reset 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 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 211
D :This position is for normal driving.
If more power is needed for passing, press
the accelerator pedal down.
To shift into D (Drive):
1. Bring the vehicle to a complete stop.
2. Pull the D (Drive) switch on the center stack.
To shift out of D (Drive): 1. Bring the vehicle to a complete stop.
2. Shift to the desired gear.
Downshifting the transmission in slippery
road conditions could result in skidding. See
“Skidding” underLoss of Control 0190.
Caution
Spinning the tires or holding the vehicle
in one place on a hill using only the
accelerator pedal may damage the
transmission. The repair will not be
covered by the vehicle warranty. If the
vehicle is stuck, do not spin the tires.
When stopping on a hill, use the brakes
to hold the vehicle in place.
Manual Mode
Electronic Range Select (ERS) Mode
ERS or manual mode allows for the selection
of the range of gear positions. Use this
mode when driving downhill or towing a
trailer to limit the top gear and vehicle
speed. The shift position indicator within the
Driver Information Center (DIC) will display a
number next to the L indicating the highest
available gear under manual mode and the
driving conditions when manual mode was
selected.
To use this feature:
1. With the vehicle in D (Drive), press the L (Low) button. 2. Press the plus or minus button on the
center stack to increase or decrease the
gear range available.
When shifting to L (Low), the transmission
will shift to a preset lower gear range. For
this preset range, the highest gear available
is displayed next to the L in the DIC. See
Driver Information Center (DIC) (Base and
Midlevel) 0100 or
Driver Information Center (DIC) (Uplevel)
0 105. All gears below that number are
available to use. For example, when
4 (Fourth) is shown next to the L, 1 (First)
through 4 (Fourth) gears are shifted
automatically. To shift to 5 (Fifth) gear, press
the + (Plus) button or shift into D (Drive).
L (Low) will prevent shifting to a lower gear
range if the engine speed is too high.
If vehicle speed is not reduced within the
time allowed, the lower gear range shift will
not be completed. Slow the vehicle, then
press the −(Minus) button to the desired
lower gear range.
While using ERS, cruise control can be used.
Tow/Haul Mode
For information on the Tow/Haul Mode, see
Driver Mode Control 0218.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
264 Vehicle Care
Engine oil system flushes are not
recommended and could cause engine
damage not covered by the vehicle
warranty.
What to Do with Used Oil
Used engine oil contains certain elements
that can be unhealthy for your skin and
could even cause cancer. Do not let used oil
stay on your skin for very long. Clean your
skin and nails with soap and water, or a
good hand cleaner. Wash or properly
dispose of clothing or rags containing used
engine oil. See the manufacturer's warnings
about the use and disposal of oil products.
Used oil can be a threat to the environment.
If you change your own oil, be sure to drain
all the oil from the filter before disposal.
Never dispose of oil by putting it in the
trash or pouring it on the ground, into
sewers, or into streams or bodies of water.
Recycle it by taking it to a place that
collects used oil.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system that
indicates when to change the engine oil and
filter. This is based on a combination offactors which include engine revolutions,
engine temperature, and miles driven. Based
on driving conditions, the mileage at which
an oil change is indicated can vary
considerably. For the oil life system to work
properly, the system must be reset every
time the oil is changed.
When the system has calculated that oil life
has been diminished, it indicates that an oil
change is necessary. A CHANGE ENGINE OIL
SOON message comes on. Change the oil as
soon as possible within the next 1 000 km
(600 mi). It is possible that, if driving under
the best conditions, the oil life system may
indicate that an oil change is not necessary
for up to a year. The engine oil and filter
must be changed at least once a year and,
at this time, the system must be reset. Your
dealer has trained service people who will
perform this work and reset the system.
It is also important to check the oil regularly
over the course of an oil drain interval and
keep it at the proper level.
If the system is ever reset accidentally, the
oil must be changed at 5 000 km (3,000 mi)
since the last oil change. Remember to reset
the oil life system whenever the oil is
changed.
How to Reset the Engine Oil Life System
Reset the system whenever the engine oil is
changed so that the system can calculate
the next engine oil change. To reset the
system:
1. Display REMAINING OIL LIFE on the DIC menu. See Driver Information Center
(DIC) (Base and Midlevel) 0100 or
Driver Information Center (DIC) (Uplevel)
0 105.
2. Press and hold
Vfor several seconds
while the Oil Life display is active to
reset the Oil Life system.
3. REMAINING OIL LIFE 100% will be displayed when the oil life system is
successfully reset.
The oil life system can also be reset as
follows: 1. Place the ignition in Service Mode. See Ignition Positions 0199.
2. Display REMAINING OIL LIFE on the DIC menu. See Driver Information Center
(DIC) (Base and Midlevel) 0100 or
Driver Information Center (DIC) (Uplevel)
0 105.
3. Fully press and release the accelerator pedal three times within five seconds.

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 267
5. Verify that the wiring harness connectoris fully connected to the sensor on the
air cleaner/filter housing.
6. If equipped, reset the engine air filter life system after replacing the engine air
filter, see Engine Air Filter Life System
0 265.
{Warning
Operating the engine with the air
cleaner/filter off can cause you or others
to be burned. Use caution when working
on the engine. Do not start the engine or
drive the vehicle with the air cleaner/
filter off, as flames may be present if the
engine backfires.
Caution
If the air cleaner/filter is off, dirt can
easily get into the engine, which could
damage it. Always have the air cleaner/
filter in place when driving.
Cooling System
1. Engine Cooling Fan (Out of View)
2. Engine Coolant Surge Tank and
Pressure Cap
{Warning
An underhood electric fan can start up
even when the engine is not running and
can cause injury. Keep hands, clothing,
and tools away from any underhood
electric fan.
{Warning
Do not touch heater or radiator hoses,
or other engine parts. They can be very
hot and can burn you. Do not run the
engine if there is a leak; all coolant could
leak out. That could cause an engine fire
and can burn you. Fix any leak before
driving the vehicle.
If the coolant inside the coolant surge tank
is boiling, do not do anything else until it
cools down. The vehicle should be parked on
a level surface.
The coolant level should be at the top rib on
the middle of the tank. If it is not, the
vehicle may have a leak at the radiator
hoses, heater hoses, radiator, water pump,
or somewhere else in the cooling system.
If there seems to be no leak, with the
engine on, check to see if the electric engine
cooling fan is running. If the engine is
overheating, the fan should be running. If it
is not, the vehicle needs service. Turn off
the engine.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Vehicle Care 277
Trunk
Liftgate
Headlamp Aiming
Front Headlamp Aiming
Headlamp aim has been preset and should
need no further adjustment.
If the vehicle is damaged in a crash, the
headlamp aim may be affected.
If adjustment to the headlamps is necessary,
see your dealer.
Bulb Replacement
For the proper type of replacement bulbs,
or any bulb changing procedure not listed in
this section, contact your dealer.
Caution
Do not replace incandescent bulbs with
aftermarket LED replacement bulbs. This
can cause damage to the vehicle electrical
system.
Halogen Bulbs
{Warning
Halogen bulbs have pressurized gas inside
and can burst if you drop or scratch the
bulb. You or others could be injured. Be
sure to read and follow the instructions
on the bulb package.
High Intensity Discharge (HID)
Lighting
{Warning
The High Intensity Discharge (HID)
lighting system operates at a very high
voltage. If you try to service any of the
system components, you could be
seriously injured. Have your dealer or a
qualified technician service them.
After an HID headlamp bulb has been
replaced, the beam might be a slightly
different shade than it was originally. This is
normal.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
298 Vehicle Care
9. Proceed to the passenger side rear tire,and repeat the procedure in Step 7.
10. Proceed to the driver side rear tire, and repeat the procedure in Step 7. The horn
sounds two times to indicate the sensor
identification code has been matched to
the driver side rear tire, and the TPMS
sensor matching process is no longer
active. The TIRE LEARNING ACTIVE
message on the DIC display goes off.
11. Turn the vehicle off.
12. Set all four tires to the recommended air pressure level as indicated on the Tire
and Loading Information label.
Tire Inspection
We recommend that the tires, including
the spare tire, if the vehicle has one, be
inspected for signs of wear or damage
at least once a month.
Replace the tire if:
.The indicators at three or more
places around the tire can be seen.
.There is cord or fabric showing
through the tire's rubber.
.The tread or sidewall is cracked, cut,
or snagged deep enough to show
cord or fabric.
.The tire has a bump, bulge, or split.
.The tire has a puncture, cut, or other
damage that cannot be repaired well
because of the size or location of the
damage.
Tire Rotation
Tires should be rotated every 12 000 km
(7,500 mi). See Maintenance Schedule
0 331.
Tires are rotated to achieve a more
uniform wear for all tires. The first
rotation is the most important.
Anytime unusual wear is noticed, rotate
the tires as soon as possible, check for
proper tire inflation pressure, and check
for damaged tires or wheels. If the
unusual wear continues after the
rotation, check the wheel alignment.
See When It Is Time for New Tires
0 299 and
Wheel Replacement 0302.
Use this rotation pattern when rotating
the tires.
Do not include the compact spare tire
in the tire rotation.
Adjust the front and rear tires to the
recommended inflation pressure on the
Tire and Loading Information label after
the tires have been rotated. See Tire
Pressure 0293 and
Vehicle Load Limits 0196.
Reset the Tire Pressure Monitor System.
See Tire Pressure Monitor Operation
0 295.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Service and Maintenance 331
Because of the way people use vehicles,
maintenance needs vary. There may need to
be more frequent checks and services. The
Additional Required Services - Normal are for
vehicles that:
.Carry passengers and cargo within
recommended limits on the Tire and
Loading Information label. SeeVehicle
Load Limits 0196.
.Are driven on reasonable road surfaces
within legal driving limits.
.Use the recommended fuel. See
Recommended Fuel (LYX - 1.5L L4 Turbo
Engine) 0246.
Refer to the information in the Maintenance
Schedule Additional Required Services -
Normal chart.
The Additional Required Services - Severe are
for vehicles that are:
.Mainly driven in heavy city traffic in hot
weather.
.Mainly driven in hilly or mountainous
terrain.
.Frequently towing a trailer.
.Used for high speed or competitive
driving.
.Used for taxi, police, or delivery service. Refer to the information in the Maintenance
Schedule Additional Required Services -
Severe chart.
{Warning
Performing maintenance work can be
dangerous and can cause serious injury.
Perform maintenance work only if the
required information, proper tools, and
equipment are available. If they are not,
see your dealer to have a trained
technician do the work. See
Doing Your
Own Service Work 0259.
Maintenance Schedule
Owner Checks and Services
Check the engine oil level. See Engine Oil
0 262.
Once a Month
.Check the tire inflation pressures. See Tire
Pressure 0293.
.Inspect the tires for wear. See Tire
Inspection 0298.
.Check the windshield washer fluid level.
See Washer Fluid 0271.
Engine Oil Change
When the CHANGE ENGINE OIL SOON
message displays, have the engine oil and
filter changed within the next 1 000 km/
600 mi. If driven under the best conditions,
the engine oil life system may not indicate
the need for vehicle service for up to a year.
The engine oil and filter must be changed at
least once a year and the oil life system
must be reset. Your trained dealer technician
can perform this work. If the engine oil life
system is reset accidentally, service the
vehicle within 5 000 km/3,000 mi since the
last service. Reset the oil life system when
the oil is changed. See Engine Oil Life
System 0264.
Air Conditioning Desiccant (Replace Every
Seven Years)
The air conditioning system requires
maintenance every seven years. This service
requires replacement of the desiccant to
help the longevity and efficient operation of
the air conditioning system. This service can
be complex. See your dealer.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
332 Service and Maintenance
Tire Rotation and Required Services
Every 12 000 km/7,500 mi
Rotate the tires, if recommended for the
vehicle, and perform the following services.
SeeTire Rotation 0298.
.Check engine oil level and oil
life percentage. If needed, change engine
oil and filter, and reset oil life system.
See Engine Oil 0262 and
Engine Oil Life System 0264.
.If equipped with the engine air filter life
system, check the air filter
life percentage. If necessary, replace the
engine air filter and reset the engine air
filter life system. See Engine Air Filter Life
System 0265. If the vehicle is not
equipped with the engine air filter life
system, inspect the engine air cleaner
filter. See Engine Air Cleaner/Filter 0265.
.Check engine coolant level. See Cooling
System 0267.
.Check windshield washer fluid level. See
Washer Fluid 0271.
.Check tire inflation pressures. See Tire
Pressure 0293.
.Inspect tire wear. See Tire Inspection
0 298.
.Visually check for fluid leaks.
.Inspect engine air cleaner filter. See
Engine Air Cleaner/Filter 0265.
.Inspect brake system. See Exterior Care
0 322.
.Visually inspect steering, suspension, and
chassis components for damage, including
cracks or tears in the rubber boots, loose
or missing parts, or signs of wear at least
once a year. See Exterior Care0322.
.Inspect power steering for proper
attachment, connections, binding, leaks,
cracks, chafing, etc.
.Visually inspect halfshafts and drive
shafts for excessive wear, lubricant leaks,
and/or damage including: tube dents or
cracks, constant velocity joint or universal
joint looseness, cracked or missing boots,
loose or missing boot clamps, center
bearing excessive looseness, loose or
missing fasteners, and axle seal leaks.
.Check restraint system components. See
Safety System Check 046.
.Visually inspect fuel system for damage
or leaks.
.Visually inspect exhaust system and
nearby heat shields for loose or damaged
parts.
.Lubricate body components. See Exterior
Care 0322.
.Check starter switch. See Starter Switch
Check 0274.
.Check parking brake and automatic
transmission park mechanism. See Park
Brake and P (Park) Mechanism Check
0 274.
.Check accelerator pedal for damage, high
effort, or binding. Replace if needed.
.Visually inspect gas strut for signs of
wear, cracks, or other damage. Check the
hold open ability of the strut. If the hold
open ability is low, service the gas strut.
See Gas Strut(s) 0276.
.Check tire sealant expiration date,
if equipped. See Tire Sealant and
Compressor Kit 0305.
.Inspect sunroof track and seal,
if equipped. See Sunroof027.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
344 Technical Data
ApplicationCapacities
Metric English
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this manual. Recheck fluid level
after filling.
*Engine cooling system capacity values are based on the entire cooling system and its components.
Engine Specifications
Engine VIN CodeTransmission Spark Plug Gap
1.5L L4 Gas Engine (LYX) VAutomatic0.60–0.70 mm (0.024–0.028 in)
Spark plug gaps are preset by the manufacturer. Re-gapping the spark plug is not recommended and can damage the spark plug.