
GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
Seats and Restraints 69
{Warning
For up to 10 seconds after the
vehicle is turned off and the
battery is disconnected, an airbag
can still inflate during improper
service. You can be injured if you
are close to an airbag when it
inflates. Avoid yellow connectors.
They are probably part of the
airbag system. Be sure to follow
proper service procedures, and
make sure the person performing
work for you is qualified to do so.
Adding Equipment to the
Airbag-Equipped Vehicle
Adding accessories that change the
vehicle's frame, bumper system,
height, front end, or side sheet
metal may keep the airbag system
from working properly.
The operation of the airbag system
can also be affected by changing,
including improperly repairing or
replacing, any parts of the following:.
Airbag system, including airbag
modules, front or side impact
sensors, sensing and diagnostic
module, or airbag wiring
. Front seats, including stitching,
seams or zippers
. Seat belts
. Steering wheel, instrument
panel, overhead console, ceiling
trim, or pillar garnish trim
. Inner door seals, including
speakers
Your dealer and the service manual
have information about the location
of the airbag modules and sensors,
sensing and diagnostic module, and
airbag wiring along with the proper
replacement procedures.
In addition, the vehicle has a
passenger sensing system for the
front outboard passenger position,
which includes sensors that are part
of the passenger seat. The
passenger sensing system may not
operate properly if the original seat
trim is replaced with non-GM
covers, upholstery, or trim; or with GM covers, upholstery, or trim
designed for a different vehicle. Any
object, such as an aftermarket seat
heater or a comfort-enhancing pad
or device, installed under or on top
of the seat fabric, could also
interfere with the operation of the
passenger sensing system. This
could either prevent proper
deployment of the passenger
airbag(s) or prevent the passenger
sensing system from properly
turning off the passenger airbag(s).
See
Passenger Sensing System
0 64.
If the vehicle has rollover roof-rail
airbags, see Different Size Tires
and Wheels 0331 for additional
important information.
If the vehicle must be modified
because you have a disability and
have questions about whether the
modifications will affect the vehicle's
airbag system, or if you have
questions about whether the airbag
system will be affected if the vehicle
is modified for any other reason, call
Customer Assistance. See
Customer Assistance Offices 0387.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
70 Seats and Restraints
Airbag System Check
The airbag system does not need
regularly scheduled maintenance or
replacement. Make sure the airbag
readiness light is working. See
Airbag Readiness Light0113.
Caution
If an airbag covering is damaged,
opened, or broken, the airbag
may not work properly. Do not
open or break the airbag
coverings. If there are any
opened or broken airbag
coverings, have the airbag
covering and/or airbag module
replaced. For the location of the
airbags, see Where Are the
Airbags? 060. See your dealer
for service.
Replacing Airbag System
Parts after a Crash
{Warning
A crash can damage the airbag
systems in the vehicle.
A damaged airbag system may
not properly protect you and your
passenger(s) in a crash, resulting
in serious injury or even death. To
help make sure the airbag
systems are working properly
after a crash, have them
inspected and any necessary
replacements made as soon as
possible.
If an airbag inflates, you will need to
replace airbag system parts. See
your dealer for service.
If the airbag readiness light stays on
after the vehicle is started or comes
on when you are driving, the airbag
system may not work properly. Have
the vehicle serviced right away. See
Airbag Readiness Light 0113.
Child Restraints
Older Children
Older children who have outgrown
booster seats should wear the
vehicle’s seat belts.
The manufacturer instructions that
come with the booster seat state the
weight and height limitations for that
booster. Use a booster seat with a
lap-shoulder belt until the child
passes the fit test below:

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
82 Seats and Restraints
According to accident statistics,
children and infants are safer when
properly restrained in a child
restraint system or infant restraint
system secured in a rear seating
position. SeeWhere to Put the
Restraint 076 for additional
information.
Securing a Child Restraint
Designed for the LATCH
System
{Warning
A child could be seriously injured
or killed in a crash if the child
restraint is not properly attached
to the vehicle using either the
LATCH anchors or the vehicle
seat belt. Follow the instructions
that came with the child restraint
and the instructions in this
manual.
{Warning
To reduce the risk of serious or
fatal injuries during a crash, do
not attach more than one child
restraint to a single anchor.
Attaching more than one child
restraint to a single anchor could
cause the anchor or attachment
to come loose or even break
during a crash. A child or others
could be injured.
{Warning
Children can be seriously injured
or strangled if a shoulder belt is
wrapped around their neck. The
shoulder belt can tighten but
cannot be loosened if it is locked.
The shoulder belt locks when it is
pulled all the way out of the
retractor. It unlocks when the
shoulder belt is allowed to go all
the way back into the retractor,
(Continued)
Warning (Continued)
but it cannot do this if it is
wrapped around a child’s neck.
If the shoulder belt is locked and
tightened around a child’s neck,
the only way to loosen the belt is
to cut it.
Buckle any unused seat belts
behind the child restraint so
children cannot reach them. Pull
the shoulder belt all the way out
of the retractor to set the lock,
and tighten the belt behind the
child restraint after the child
restraint has been installed.
Caution
Do not let the LATCH
attachments rub against the
vehicle’s seat belts. This may
damage these parts. If necessary,
move buckled seat belts to avoid
rubbing the LATCH attachments.(Continued)

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
84 Seats and Restraints
are using a dual tether,
route the tether over the
seatback.
.If the position you are using
has an adjustable headrest
or head restraint and you
are using a dual tether,
raise the headrest or head
restraint and route the
tether under the headrest or
head restraint and in
between the headrest or
head restraint posts.
.
If the position you are using
has an adjustable headrest
or head restraint and you
are using a single tether,
raise the headrest or head
restraint and route the
tether under the headrest or
head restraint and in
between the headrest or
head restraint posts.
3. Before placing a child in the child restraint, make sure it is
securely held in place. To
check, grasp the child restraint
at the LATCH path and attempt
to move it side to side and
back and forth. There should
be no more than 2.5 cm (1 in) of
movement, for proper
installation.
Replacing LATCH System
Parts After a Crash
{Warning
A crash can damage the LATCH
system in the vehicle. A damaged
LATCH system may not properly
secure the child restraint,
resulting in serious injury or even
death in a crash. To help make
sure the LATCH system is
working properly after a crash,
see your dealer to have the
system inspected and any
necessary replacements made as
soon as possible.
If the vehicle has the LATCH system
and it was being used during a
crash, new LATCH system parts
may be needed.
New parts and repairs may be
necessary even if the LATCH
system was not being used at the
time of the crash.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
158 Climate Controls
Air Vents
Use the louvers located on the air
vents to change the direction of the
airflow.
To open or close off the airflow:
.On the center air vents, move
the slider knobs up or down.
. On the outer and rear air vents,
move the slider knobs right
or left.
Operation Tips
. Clear away any ice, snow,
or leaves from air inlets at the
base of the windshield that could
block the flow of air into the
vehicle.
. Clear snow off the hood to
improve visibility and help
decrease moisture drawn into
the vehicle, which may improve
long term system performance. .
Keep the path under the front
seats clear of objects to help
circulate the air inside of the
vehicle more effectively.
. Use of non-GM approved hood
deflectors can adversely affect
the performance of the system.
Check with your dealer before
adding equipment to the outside
of the vehicle.
. Do not attach any devices to the
air vent slats. This restricts
airflow and may cause damage
to the air vents.
Maintenance
Passenger Compartment
Air Filter
The filter removes dust, pollen, and
other airborne irritants from outside
air that is pulled into the vehicle.
The filter should be replaced as part
of routine scheduled maintenance.
See Maintenance Schedule 0368.
To find out what type of filter to use,
see Maintenance Replacement
Parts 0378.
1. Open the glove box.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
Driving and Operating 171
braking. Drive at a reduced speed
and avoid sharp turns or abrupt
maneuvers.
Traction is reduced on hard packed
snow and ice and it is easy to lose
control. Reduce vehicle speed when
driving on hard packed snow
and ice.
{Warning
Driving on frozen lakes, ponds,
or rivers can be dangerous. Ice
conditions vary greatly and the
vehicle could fall through the ice;
you and your passengers could
drown. Drive your vehicle on safe
surfaces only.
Driving in Water
{Warning
Driving through rushing water can
be dangerous. Deep water can
sweep your vehicle downstream
and you and your passengers(Continued)
Warning (Continued)
could drown. If it is only shallow
water, it can still wash away the
ground from under your tires.
Traction could be lost, and the
vehicle could roll over. Do not
drive through rushing water.
Caution
Do not drive through standing
water if it is deep enough to cover
the wheel hubs, axles, or exhaust
pipe. Deep water can damage the
axle and other vehicle parts.
If the standing water is not too deep,
drive through it slowly. At faster
speeds, water can get into the
engine and cause it to stall. Stalling
can occur if the exhaust pipe is
under water. Do not turn off the
ignition when driving through water.
If the exhaust pipe is under water,
the engine will not start. When going through water, the brakes get wet
and it may take longer to stop. See
Driving on Wet Roads
0171.
After Off-Road Driving
Remove any brush or debris that
has collected on the underbody or
chassis, or under the hood. These
accumulations can be a fire hazard.
After operation in mud or sand,
have the brake linings cleaned and
checked. These substances can
cause glazing and uneven braking.
Check the body structure, steering,
suspension, wheels, tires, and
exhaust system for damage and
check the fuel lines and cooling
system for any leakage.
More frequent maintenance service
is required. See the Maintenance
Schedule 0368.
Driving on Wet Roads
Rain and wet roads can reduce
vehicle traction and affect your
ability to stop and accelerate.
Always drive slower in these types

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
Driving and Operating 181
{Warning
Turning off the vehicle while
moving may cause loss of power
assist in the brake and steering
systems and disable the airbags.
While driving, only shut the
vehicle off in an emergency.
If the vehicle cannot be pulled over
and must be shut off while driving,
press and hold ENGINE START/
STOP for longer than two seconds,
or press twice in five seconds.
ACC/ACCESSORY (Amber
Indicator Light) : This mode allows
you to use some electrical
accessories when the engine is off.
With the ignition off, pressing the
button one time without the brake
pedal applied will place the ignition
system in ACC/ACCESSORY.
The ignition will switch from ACC/
ACCESSORY to OFF after
five minutes to prevent battery
rundown. ON/RUN/START (Green Indicator
Light) :
This mode is for starting
and driving. With the ignition off and
the brake pedal applied, pressing
the button once will turn the ignition
on. Once engine cranking begins,
release the button. Engine cranking
will continue until the engine starts.
See Starting the Engine 0181. The
ignition will then remain in on.
Service Mode
This power mode is available for
service and diagnostics, and to
verify the proper operation of the
malfunction indicator lamp as may
be required for emission inspection
purposes. With the vehicle off and
the brake pedal not applied,
pressing and holding ENGINE
START/STOP for more than
five seconds will place the vehicle in
Service Mode. The instruments and
audio systems will operate as they
do in ON/RUN, but the vehicle will
not be able to be driven. The engine
will not start in Service Mode. Press
ENGINE START/STOP again to turn
the vehicle off.
Starting the Engine
Shift the vehicle into P (Park) or
N (Neutral). To restart the engine
when the vehicle is already moving,
use N (Neutral) only.
Caution
Do not try to shift to P (Park) if the
vehicle is moving. If you do, you
could damage the transmission.
Shift to P (Park) only when the
vehicle is stopped.
Caution
If you add electrical parts or
accessories, you could change
the way the engine operates. Any
resulting damage would not be
covered by the vehicle warranty.
See Add-On Electrical Equipment
0 271.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
182 Driving and Operating
Gasoline Engine Starting
Procedure1. With the Keyless Access system, the Remote Keyless
Entry (RKE) transmitter must
be in the vehicle. Press
ENGINE START/STOP with the
brake pedal applied. When the
engine begins cranking, let go
of the button.
The idle speed will go down as
the engine gets warm. Do not
race the engine immediately
after starting it.
If the RKE transmitter is not in
the vehicle, if there is
interference, or if the RKE
battery is low, a Driver
Information Center (DIC) will
display a message. See
Remote Keyless Entry (RKE)
System Operation 08.Caution
Cranking the engine for long
periods of time, by trying to start
the engine immediately after
cranking has ended, can overheat
and damage the cranking motor,
and drain the battery. Wait at
least 15 seconds between each
try, to let the cranking motor
cool down.
2. If the engine does not start after five to 10 seconds,
especially in very cold weather
(below −18 °C or 0 °F), it could
be flooded with too much
gasoline. Try pushing the
accelerator pedal all the way to
the floor and holding it there as
you press ENGINE START/
STOP. Wait at least 15 seconds
between each try, to allow the
cranking motor to cool down.
When the engine starts,
release the accelerator. If the
vehicle starts briefly but then
stops again, do the same thing. This clears the extra gasoline
from the engine. Do not race
the engine immediately after
starting it. Operate the engine
and transmission gently until
the oil warms up and lubricates
all moving parts.
Diesel Engine Starting Procedure
The diesel engine starts differently
than a gasoline engine. 1. With the Keyless Access system, the RKE transmitter
must be in the vehicle. Press
ENGINE START/STOP with the
brake pedal applied to start. If it
is too cold, the wait-to-start
light will come on and there will
be a short delay before
starting. See Wait-to-Start Light
0 121. This light may not come
on if the engine is warm.
The engine has a fast warm-up
glow plug system. The
wait-to-start light will illuminate
for a much shorter time than
most diesel engines, due to the
rapid heating of the glow plug
system.