. Push the lamp assembly into the liftgate engaging the clip side first.
8. Push on the lamp side opposite the clip until the lamp assembly snaps into place.