Start stop GMC TERRAIN 2021 Owner's Guide

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
190 Driving and Operating
Loss of Control
Skidding
There are three types of skids that
correspond to the vehicle's three control
systems:
.Braking Skid—wheels are not rolling.
.Steering or Cornering Skid —too much
speed or steering in a curve causes tires
to slip and lose cornering force.
.Acceleration Skid —too much throttle
causes the driving wheels to spin.
Defensive drivers avoid most skids by taking
reasonable care suited to existing conditions,
and by not overdriving those conditions. But
skids are always possible.
If the vehicle starts to slide, follow these
suggestions:
.Ease your foot off the accelerator pedal
and steer the way you want the vehicle
to go. The vehicle may straighten out. Be
ready for a second skid if it occurs.
.Slow down and adjust your driving
according to weather conditions. Stopping
distance can be longer and vehicle control
can be affected when traction is reduced
by water, snow, ice, gravel, or other
material on the road. Learn to recognize warning clues
—such as enough water,
ice, or packed snow on the road to make
a mirrored surface —and slow down
when you have any doubt.
.Try to avoid sudden steering, acceleration,
or braking, including reducing vehicle
speed by shifting to a lower gear. Any
sudden changes could cause the tires to
slide.
Remember: Antilock brakes help avoid only
the braking skid.
Off-Road Driving
All-wheel-drive vehicles can be used for
off-road driving. Vehicles without all-wheel
drive and vehicles not equipped with All
Terrain (AT) or On-Off Road (OOR) tires must
not be driven off-road except on a level,
solid surface. To contact the tire
manufacturer for more information about
the original equipment tires, see the
warranty manual.
Controlling the vehicle is the key to
successful off-road driving. One of the best
ways to control the vehicle is to control the
speed.
{Warning
When driving off-road, bouncing and
quick changes in direction can easily
throw you out of position. This could
cause you to lose control and crash. You
and your passengers should always wear
seat belts.
Before Driving Off-Road
.Have all necessary maintenance and
service work completed.
.Fuel the vehicle, fill fluid levels, and check
inflation pressure in all tires, including the
spare, if equipped.
.Read all the information about
all-wheel-drive vehicles in this manual.
.Make sure all underbody shields,
if equipped, are properly attached.
.Know the local laws that apply to off-road
driving.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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192 Driving and Operating
Warning (Continued)
you or others could be injured or killed.
Apply the brakes lightly when descending
a hill and use a low gear to keep vehicle
speed under control.
If the vehicle stalls on a hill: 1. Apply the brakes to stop the vehicle, and then apply the parking brake.
2. Shift into P (Park) and then restart the engine.
.If driving uphill when the vehicle
stalls, shift to R (Reverse), release the
parking brake, and back
straight down.
.Never try to turn the vehicle around.
If the hill is steep enough to stall the
vehicle, it is steep enough to cause it
to roll over.
.If you cannot make it up the hill,
back straight down the hill.
.Never back down a hill in N (Neutral)
using only the brake. The vehicle can
roll backward quickly and you could
lose control.
.If driving downhill when the vehicle
stalls, shift to a lower gear, release
the parking brake, and drive straight
down the hill.
3. If the vehicle cannot be restarted after stalling, set the parking brake, shift into
P (Park), and turn the vehicle off.
3.1. Leave the vehicle and seek help.
3.2. Stay clear of the path the vehicle would take if it rolled downhill.
.Avoid turns that take the vehicle across
the incline of the hill. A hill that can be
driven straight up or down might be too
steep to drive across. Driving across an
incline puts more weight on the downhill
wheels which could cause a downhill slide
or a rollover.
.Surface conditions can be a problem.
Loose gravel, muddy spots, or even wet
grass can cause the tires to slip sideways,
downhill. If the vehicle slips sideways, it
can hit something that will trip it —a
rock, a rut, etc. —and roll over.
.Hidden obstacles can make the steepness
of the incline more severe. If a rock is
driven across with the uphill wheels, or if
the downhill wheels drop into a rut or
depression, the vehicle can tilt even more.
.If an incline must be driven across, and
the vehicle starts to slide, turn downhill.
This should help straighten out the
vehicle and prevent the side slipping.
{Warning
Getting out of the vehicle on the
downhill side when stopped across an
incline is dangerous. If the vehicle rolls
over, you could be crushed or killed.
Always get out on the uphill side of the
vehicle and stay well clear of the
rollover path.
Driving in Mud, Sand, Snow, or Ice
Use a low gear when driving in mud —the
deeper the mud, the lower the gear. Keep
the vehicle moving to avoid getting stuck.
Traction changes when driving on sand. On
loose sand, such as on beaches or sand
dunes, the tires tend to sink into the sand.
This affects steering, accelerating, and
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.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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Driving and Operating 193
{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 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
0193.
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
0 331.
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 of driving conditions and avoid driving
through large puddles and deep-standing or
flowing water.
{Warning
Wet brakes can cause crashes. They
might not work as well in a quick stop
and could cause pulling to one side. You
could lose control of the vehicle.
After driving through a large puddle of
water or a car/vehicle wash, lightly apply
the brake pedal until the brakes work
normally.
Flowing or rushing water creates strong
forces. Driving through flowing water
could cause the vehicle to be carried
away. If this happens, you and other
vehicle occupants could drown. Do not
ignore police warnings and be very
cautious about trying to drive through
flowing water.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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Driving and Operating 195
.Allow greater following distance and
watch for slippery spots. Icy patches can
occur on otherwise clear roads in shaded
areas. The surface of a curve or an
overpass can remain icy when the
surrounding roads are clear. Avoid sudden
steering maneuvers and braking while
on ice.
.Turn off cruise control.
Blizzard Conditions
Stop the vehicle in a safe place and signal
for help. Stay with the vehicle unless there
is help nearby. If possible, use Roadside
Assistance. SeeRoadside Assistance Program
0 349. To get help and keep everyone in the
vehicle safe:
.Turn on the hazard warning flashers.
.Tie a red cloth to an outside mirror.
{Warning
Snow can trap engine exhaust under the
vehicle. This may cause exhaust gases to
get inside. Engine exhaust contains
carbon monoxide (CO), which cannot be
seen or smelled. It can cause
unconsciousness and even death.
(Continued)
Warning (Continued)
If the vehicle is stuck in snow:
.Clear snow from the base of the
vehicle, especially any blocking the
exhaust pipe.
.Open a window about 5 cm (2 in) on
the vehicle side that is away from the
wind, to bring in fresh air.
.Fully open the air outlets on or under
the instrument panel.
.Adjust the climate control system to
circulate the air inside the vehicle and
set the fan speed to the highest
setting. See“Climate Control Systems.”
For more information about CO, see
Engine Exhaust 0207.
To save fuel, run the engine for short
periods to warm the vehicle and then shut
the engine off and partially close the
window. Moving about to keep warm also
helps.
If it takes time for help to arrive, when
running the engine, push the accelerator
pedal slightly so the engine runs faster than
the idle speed. This keeps the battery charged to restart the vehicle and to signal
for help with the headlamps. Do this as
little as possible, to save fuel.
If the Vehicle Is Stuck
Slowly and cautiously spin the wheels to
free the vehicle when stuck in sand, mud,
ice, or snow.
If stuck too severely for the traction system
to free the vehicle, turn the traction system
off and use the rocking method. See
Traction Control/Electronic Stability Control
0
214.
{Warning
If the vehicle's tires spin at high speed,
they can explode, and you or others
could be injured. The vehicle can
overheat, causing an engine compartment
fire or other damage. Spin the wheels as
little as possible and avoid going above
56 km/h (35 mph).
Rocking the Vehicle to Get it Out
Turn the steering wheel left and right to
clear the area around the front wheels. Turn
off any traction system. Shift back and forth
between R (Reverse) and a low forward gear,

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Driving and Operating 199
Warning (Continued)
.Never stack heavier things, like
suitcases, inside the vehicle so
that some of them are above the
tops of the seats.
.Do not leave an unsecured child
restraint in the vehicle.
.Secure loose items in the vehicle.
.Do not leave a seat folded down
unless needed.
Starting and Operating
New Vehicle Break-In
Caution
The vehicle does not need an elaborate
break-in. But it will perform better in the
long run if you follow these guidelines:
.Do not drive at any one constant
speed, fast or slow, for the first
800 km (500 mi). Do not make
full-throttle starts. Avoid downshifting
to brake or slow the vehicle.
(Continued)
Caution (Continued)
.Avoid making hard stops for the first
300 km (200 mi) or so. During this
time the new brake linings are not yet
broken in. Hard stops with new linings
can mean premature wear and earlier
replacement. Follow this breaking-in
guideline every time you get new
brake linings.
Following break-in, engine speed and load
can be gradually increased.
Ignition Positions
The vehicle has an electronic keyless ignition
with pushbutton start. The Remote Keyless Entry (RKE) transmitter
must be in the vehicle for the system to
operate. If the pushbutton start is not
working, the vehicle may be near a strong
radio antenna signal causing interference to
the Keyless Access system. See
Remote
Keyless Entry (RKE) System Operation 07.
To shift out of P (Park), the engine must be
turned on, and the brake pedal must be
applied. See Shifting out of Park 0205.
Stopping the Engine/Off (No Indicator
Lights) : When the vehicle is stopped, press
ENGINE START/STOP once to turn the
engine off.
If the vehicle is in P (Park), the ignition will
turn off, and Retained Accessory Power
(RAP) will remain active. See Retained
Accessory Power (RAP) 0204.
If the vehicle is in R (Reverse), D (Drive) or
L (Low), the vehicle will shift to P (Park), the
ignition will turn off, and Retained Accessory
Power (RAP) will remain active. See Retained
Accessory Power (RAP) 0204.
If the vehicle is in N (Neutral), the ignition
will return to ACC/ACCESSORY and display
the message SHIFT TO PARK in the Driver

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
200 Driving and Operating
Information Center (DIC). When the vehicle
is shifted into P (Park), the ignition system
will turn off.
The vehicle may have an electric steering
column lock. The lock is activated when the
vehicle is turned off and either front door is
opened. A sound may be heard as the lock
actuates or releases. The steering column
lock may not release with the wheels turned
off center. If this happens, the vehicle may
not start. Move the steering wheel from left
to right while attempting to start the
vehicle. If this does not work, the vehicle
needs service.
Do not turn the engine off when the vehicle
is moving. This will cause a loss of power
assist in the brake and steering systems and
disable the airbags.
If the vehicle must be turned off in an
emergency:1. Brake using a firm and steady pressure. Do not pump the brakes repeatedly. This
may deplete power assist, requiring
increased brake pedal force. 2. Shift the vehicle to N (Neutral). This can
be done while the vehicle is moving.
After shifting to N (Neutral), firmly apply
the brakes and steer the vehicle to a
safe location.
3. Come to a complete stop and shift to P (Park).
4. Set the parking brake. See Electric
Parking Brake 0212. Press ENGINE
START/STOP to turn the vehicle off.
{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 0201. 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

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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Driving and Operating 201
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.
SeeAdd-On Electrical Equipment 0256.
1. 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
07.
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.
Stop/Start System
This vehicle has a Stop/Start system to shut
off the engine to help conserve fuel. It has
components designed for the increased
number of starts.
{Warning
The automatic engine Stop/Start feature
causes the engine to shut off while the
vehicle is still on. Do not exit the vehicle
before shifting to P (Park). The vehicle
may restart and move unexpectedly.
Always shift to P (Park), and then turn
the ignition off before exiting the vehicle.
Auto Engine Stop/Start
When the brakes are applied and the vehicle
is at a complete stop, the engine may turn
off. When stopped, the tachometer displays
AUTO STOP. See Tachometer090. When

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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202 Driving and Operating
the brake pedal is released or the
accelerator pedal is pressed, the engine will
restart.
To maintain vehicle performance, other
conditions may cause the engine to
automatically restart before the brake pedal
is released.
Auto Stops may not occur and/or auto
restarts may occur because:
.The climate control settings require the
engine to be running to cool or heat the
vehicle interior.
.The vehicle battery charge is low.
.The vehicle battery has recently been
disconnected.
.Minimum vehicle speed has not been
reached since the last Auto Stop
.The accelerator pedal is pressed.
.The engine or transmission is not at the
required operating temperature.
.The outside temperature is not in the
required operating range.
.The vehicle is shifted out of D (Drive) to
any gear other than P (Park).
.Tow/Haul Mode or other driver modes
have been selected.
.The vehicle is on a steep hill or grade.
.The driver door has been opened or driver
seat belt has been unbuckled.
.The hood has been opened.
.The Auto Stop has reached the maximum
allowed time.
Winter Cover
If equipped, the winter cover can be used to
enhance heater performance in extremely
cold conditions below−0 °C (32 °F). The
winter cover installs over the grille and
restricts airflow to the engine compartment.
Usage Guidelines
The winter cover should only be used while
operating the vehicle in extremely cold
temperatures or in heavy snow for extended
periods. In these temperatures, the vehicle
does not need a large amount of air to
properly cool the engine. When more
airflow is required to cool the vehicle, the
winter cover should not be used. The
following usage guidelines will allow
adequate airflow for proper radiator and air
cooler performance:
.Do not use the winter cover if towing a
trailer. The vehicle may overheat if the
radiator is covered while towing.
.Do not modify the cover. The winter
cover does not cover some sections of the
front of the vehicle to provide enough
airflow.
.Keep the underside of the winter cover as
clean as possible. Remove monthly or as
necessary and clean away dust and
debris.
.Do not use the winter cover above −0 °C
(32 °F).
Use only a mild soap to clean. Do not use
harsh soap, strong detergents, or vinyl
protectant/sealant type products as they
may damage the special finish. Allow the
winter cover to dry completely before
reinstalling.
Installation Instructions
When first trying to fit the cover, it may
appear to be undersized but will stretch
during installation to ensure a tight fit. The
initial installation of the cover is best
performed when the winter cover is warm.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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208 Driving and Operating
Warning (Continued)
If unusual fumes are detected or if it is
suspected that exhaust is coming into the
vehicle:
.Drive it only with the windows
completely down.
.Have the vehicle repaired immediately.
Never park the vehicle with the engine
running in an enclosed area such as a
garage or a building that has no fresh air
ventilation.
Running the Vehicle While Parked
It is better not to park with the engine
running.
If the vehicle is left with the engine running,
follow the proper steps to be sure the
vehicle will not move. See Shifting Into Park
0 204 and
Engine Exhaust 0207.
If parking on a hill and pulling a trailer, see
Driving Characteristics and Towing Tips
0 249.
Automatic Transmission
The shift switches are on the center stack.
The selected gear position will illuminate red
on the shift switch, while all others will be
displayed in white. If the shift is not
immediate, as in very cold conditions, the
indicator on the shift switch may blink until
it is fully engaged.
The transmission does not operate when the
vehicle is off.
If the vehicle is in ACC/ACCESSORY, the
transmission can be shifted into P (Park). If ENGINE START/STOP is pressed twice while
at a relatively high speed, the engine will
turn off and the transmission will
automatically shift to N (Neutral). Once the
vehicle is stopped, P (Park) can be selected.
P :
This position locks the drive wheels. Use
P (Park) when starting the vehicle to ensure
the vehicle does not move.
{Warning
It is dangerous to get out of the vehicle
if the transmission is not in P (Park) with
the parking brake set. The vehicle
can roll.
Do not leave the vehicle when the engine
is running. If the engine has been left
running, the vehicle can move suddenly.
You or others could be injured. To be
sure the vehicle will not move, even
when on fairly level ground, always set
the parking brake and place the
transmission into P (Park). See Shifting
Into Park 0204 and
Driving Characteristics and Towing Tips
0 249.

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Driving and Operating 209
This vehicle is equipped with an electronic
transmission. The R (Reverse) and D (Drive)
shift switches are designed to prevent
inadvertent shifting out of P (Park) unless
the ignition is on, and the brake pedal is
applied.
When the vehicle is stopped, press ENGINE
START/STOP to turn off the vehicle. The
transmission will shift to P (Park)
automatically.
The vehicle will not shift into P (Park) if it is
moving too fast. Stop the vehicle and shift
into P (Park).
To shift in and out of P (Park), seeShifting
Into Park 0204 and
Shifting out of Park 0205.
R : Use this gear to back up.
If the vehicle is shifted from either
R (Reverse) to D (Drive), or D (Drive) to
R (Reverse) while the speed is too high, the
vehicle will shift to N (Neutral). Reduce the
vehicle speed and try the shift again.
To shift into R (Reverse): 1. Bring the vehicle to a complete stop.
2. Pull the R (Reverse) switch on the center stack. To shift out of R (Reverse):
1. Bring the vehicle to a complete stop.
2. Shift to the desired gear.
At low vehicle speeds, R (Reverse) can be
used to rock the vehicle back and forth to
get out of snow, ice, or sand without
damaging the transmission. See If the
Vehicle Is Stuck 0195.
N : In this position, the engine does not
connect with the wheels. To restart the
engine when the vehicle is already moving,
use N (Neutral) only.
{Warning
Shifting into a drive gear while the
engine is running at high speed is
dangerous. Unless your foot is firmly on
the brake pedal, the vehicle could move
very rapidly. You could lose control and
hit people or objects. Do not shift into a
drive gear while the engine is running at
high speed.
Caution
Shifting out of P (Park) or N (Neutral) with
the engine running at high speed may
damage the transmission. The repairs
would not be covered by the vehicle
warranty. Be sure the engine is not
running at high speed when shifting the
vehicle.
Caution
The vehicle is not designed to stay in
N (Neutral) for extended periods of time.
It will automatically shift into P (Park).
To shift into N (Neutral), press the
N (Neutral) switch until the N indicator
displays.
To shift out of N (Neutral): 1. Bring the vehicle to a complete stop.
2. Shift to the desired gear.
Car Wash Mode
This vehicle includes a Car Wash Mode that
allows the vehicle to remain in N (Neutral)
for use in automatic car washes.