2021 GMC TERRAIN Auto engine stop start

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
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.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
210 Driving and Operating
Car Wash Mode is not to be used for vehicle
towing. If the vehicle needs to be towed,
seeTowing the Vehicle 0318
Caution
The vehicle is not designed to stay in
N (Neutral) for extended periods of time.
It will automatically shift into P (Park) if
left in Car Wash Mode.
Car Wash Mode (Engine Off –Driver in
Vehicle)
To place the vehicle in N (Neutral) with the
engine off and the vehicle occupied:
1. Drive to the entrance of the car wash.
2. Apply the brake pedal.
3. Shift to N (Neutral).
4. Turn off the engine and release the brake pedal.
5. The indicator should continue to show N. If it does not, start the engine and
repeat Steps 2–4.
6. The vehicle is now ready for the car wash. Car Wash Mode (Engine Off
–Driver out of
Vehicle)
To place the vehicle in N (Neutral) with the
engine off and the vehicle unoccupied:
1. Drive to the entrance of the car wash.
2. Apply the brake pedal.
3. Open the door.
4. Shift to N (Neutral).
5. Turn off the engine and release the brake pedal.
6. The indicator should continue to show N. If it does not, start the engine and
repeat Steps 2–5.
7. Exit the vehicle and close the door. The vehicle is now ready for the car wash.
8. The vehicle may automatically shift to P (Park) upon re-entry.
Car Wash Mode (Engine On –Driver in
Vehicle)
To place the vehicle in N (Neutral) with the
engine on and the vehicle occupied:
1. Drive to the entrance of the car wash.
2. Apply the brake pedal.
3. Shift to N (Neutral).
4. Release the brake pedal. The vehicle is now ready for the car wash. Car Wash Mode (Engine On
–Driver out of
Vehicle)
To place the vehicle in N (Neutral) with the
engine on and the vehicle unoccupied:
1. Drive to the entrance of the car wash.
2. Apply the brake pedal.
3. Open the door.
4. Shift to N (Neutral), then release the brake pedal.
5. The indicator should continue to show N. If it does not, repeat Steps 2–4.
6. Exit the vehicle and close the door. The vehicle is now ready for the car wash.
7. The vehicle may automatically shift to P (Park) upon re-entry.
Caution
A transmission hot message may display
if the automatic transmission fluid is too
hot. Driving under this condition can
damage the vehicle. Stop and idle the
engine to cool the automatic
transmission fluid. This message clears
when the transmission fluid has cooled
sufficiently.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
214 Driving and Operating
Brake Assist
Brake Assist detects rapid brake pedal
applications due to emergency braking
situations and provides additional braking to
activate the Antilock Brake System (ABS) if
the brake pedal is not pushed hard enough
to activate ABS normally. Minor noise, brake
pedal pulsation, and/or pedal movement
during this time may occur. Continue to
apply the brake pedal as the driving
situation dictates. Brake Assist disengages
when the brake pedal is released.
Hill Start Assist (HSA)
{Warning
Do not rely on the HSA feature. HSA does
not replace the need to pay attention
and drive safely. You may not hear or
feel alerts or warnings provided by this
system. Failure to use proper care when
driving may result in injury, death,
or vehicle damage. SeeDefensive Driving
0 187.
When the vehicle is stopped on a grade, Hill
Start Assist (HSA) prevents the vehicle from
rolling in an unintended direction during the
transition from brake pedal release to accelerator pedal apply. The brakes release
when the accelerator pedal is applied. HSA
brake hold duration may be selectable.
Standard Hold automatically releases the
brakes after a few seconds. Extended Hold
applies the Electric Parking Brake if the
accelerator pedal is not applied within a few
minutes. If hold duration is selectable, see
"Extended Hill Start Assist" in
Vehicle
Personalization 0108. The brakes may also
release under other conditions. Do not rely
on HSA to hold the vehicle.
HSA is available when the vehicle is facing
uphill in a forward gear, or when facing
downhill in R (Reverse). The vehicle must
come to a complete stop on a grade for HSA
to activate.
Ride Control Systems
Traction Control/Electronic
Stability Control
System Operation
The vehicle has a Traction Control System
(TCS) and StabiliTrak/Electronic Stability
Control (ESC), an electronic stability control system. These systems help limit wheel slip
and assist the driver in maintaining control,
especially on slippery road conditions.
TCS activates if it senses that any of the
drive wheels are spinning or beginning to
lose traction. When this happens, TCS
applies the brakes to the spinning wheels
and reduces engine power to limit
wheel spin.
StabiliTrak/ESC activates when the vehicle
senses a difference between the intended
path and the direction the vehicle is actually
traveling. StabiliTrak/ESC selectively applies
braking pressure to any one of the vehicle
wheel brakes to assist the driver in keeping
the vehicle on the intended path.
If cruise control is being used and TCS or
StabiliTrak/ESC begins to limit wheel spin,
cruise control will disengage. Cruise control
may be turned back on when road
conditions allow.
Both systems come on automatically when
the vehicle is started and begins to move.
The systems may be heard or felt while
they are operating or while performing
diagnostic checks. This is normal and does
not mean there is a problem with the
vehicle.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 249
Driving Characteristics and
Towing Tips
{Warning
You can lose control when towing a
trailer if the correct equipment is not
used or the vehicle is not driven properly.
For example, if the trailer is too heavy or
the trailer brakes are inadequate for the
load, the vehicle may not stop as
expected. You and others could be
seriously injured. The vehicle may also be
damaged, and the repairs would not be
covered by the vehicle warranty. Pull a
trailer only if all the steps in this section
have been followed. Ask your dealer for
advice and information about towing a
trailer with the vehicle.
Driving with a Trailer
Trailering is different than just driving the
vehicle by itself. Trailering means changes in
handling, acceleration, braking, durability,
and fuel economy. Successful, safe trailering
takes correct equipment, and it has to be
used properly.The following information has many
time-tested, important trailering tips and
safety rules. Many of these are important
for your safety and that of your passengers.
Read this section carefully before pulling a
trailer.
When towing a trailer:
.Become familiar with and follow all state
and local laws that apply to trailer
towing. These requirements vary from
state to state.
.State laws may require the use of
extended side view mirrors. Even if not
required, you should install extended side
view mirrors if your visibility is limited or
restricted while towing.
.Do not tow a trailer during the first
800 km (500 mi) of vehicle use to prevent
damage to the engine, axle, or other
parts.
.It is recommended to perform the first oil
change before heavy towing.
.During the first 800 km (500 mi) of trailer
towing, do not drive over 80 km/h
(50 mph) and do not make starts at full
throttle.
.Vehicles can tow in D (Drive). If the
transmission downshifts too often, a
lower gear may be selected using Manual
Mode See
Manual Mode 0211.
If equipped, the following driver assistance
features should be turned off when towing
a trailer:
.Adaptive Cruise Control (ACC)
.Super Cruise Control
.Lane Keep Assist (LKA)
.Park Assist
.Automatic Parking Assist (APA)
.Reverse Automatic Braking (RAB)
If equipped, the following driver assistance
features should be turned to alert or off
when towing a trailer:
.Automatic Emergency Braking (AEB)
.Intelligent Brake Assist (IBA)
.Front Pedestrian Braking (FPB)
If equipped with Lane Change Alert (LCA),
the LCA detection zones that extend back
from the side of the vehicle do not move
further back when a trailer is towed. Use
caution while changing lanes when towing a
trailer.

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 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
304 Vehicle Care
A rear blowout, particularly on a curve, acts
much like a skid and may require the same
correction as used in a skid. Stop pressing
the accelerator pedal and steer to straighten
the vehicle. It may be very bumpy and
noisy. Gently brake to a stop, well off the
road, if possible.
{Warning
Driving on a flat tire will cause
permanent damage to the tire.
Re-inflating a tire after it has been driven
on while severely underinflated or flat
may cause a blowout and a serious crash.
Never attempt to re-inflate a tire that has
been driven on while severely
underinflated or flat. Have your dealer or
an authorized tire service center repair or
replace the flat tire as soon as possible.
{Warning
Lifting a vehicle and getting under it to
do maintenance or repairs is dangerous
without the appropriate safety equipment
and training. If a jack is provided with
the vehicle, it is designed only for(Continued)
Warning (Continued)
changing a flat tire. If it is used for
anything else, you or others could be
badly injured or killed if the vehicle slips
off the jack. If a jack is provided with the
vehicle, only use it for changing a
flat tire.
If a tire goes flat, avoid further tire and
wheel damage by driving slowly to a level
place, well off the road, if possible. Turn on
the hazard warning flashers. See Hazard
Warning Flashers 0119.
{Warning
Changing a tire can be dangerous. The
vehicle can slip off the jack and roll over
or fall causing injury or death. Find a
level place to change the tire. To help
prevent the vehicle from moving:
1. Set the parking brake firmly.
2. Put an automatic transmission in P (Park) or a manual transmission in
1 (First) or R (Reverse).
3. Turn off the engine and do not restart while the vehicle is raised.
(Continued)
Warning (Continued)
4. Do not allow passengers to remainin the vehicle.
5. Place wheel blocks, if equipped, on both sides of the tire at the opposite
corner of the tire being changed.
This vehicle may come with a jack and spare
tire or a tire sealant and compressor kit. To
use the jacking equipment to change a spare
tire safely, follow the instructions below.
Then see Tire Changing 0310. To use the
tire sealant and compressor kit, see Tire
Sealant and Compressor Kit 0305.
When the vehicle has a flat tire (2), use the
following example as a guide to assist you
in the placement of wheel blocks (1),
if equipped.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/-
Mexico-14420055) - 2021 - CRC - 11/13/20
366 Index
Auto StopStop/Start System . . . . . . . . . . . . . . . . . . . . . 201
Automatic Dimming Mirrors . . . . . . . . . . . . . . . . . . . . . . . 25
Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Emergency Braking (AEB) . . . . . . . . . . . . . . 239
Headlamp System . . . . . . . . . . . . . . . . . . . . . . 118
Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
Transmission Fluid . . . . . . . . . . . . . . . . . . . . . 265
Automatic Transmission Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . . . 211
Avoiding Untrusted Media Devices . . . . . . . .134
B
Battery Exterior Lighting Battery Saver . . . . . . . . 122
Load Management . . . . . . . . . . . . . . . . . . . . . . 121
Power Protection . . . . . . . . . . . . . . . . . . . . . . 122
Battery - North America . . . . . . . . . . . . . 273, 316
Blade Replacement, Wiper . . . . . . . . . . . . . . . 275
Bluetooth Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 155, 156
Bluetooth Audio . . . . . . . . . . . . . . . . . . . . . . . . . 136
Brake Parking, Electric . . . . . . . . . . . . . . . . . . . . . . . . 212
System Warning Light . . . . . . . . . . . . . . . . . . 95
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 Antilock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 Brakes (cont'd)
Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Braking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 Automatic Emergency (AEB) . . . . . . . . . . . 239
Braking System Front Pedestrian (FPB) . . . . . . . . . . . . . . . . . 240
Break-In, New Vehicle . . . . . . . . . . . . . . . . . . . . 199
Bulb Replacement Front Turn Signal Lamps . . . . . . . . . . . . . . . 278
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . 277
Headlamp Aiming . . . . . . . . . . . . . . . . . . . . . . 277
Headlamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
High Intensity Discharge (HID)Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
License Plate Lamps . . . . . . . . . . . . . . . . . . . 279
Taillamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Buying New Tires . . . . . . . . . . . . . . . . . . . . . . . . 300
C
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81
California Perchlorate Materials Requirements . . . 258
California Proposition 65 Warning . . . . . . . . . . . . . . . . . . .258, 273, 316, Back Cover
Canadian Vehicle Owners . . . . . . . . . . . . . . . . . . . 1
Capacities and Specifications . . . . . . . . . . . . . 343 Carbon Monoxide
Engine Exhaust . . . . . . . . . . . . . . . . . . . . . . . . 207
Liftgate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Winter Driving . . . . . . . . . . . . . . . . . . . . . . . . . 194
Cargo Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Tie-Downs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Caution, Danger, and Warning . . . . . . . . . . . . . .2
Center Console Storage . . . . . . . . . . . . . . . . . . . .75
Chains, Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
Charging Wireless . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Charging System Light . . . . . . . . . . . . . . . . . . . . 93
Check Engine Light (Malfunction Indicator) . . . . 93
Child Restraints
Infants and Young Children . . . . . . . . . . . . . 58
Lower Anchors and Tethers forChildren . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Older Children . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Securing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69, 70
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Circuit Breakers . . . . . . . . . . . . . . . . . . . . . . . . . . 280
Cleaning Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
Climate Control Systems . . . . . . . . . . . . . . . . . .178 Air Conditioning . . . . . . . . . . . . . . . . . . . . . . . 178