air condition GMC TERRAIN 2021 Owner's Guide

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 251
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.
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 0270.
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.
Maintenance When Trailer Towing
The vehicle needs service more often when
used to tow trailers. See Maintenance
Schedule 0331. 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 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 0270.
Trailer Towing
Caution
Towing a trailer improperly can damage
the vehicle and result in costly repairs
not covered by the vehicle warranty. To
(Continued)

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Vehicle Care 265
4. If the display changes to 100%, thesystem is reset.
If the CHANGE ENGINE OIL SOON message
comes back on when the vehicle is started,
the engine oil life system has not reset.
Repeat the procedure.
Automatic Transmission Fluid
It is not necessary to check the transmission
fluid level. A transmission fluid leak is the
only reason for fluid loss. If a leak occurs,
take the vehicle to your dealer and have it
repaired as soon as possible.
Change the fluid at the intervals listed in
Maintenance Schedule 0331, and be sure to
use the transmission fluid listed in
Recommended Fluids and Lubricants 0339.
Caution
Use of the incorrect automatic
transmission fluid may damage the
vehicle, and the damage may not be
covered by the vehicle warranty. Always
use the correct automatic transmission
fluid. See Recommended Fluids and
Lubricants 0339. There is a special procedure for checking and
changing the transmission fluid. Because this
procedure is difficult, this should be done by
your dealer.
Engine Air Filter Life System
If equipped, this feature provides the engine
air filter’s remaining life and best timing for
a change. The timing to change an engine
air filter depends on driving and
environmental conditions.
When to Change the Engine Air Filter
When the Driver Information Center (DIC)
displays a message to replace the engine air
filter at the next oil change, follow this
timing.
When the DIC displays a message to replace
the engine air filter soon, replace the engine
air filter at the earliest convenience.
The system must be reset after the engine
air filter is changed.
If the DIC displays a message to check the
engine air filter system, see your dealer.
How to Reset the Engine Air Filter Life
System
To reset:
1. Place the vehicle in P (Park).
2. Display the Air Filter Life on the DIC. See Driver Information Center (DIC) (Base and
Midlevel) 0100 or
Driver Information Center (DIC) (Uplevel)
0 105.
3. Press
pon the steering wheel to move
to the Reset/Disable display area. Select
Reset then press
V.
4. Press
Vto confirm the reset.
Engine Air Cleaner/Filter
The engine air cleaner/filter is in the engine
compartment on the passenger side of the
vehicle. See Engine Compartment Overview
0 261.
When to Inspect the Engine Air Cleaner/
Filter
If the vehicle is not equipped with the
engine air filter life system, see
Maintenance Schedule 0331.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Vehicle Care 271
If the engine coolant temperature gauge is
in the overheat zone and an overheat DIC
message is displayed with no sign of steam:1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest fan
speed. Open the windows as necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or N (Neutral), and
let the engine idle.
If the engine coolant temperature gauge is
no longer in the overheat zone or an
overheat DIC message no longer displays,
the vehicle can be driven. Continue to drive
the vehicle slowly for about 10 minutes.
Keep a safe distance from the vehicle in
front. If the engine coolant temperature
gauge does not go back to the overheat
zone or an overheat DIC message does not
display, continue to drive normally and have
the cooling system checked for proper fill
and function.
If the engine coolant temperature gauge is
still in the overheat zone or an overheat DIC
message still displays, pull over, stop, and
park the vehicle right away. If overheat
messages appear repeatedly, see your
dealer. If there is no sign of steam, idle the engine
for three minutes while parked. If the
engine coolant temperature gauge is still in
the overheat zone or an overheat DIC
message displays, turn off the engine until
it cools down.
Washer Fluid
What to Use
When windshield washer fluid is needed, be
sure to read the manufacturer's instructions
before use. If operating the vehicle in an
area where the temperature may fall below
freezing, use a fluid that has sufficient
protection against freezing.
Adding Washer Fluid
Open the cap with the washer symbol on it.
Add washer fluid until the tank is full. See
Engine Compartment Overview
0261 for
reservoir location.
Caution
.Do not use washer fluid that contains
any type of water repellent coating.
This can cause the wiper blades to
chatter or skip.
.Do not use engine coolant (antifreeze)
in the windshield washer. It can
damage the windshield washer system
and paint.
.Do not mix water with ready-to-use
washer fluid. Water can cause the
solution to freeze and damage the
washer fluid tank and other parts of
the washer system.
.When using concentrated washer fluid,
follow the manufacturer instructions
for adding water.
.Fill the washer fluid tank only
three-quarters full when it is very cold.
This allows for fluid expansion if
freezing occurs, which could damage
the tank if it is completely full.
Brakes
Disc brake pads have built-in wear indicators
that make a high-pitched warning sound
when the brake pads are worn and new

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
272 Vehicle Care
pads are needed. The sound can come and
go or can be heard all the time when the
vehicle is moving, except when applying the
brake pedal firmly.
{Warning
The brake wear warning sound means
that soon the brakes will not work well.
That could lead to a crash. When the
brake wear warning sound is heard, have
the vehicle serviced.
Caution
Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates can
cause a brake squeal when the brakes are
first applied or lightly applied. This does not
mean something is wrong with the brakes.
Properly torqued wheel nuts are necessary
to help prevent brake pulsation. When tires
are rotated, inspect brake pads for wear and
evenly tighten wheel nuts in the proper
sequence to torque specifications. See
Capacities and Specifications 0343.
Brake pads should be replaced as
complete sets.
Brake Pedal Travel
See your dealer if the brake pedal does not
return to normal height, or if there is a
rapid increase in pedal travel. This could be
a sign that brake service may be required.
Replacing Brake System Parts
Always replace brake system parts with
new, approved replacement parts. If this is
not done, the brakes may not work
properly. The braking performance expected
can change in many other ways if the
wrong replacement brake parts are installed
or if parts are improperly installed.
Brake Fluid
The brake master cylinder reservoir is filled
with GM approved DOT 3 brake fluid as
indicated on the reservoir cap. See Engine
Compartment Overview 0261 for the
location of the reservoir. Checking Brake Fluid
With the vehicle in P (Park) on a level
surface, the brake fluid level should be
between the minimum and maximum marks
on the brake fluid reservoir.
There are only two reasons why the brake
fluid level in the reservoir may go down:
.Normal brake lining wear. When new
linings are installed, the fluid level goes
back up.
.A fluid leak in the brake hydraulic system.
Have the brake hydraulic system fixed.
With a leak, the brakes will not
work well.
Always clean the brake fluid reservoir cap
and the area around the cap before
removing it.
Do not top off the brake fluid. Adding fluid
does not correct a leak. If fluid is added
when the linings are worn, there will be too
much fluid when new brake linings are
installed. Add or remove fluid, as necessary,
only when work is done on the brake
hydraulic system.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
274 Vehicle Care
Vehicle Storage
{Warning
Batteries have acid that can burn you and
gas that can explode. You can be badly
hurt if you are not careful. SeeJump
Starting - North America 0316 for tips on
working around a battery without
getting hurt.
Infrequent Usage: Remove the black,
negative (−) cable from the battery to keep
the battery from running down.
Extended Storage: Remove the black,
negative (−) cable from the battery or use a
battery trickle charger.
All-Wheel Drive
Transfer Case
Under normal driving conditions, transfer
case fluid does not require maintenance
unless there is a fluid leak or unusual noise.
If required, have the transfer case serviced
by your dealer.
Starter Switch Check
{Warning
When you are doing this inspection, the
vehicle could move suddenly. If the
vehicle moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room around the vehicle.
2. Apply both the parking brake and the regular brake.
Do not use the accelerator pedal, and be
ready to turn off the engine immediately
if it starts.
3. Try to start the engine in each gear. The vehicle should start only in P (Park) or
N (Neutral). If the vehicle starts in any
other position, contact your dealer for
service.
Park Brake and P (Park)
Mechanism Check
{Warning
When you are doing this check, the
vehicle could begin to move. You or
others could be injured and property
could be damaged. Make sure there is
room in front of the vehicle in case it
begins to roll. Be ready to apply the
regular brake at once should the vehicle
begin to move.
Park on a fairly steep hill, with the vehicle
facing downhill. Keeping your foot on the
regular brake, set the parking brake.
.To check the parking brake's holding
ability: With the engine running and the
transmission in N (Neutral), slowly remove
foot pressure from the regular brake
pedal. Do this until the vehicle is held by
the parking brake only.
.To check the P (Park) mechanism's holding
ability: With the engine running, shift to
P (Park). Then release the parking brake
followed by the regular brake.
Contact your dealer if service is required.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
282 Vehicle Care
The vehicle may not be equipped with all of
the fuses, relays, and features shown.Fuses Usage
F01 Starter 1
F02 Starter 2
F03 Lambda sensor 1
F04 Engine control module F05 FlexFuel sensor/Aero shutter Fuses Usage
F06 Transmission control module
F07 –
F08 Engine control module
F09 Air conditioning clutch F10 Canister vent solenoid F11 Fuel system
F12 Front heated seats Fuses Usage
F13 Engine coolant pump
F14 –
F15 Lambda sensor 2
F16 Ignition coils F17 Engine control module
F18 –
F19 –
F20 DC DC converter 2 F21 Shift control
F22 Antilock brake pump
F23 Front/Rear washer pump
F24 –
F25 –
F26 –
F27 Antilock brake valves
F28 LD trailer
F29 Rear window defogger
F30 Mirror defroster F31 –
F32 Variable functions

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Vehicle Care 283
FusesUsage
F33 –
F34 Horn F35 –
F36 Right high-beam headlamp
F37 Left high-beam headlamp
F38 Automatic headlamp leveling
F39 Fog lamps
F40 –
F41 Transmission range control module
F42 Motorized headlamp
F43 –
F44 Interior rearview mirror F45 Passenger side ventilated seat
F46 Driver side ventilated seat F47 Steering column lock assembly
F48 Rear wiper Fuses
Usage
F49 –
F50 Heated steering wheel F51 Right daytime running lamp
F52 Engine control module/ Transmission control
F53 –
F54 –
F55 Front wiper speed/ Control
F56 –
F57 Left daytime running lamp
Relays Usage
K01 Starter solenoid
K02 Air conditioning control
K03 Engine control module
K04 Front wiper control K05 Starter solenoid 2
K06 – Relays
Usage
K07 –
K08 –
K09 Front wiper speed K10 –
K11 –
K12 High-beam headlamps
K13 Headlamp/Daytime running lamps
K14 Run/Crank K15 Rear window defogger

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
284 Vehicle Care
Instrument Panel Fuse Block
The instrument panel fuse block is under the
instrument panel on the driver side.
To access the fuses, press and release the
latch near the top center square.
Apply pressure to the two retaining tabs on
the sides of the cover, until the two
retaining tabs clear the sides of the
instrument panel. Allow the panel to move
downward and out of the way.
To reinstall the cover, reverse the steps.
The vehicle may not be equipped with all of
the fuses and relays shown.
FusesUsage
F01 DC AC inverter
F02 Front windows Fuses
Usage
F03 Trailer brake
F04 Heating, ventilation, and air conditioning blower
F05 –
F06 Central gateway module F07 –
F08 Body control module 3
F09 Amplifier F10 –
F11 –
F12 –
F13 –
F14 Electronic shifter F15 Transmission control module
F16 Front heated seats F17 Left data link connector
F18 Body control module 7
F19 Exterior mirror
F20 –

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Vehicle Care 285
FusesUsage
F21 Body control module 4
F22 –
F23 –
F24 Sensing and diagnostic module
F25 Occupancy sensor
F26 –
F27 Power seats
F28 Rear windows
F29 –
F30 Front heated seats switch F31 Steering wheel controls
F32 Body control module 8
F33 Heating, ventilation, and air conditioning
F34 Passive entry, passive start
F35 Liftgate latch
F36 Wireless charger module/ USB accessory
F37 Cigarette lighter Fuses
Usage
F38 OnStar
F39 Instrument panel USB
F40 Camera module/Liftgate module
F41 Park assist module/Center stack display/Heating,
ventilation and air
conditioner display/
Universal garage door
opener/Overhead control
switchbank
F42 Radio
Relays Usage
K01 –
K02 Retained accessory power
K03 Liftgate
K04 –
K05 –
Circuit Breakers Usage CB1 –
CB2 –Rear Compartment Fuse Block
The rear compartment fuse block is behind a
trim panel on the side of the rear
compartment.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Vehicle Care 287
FusesUsage
F21 Rear auxiliary power outlet
F22 Rear drive unit
Relays Usage
K1 Right trailer stoplamp/ Turn signal lamp
K2 Trailer reverse lamps
K3 Left trailer stoplamp/ Turn signal lamp
K4 Park lamps K5 –
Wheels and Tires
Tires
Every new GM vehicle has high-quality
tires made by a leading tire
manufacturer. See the warranty manual
for information regarding the tire
warranty and where to get service. For
additional information refer to the tire
manufacturer.
{Warning
.Poorly maintained and improperly
used tires are dangerous.
.Overloading the tires can cause
overheating as a result of too
much flexing. There could be a
blowout and a serious crash. See
Vehicle Load Limits 0196.
.Underinflated tires pose the same
danger as overloaded tires. The
resulting crash could cause serious
injury. Check all tires frequently to
maintain the recommended
pressure. Tire pressure should be
checked when the tires are cold.
.Overinflated tires are more likely
to be cut, punctured, or broken by
a sudden impact —such as when
hitting a pothole. Keep tires at the
recommended pressure.
.Worn or old tires can cause a
crash. If the tread is badly worn,
replace them.
(Continued)
Warning (Continued)
.Replace any tires that have been
damaged by impacts with
potholes, curbs, etc.
.Improperly repaired tires can cause
a crash. Only the dealer or an
authorized tire service center
should repair, replace, dismount,
and mount the tires.
.Do not spin the tires in excess of
56 km/h (35 mph) on slippery
surfaces such as snow, mud, ice,
etc. Excessive spinning may cause
the tires to explode.
All-Season Tires
This vehicle may come with all-season tires.
These tires are designed to provide good
overall performance on most road surfaces
and weather conditions. Original equipment
tires designed to GM's specific tire
performance criteria have a TPC specification
code molded onto the sidewall. Original
equipment all-season tires can be identified
by the last two characters of this TPC code,
which will be “MS.”