ignition GMC TERRAIN 2021 Service Manual

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
204 Driving and Operating
5. Plug the other end of the cord into anormal, grounded 110-volt AC outlet.
{Warning
Improper use of the heater cord or an
extension cord can damage the cord and
may result in overheating and fire.
.Plug the cord into a three-prong
electrical utility receptacle that is
protected by a ground fault detection
function. An ungrounded outlet could
cause an electric shock.
.Use a weatherproof, heavy-duty,
15 amp-rated extension cord if needed.
Failure to use the recommended
extension cord in good operating
condition, or using a damaged heater
or extension cord, could make it
overheat and cause a fire, property
damage, electric shock, and injury.
.Do not operate the vehicle with the
heater cord permanently attached to
the vehicle. Possible heater cord and
thermostat damage could occur.
(Continued)
Warning (Continued)
.While in use, do not let the heater
cord touch vehicle parts or sharp
edges. Never close the hood on the
heater cord.
.Before starting the vehicle, unplug the
cord, reattach the cover to the plug,
and securely fasten the cord. Keep the
cord away from any moving parts.
The length of time the heater should remain
plugged in depends on several factors. Ask a
dealer in the area where you will be parking
the vehicle for the best advice on this.
Retained Accessory Power (RAP)
When the ignition is turned from on to off,
the following features (if equipped) will
continue to function for up to 10 minutes,
or until the driver door is opened. These
features will also work when the ignition is
in RUN or ACC/ACCESSORY:
.Infotainment System
.Power Windows (during RAP this
functionality will be lost when any door
is opened)
.Sunroof (during RAP this functionality will
be lost when any door is opened)
.Auxiliary Power Outlet
.Audio System
.OnStar System
Shifting Into Park
{Warning
It can be dangerous to get out of the
vehicle if the vehicle is not in P (Park)
with the parking brake set. The vehicle
can roll. If you have left the engine
running, the vehicle can move suddenly.
You or others could be injured. To be
sure the vehicle will not move, even
when you are on fairly level ground, use
the steps that follow. If you are pulling a
trailer, see Driving Characteristics and
Towing Tips 0249.
To shift into P (Park): 1. Hold the brake pedal down and set the parking brake. See Electric Parking Brake
0 212.
2. Press P (Park).
3. Turn the ignition off.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
206 Driving and Operating
Caution
The manual park release is not intended
to be used for towing. Damage may
result from using the manual park release
in this way. The repairs would not be
covered by the vehicle warranty.
Pulling the manual park release while the
vehicle is on, or turning the ignition on
while the manual park release is pulled, will
result in a Service Transmission message
being displayed.
To place the vehicle in N (Neutral) using the
manual park release: 1. Ensure the vehicle is on level ground and set the parking brake. Release the brake
pedal.
2. Turn the vehicle off.
3. Use a flat-bladed tool to remove the interior trim panel on the center console
to the right of the accelerator pedal.
4. Ensure more than one minute has elapsed since Step 2. Apply the brake
pedal.5. Pull the manual park release lever 90° toits latching position.
6. With the brake pedal released, place the ignition in ACC/ACCESSORY. Then apply
the brake pedal and release the parking
brake.
7. Ensure there are no loose objects in the area that could bump the manual park
release lever.
To return the vehicle to P (Park) using the
manual park release: 1. Bring the vehicle to a complete stop.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 207
2. Rotate the manual park release 90° backto its original position.
3. Apply the parking brake.
4. Confirm that the vehicle is in P (Park) by turning the ignition on or placing the
ignition in ACC/ACCESSORY, then ensure
that the indicator displays P.
5. Install the interior trim panel.
Parking over Things That Burn
{Warning
Things that can burn could touch hot
exhaust parts under the vehicle and
ignite. Do not park over papers, leaves,
dry grass, or other things that can burn.
Extended Parking
It is best not to park with the vehicle
running. If the vehicle is left running, be
sure it will not move and there is adequate
ventilation.
See Shifting Into Park 0204 and
Engine Exhaust 0207.
If the vehicle is left parked and running with
the RKE transmitter outside the vehicle, it
will continue to run for up to 20 minutes.
If the vehicle is left parked and running with
the RKE transmitter inside the vehicle, it will
continue to run for up to 60 minutes.
The vehicle could turn off sooner if it is
parked on a hill, due to lack of
available fuel.
The timer will reset if the vehicle is taken
out of P (Park) while it is running.
Engine Exhaust
{
Warning
Engine exhaust contains carbon monoxide
(CO), which cannot be seen or smelled.
Exposure to CO can cause
unconsciousness and even death.
Exhaust may enter the vehicle if:
.The vehicle idles in areas with poor
ventilation (parking garages, tunnels,
deep snow that may block underbody
airflow or tail pipes).
.The exhaust smells or sounds strange
or different.
.The exhaust system leaks due to
corrosion or damage.
.The vehicle exhaust system has been
modified, damaged, or improperly
repaired.
.There are holes or openings in the
vehicle body from damage or
aftermarket modifications that are not
completely sealed. (Continued)

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
Driving and Operating 213
cannot be applied or released. To prevent
draining the battery, avoid unnecessary
repeated cycles of the EPB.
The system has a red parking brake status
light and an amber service parking brake
warning light. SeeElectric Parking Brake
Light 095 and
Service Electric Parking Brake Light 095.
There are also parking brake-related Driver
Information Center (DIC) messages.
Before leaving the vehicle, check the red
parking brake status light to ensure that the
parking brake is applied.
EPB Apply
To apply the EPB:
1. Be sure the vehicle is at a complete stop.
2. Press the EPB switch momentarily.
The red parking brake status light will flash
and then stay on once the EPB is fully
applied. If the red parking brake status light
flashes continuously, then the EPB is only
partially applied or there is a problem with
the EPB. A DIC message will display. Release
the EPB and try to apply it again. If the
light does not come on, or keeps flashing, have the vehicle serviced. Do not drive the
vehicle if the red parking brake status light
is flashing. See your dealer.
If the amber service parking brake warning
light is on, press the EPB switch. Continue to
hold the switch until the red parking brake
status light remains on. If the amber service
parking brake warning light is on, see your
dealer.
If the EPB is applied while the vehicle is
moving, the vehicle will decelerate as long
as the switch is pressed. If the switch is
pressed until the vehicle comes to a stop,
the EPB will remain applied.
The vehicle may automatically apply the EPB
in some situations when the vehicle is not
moving. This is normal, and is done to
periodically check the correct operation of
the EPB system, or at the request of other
safety functions that utilize the EPB.
If the EPB fails to apply, block the rear
wheels to prevent vehicle movement.
EPB Release
To release the EPB:
1. Turn the ignition on or to ACC/ ACCESSORY.
2. Apply and hold the brake pedal. 3. Press the EPB switch momentarily.
The EPB is released when the red parking
brake status light is off.
If the amber service parking brake warning
light is on, release the EPB by pressing and
holding the EPB switch. Continue to hold the
switch until the red parking brake status
light is off. If either light stays on after
release is attempted, see your dealer.
Caution
Driving with the parking brake on can
overheat the brake system and cause
premature wear or damage to brake
system parts. Make sure that the parking
brake is fully released and the brake
warning light is off before driving.
If you are towing a trailer and parking on a
hill, see Driving Characteristics and Towing
Tips 0249.
Automatic EPB Release
The EPB will automatically release if the
vehicle is running, placed into gear, and an
attempt is made to drive away. Avoid rapid
acceleration when the EPB is applied, to
preserve parking brake lining life.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 219
If the vehicle is in Tour (FWD) or AWD, it
will stay in that mode through future
ignition cycles. If the vehicle is in any other
mode, it will revert back to Tour (FWD)
when the vehicle is restarted.
4AWD Mode :AWD Mode provides drive
torque to all four wheels. Select AWD to
improve traction and control on slippery
road surfaces, such as gravel, sand, wet
pavement, snow, and ice. When selecting
AWD Mode, the AWD light will flash briefly
while the system is engaging and then stay
on to indicate AWD is active. AWD is active
in Tow/Haul and Off-Road Modes. AWD
Mode is only available on vehicles equipped
with AWD.
When using a compact spare tire on an
AWD vehicle, the system automatically
detects the compact spare and reduces AWD
performance to protect the system. To
restore full AWD operation and prevent
excessive wear on the system, replace the
compact spare tire with a full-size tire as
soon as possible. See Compact Spare Tire
0 315.
6Snow Mode : Snow Mode improves
vehicle acceleration on snow and ice-covered
roads. Snow Mode is not available on
vehicles equipped with AWD.
7Off-Road Mode : Use Off-Road Mode for
public off-road recreational driving. See
Off-Road Driving 0190. Off-Road Mode is
only available on vehicles equipped
with AWD.
_Tow/Haul Mode : Tow/Haul Mode can
assist when towing or hauling a heavy load.
It changes transmission shift patterns, turns
on AWD, if equipped, and increases trailer
sway control assistance. See Driving
Characteristics and Towing Tips 0249. Tow/
Haul Mode is only available on vehicles with
the towing package. Automatic Engine Grade Braking
Automatic Engine Grade Braking assists
when driving downhill. It maintains vehicle
speed by automatically implementing a shift
pattern that uses the engine and the
transmission to slow the vehicle. The system
will automatically command downshifts to
reduce vehicle speed. The normal shift
pattern will return once the vehicle is on a
low grade or when the accelerator pedal is
pressed.
While in the Electronic Range Select (ERS)
Mode, grade braking is deactivated, allowing
a range to be selected and limiting the
highest gear available. Grade braking is
available for normal driving and in Tow/Haul
Mode. See
Manual Mode 0211.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
220 Driving and Operating
Mode Name In Cluster Menu:TourAWD Snow Off-Road Tow/Haul
Mode Availability AWD & FWD AWD FWD AWD Towing Package
(AWD & FWD)
Retained Across Ignition Cycles YesYesNoNo No
Pedal Map Normal Normal Off-Road Off-Road Normal
Auto Transmission Schedule Normal Normal Normal Normal Tow/Haul
AWD (If Equipped) Normal FWD Normal AWD NA Off-Road AWD Normal AWD
Steering Normal Normal Normal Normal Tow/Haul
Trailer Sway Control Normal Normal Normal Normal Tow/Haul
StabiliTrak Setting Normal Normal Normal Off-Road Normal
Traction Control Setting Normal Normal Normal Off-Road Normal
Cruise Control
The cruise control lets the vehicle maintain a
speed of about 40 km/h (25 mph) or more
without keeping your foot on the
accelerator. Cruise control does not work at
speeds below 40 km/h (25 mph).
{Warning
Cruise control can be dangerous where
you cannot drive safely at a steady
speed. Do not use cruise control on
winding roads or in heavy traffic.
Cruise control can be dangerous on
slippery roads. On such roads, fast
changes in tire traction can cause
(Continued)
Warning (Continued)
excessive wheel slip, and you could lose
control. Do not use cruise control on
slippery roads.
With the Traction Control System (TCS) or
StabiliTrak/Electronic Stability Control (ESC),
the system may begin to limit wheel spin
while you are using cruise control. If this
happens, the cruise control will

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
222 Driving and Operating
The speedometer reading can be displayed
in either English or metric units.
SeeInstrument Cluster (Base and Midlevel)
0 85 or
Instrument Cluster (Uplevel) 088. The
increment value used depends on the units
displayed.
Reducing Speed While Using Cruise Control
If the cruise control system is already
activated:
.Press and hold –SET until the desired
lower speed is reached, then release it.
.To slow down in small increments, briefly
press –SET. For each press, the vehicle
goes about 1 km/h (1 mph) slower.
The speedometer reading can be displayed
in either English or metric units.
See Instrument Cluster (Base and Midlevel)
0 85 or
Instrument Cluster (Uplevel) 088. The
increment value used depends on the units
displayed.
Passing Another Vehicle While Using Cruise
Control
Use the accelerator pedal to increase the
vehicle speed. When you take your foot off
the pedal, the vehicle will slow down to the
previous set cruise speed. While pressing the accelerator pedal or shortly following the
release to override cruise control, briefly
pressing
–SET will result in cruise control set
to the current vehicle speed.
Using Cruise Control on Hills
How well the cruise control works on hills
depends upon the vehicle speed, load, and
the steepness of the hills. When going up
steep hills, you might have to step on the
accelerator pedal to maintain the vehicle
speed. When going downhill, you might
have to brake or shift to a lower gear to
keep your speed down. If the brake pedal is
applied, cruise control will disengage.
Ending Cruise Control
There are four ways to end cruise control:
.Step lightly on the brake pedal.
.Press*.
.Shift the transmission to N (Neutral).
.To turn off cruise control, press5.
Erasing Speed Memory
The cruise control set speed is erased from
memory if
5is pressed or if the ignition is
turned off.
Adaptive Cruise Control (Camera)
If equipped, Adaptive Cruise Control (ACC)
allows the cruise control set speed and
following gap to be selected. Read this
entire section before using this system. The
following gap is the following time between
your vehicle and a vehicle detected directly
ahead in your path, moving in the same
direction. If no vehicle is detected in your
path, ACC works like regular cruise control.
ACC uses a windshield mounted front
camera sensor.
If a vehicle is detected in your path, ACC can
apply acceleration or limited, moderate
braking to maintain the selected following
gap. To disengage ACC, apply the brake.
If ACC is controlling the vehicle speed when
the Traction Control System (TCS) or
StabiliTrak/Electronic Stability Control (ESC)
system activates, ACC may automatically
disengage. See Traction Control/Electronic
Stability Control 0214. When road
conditions allow ACC to be safely used, ACC
can be turned back on.
Disabling the TCS or StabiliTrak/ESC system
will disengage and prevent engagement
of ACC.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
228 Driving and Operating
.A DIC message displays to indicate that
ACC is temporarily unavailable.
The ACC indicator will turn white when ACC
is no longer active.
In some cases, when ACC is temporarily
unavailable, regular cruise control may be
used. See “Switching Between ACC and
Regular Cruise Control” in this section.
Always consider driving conditions before
using either cruise control system.
Notification to Resume ACC
ACC will maintain a follow gap behind a
detected vehicle and slow your vehicle to a
stop behind that vehicle.
If the stopped vehicle ahead has driven
away and ACC has not resumed, the vehicle
ahead indicator will flash as a reminder to
check traffic ahead before proceeding. In
addition, the left and right sides of the
Safety Alert Seat will pulse three times,
or three beeps will sound. See ”Alert Type”
and “Adaptive Cruise Go Notifier” in
“Collision/Detection Systems” underVehicle
Personalization 0108.
When the vehicle ahead drives away, ACC
resumes automatically if the stop was brief.
If necessary, press RES+ or the accelerator
pedal to resume ACC. If stopped for more than two minutes or if the driver door is
opened and the driver seat belt is
unbuckled, the ACC automatically applies the
Electric Parking Brake (EPB) to hold the
vehicle. The EPB status light will turn on.
See
Electric Parking Brake 0212. To release
the EPB, press the accelerator pedal.
A DIC warning message may display
indicating to shift to P (Park) before exiting
the vehicle. See Vehicle Messages 0108.
{Warning
If ACC has stopped the vehicle, and if ACC
is disengaged, turned off, or canceled, the
vehicle will no longer be held at a stop.
The vehicle can move. When ACC is
holding the vehicle at a stop, always be
prepared to manually apply the brakes.
{Warning
Leaving the vehicle without placing it in
P (Park) can be dangerous. Do not leave
the vehicle while it is being held at a
stop by ACC. Always place the vehicle in
P (Park) and turn off the ignition before
leaving the vehicle. ACC Override
If using the accelerator pedal while ACC is
active, the ACC indicator turns blue on the
instrument cluster, to indicate that
automatic braking will not occur. ACC will
resume operation when the accelerator
pedal is not being pressed.
{Warning
The ACC will not automatically apply the
brakes if your foot is resting on the
accelerator pedal. You could crash into a
vehicle ahead of you.
Curves in the Road
{Warning
On curves, ACC may not detect a vehicle
ahead in your lane. You could be startled
if the vehicle accelerates up to the set
speed, especially when following a vehicle
exiting or entering exit ramps. You could
lose control of the vehicle or crash. Do
not use ACC while driving on an entrance
or exit ramp. Always be ready to use the
brakes if necessary.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
230 Driving and Operating
Do Not Use ACC on Hills and When Towing a
Trailer
Do not use ACC when driving on steep hills
or when towing a trailer. ACC will not detect
a vehicle in the lane while driving on steep
hills. If the brakes are applied, ACC
disengages.
Disengaging ACC
There are three ways to disengage ACC:
.Step lightly on the brake pedal.
.Press*.
.PressJ.
Erasing Speed Memory
The ACC set speed is erased from memory if
Jis pressed or if the ignition is turned off. Weather Conditions Affecting ACC
If the interior temperature is extremely
high, the instrument cluster may indicate
that ACC is temporarily unavailable. This can
be caused by extreme hot weather
conditions with direct sunlight on the front
camera. ACC will return to normal operation
once the cabin temperature is lower.
Conditions that are associated with low
visibility, such as fog, rain, snow, or road
spray, may limit ACC performance. Water
droplets from rain or snow that remain on
the windshield may also limit ACC’s ability
to detect objects.
{Warning
Camera visibility may be limited and the
ACC system may not work properly if the
windshield is not clear. Do not use ACC if
moisture is present on the inside of the
windshield or the windshield washer is
used in cold weather. Turn on the front
defroster and make sure the windshield is
clear before using ACC. Before driving,
check that the windshield wipers are in
good condition and replace them if worn. Lighting Conditions Affecting ACC
The ACC front camera can be affected by
poor lighting conditions, and ACC may have
limited performance when:
.There are changes in brightness, such as
entering and exiting tunnels, bridges, and
overpasses.
.Low sun angles cause the camera to not
detect objects, or it is more difficult to
detect objects in the same traffic lane.
.Lighting is poor in the evening or early
morning
.There are multiple changes in brightness
or shadows along the vehicle roadway.
.In a tunnel without the headlamps on,
or in a tunnel when there is a vehicle in
front that does not have its taillamps on.
.Subjected to strong light from opposing
lane traffic in the front of the vehicle,
such as high-beam headlamps from
oncoming traffic.
Accessory Installations and Vehicle
Modifications
Do not install or place any object around
the front camera windshield area that would
obstruct the front camera view.