2020 GMC TERRAIN warning

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
262 Driving and Operating
Trailer Towing
General Towing
Information
Only use towing equipment that has
been designed for the vehicle.
Contact your dealer or trailering
dealer for assistance with preparing
the vehicle to tow a trailer. Read the
entire section before towing a trailer.
To tow a disabled vehicle, see
Towing the Vehicle0352. To tow
the vehicle behind another vehicle
such as a motor home, see
Recreational Vehicle Towing 0353.
When towing with the 2.0L L4
engine, only use unleaded gasoline
with an octane rating of 89 or
higher. Using gasoline with a lower
octane rating while towing may
damage the engine and may not be
covered by the vehicle warranty.
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.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
Driving and Operating 263
.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 0205.
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.
If equipped with Rear Cross Traffic
Alert (RCTA), use caution while
backing up when towing a trailer, as
the RCTA detection zones that
extend out from the back of the
vehicle do not move further back
when a trailer is towed.{Warning
To prevent serious injury or death
from carbon monoxide (CO),
when towing a trailer: . Do not drive with the
liftgate, trunk/hatch,
or rear-most window open.
. Fully open the air outlets on
or under the instrument
panel.
. Adjust the climate control
system to a setting that
brings in only outside air.
See “Climate Control
Systems” in the Index.
For more information about
carbon monoxide, see Engine
Exhaust 0191.
Towing a trailer requires experience.
The combination of the vehicle and
trailer is longer and not as
responsive as the vehicle itself. Get
used to the handling and braking of

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
Driving and Operating 265
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, see
Engine Overheating0294.
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 0368. 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
0 294.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
266 Driving and Operating
Trailer Towing
Caution
Towing a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To tow a trailer
correctly, follow the directions in
this section and see your dealer
for important information about
towing a trailer with the vehicle.
Trailer Weight
{Warning
Never exceed the towing capacity
for your vehicle.
Safe trailering requires monitoring
the weight, speed, altitude, road
grades, outside temperature,
dimensions of the front of the trailer,
and how frequently the vehicle is
used to tow a trailer.
Trailer Weight Ratings
When towing a trailer, the combined
weight of the vehicle, vehicle
contents, trailer, and trailer contents
must be below all of the maximum
weight ratings for the vehicle,
including:
. GCWR: Gross Combined Weight
Rating
. GVWR: Gross Vehicle Weight
Rating
. Maximum Trailer Weight Rating
. Maximum Trailer Tongue Weight
Rating
See “Trailer Brakes” underTowing
Equipment 0269 to determine if
brakes are required based on your
trailer's weight.
The only way to be sure the weight
is not exceeding any of these
ratings is to weigh the tow vehicle
and trailer combination, fully loaded
for the trip, getting individual
weights for each of these items.{Warning
You and others could be seriously
injured or killed if the trailer is too
heavy or the trailer brakes are
inadequate for the load. The
vehicle may be damaged, and the
repairs would not be covered by
the vehicle warranty.
Only tow a trailer if all the steps in
this section have been followed.
Ask your dealer for advice and
information about towing a trailer.
Gross Combined Weight
Rating (GCWR)
GCWR is the total allowable weight
of the completely loaded vehicle
and trailer including any fuel,
passengers, cargo, equipment, and
accessories. Do not exceed the
GCWR for your vehicle. The GCWR
for the vehicle is on the Tow Rating
Chart following.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
Driving and Operating 271
Trailer Lamps
Always check all trailer lamps are
working at the beginning of each
trip, and periodically on longer trips.
Turn Signals When Towing a
Trailer
When properly connected, the trailer
turn signals will illuminate to indicate
the vehicle is turning, changing
lanes, or stopping. When towing a
trailer, the arrows on the instrument
cluster will illuminate even if the
trailer is not properly connected or
the bulbs are burned out.
Trailer Tires
Special Trailer (ST) tires differ from
vehicle tires. Trailer tires are
designed with stiff sidewalls to help
prevent sway and to support heavy
loads. These features can make it
difficult to determine if the trailer tire
pressures are low only based on a
visual inspection.Always check all trailer tire
pressures before each trip when the
tires are cool. Low trailer tire
pressure is a leading cause of trailer
tire blow-outs.
Trailer tires deteriorate over time.
The trailer tire sidewall will show the
week and year the tire was
manufactured. Many trailer tire
manufacturers recommend
replacing tires more than six
years old.
Overloading is another leading
cause of trailer tire blow-outs. Never
load your trailer with more weight
than the tires are designed to
support. The load rating is located
on the trailer tire sidewall.
Always know the maximum speed
rating for the trailer tires before
driving. This may be significantly
lower than the vehicle tire speed
rating. The speed rating may be on
the trailer tire sidewall. If the speed
rating is not shown, the default
trailer tire speed rating is 105 km/h
(65 mph).
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. See
Malfunction Indicator
Lamp (Check Engine Light) 0115.
A device connected to the DLC —
such as an aftermarket fleet or
driver-behavior tracking device —
may interfere with vehicle
systems. This could affect vehicle
operation and cause a crash.
Such devices may also access
information stored in the vehicle’s
systems.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/5/19
Vehicle Care 273
Vehicle Care
General Information
General Information . . . . . . . . . . 274
California Proposition65 Warning . . . . . . . . . . . . . . . . . 274
California Perchlorate Materials Requirements . . . . . 275
Accessories and Modifications . . . . . . . . . . . . . . . . 275
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 275
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 276
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 278
Engine Oil . . . . . . . . . . . . . . . . . . . . 283
Engine Oil Life System . . . . . . . 287
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 288
Engine Air Cleaner/Filter . . . . . . 288
Cooling System . . . . . . . . . . . . . . 290
Engine Overheating . . . . . . . . . . 294
Washer Fluid . . . . . . . . . . . . . . . . . 296
Brakes . . . . . . . . . . . . . . . . . . . . . . . 296
Brake Fluid . . . . . . . . . . . . . . . . . . . 297
Battery - North America . . . . . . 298
All-Wheel Drive . . . . . . . . . . . . . . . 299 Starter Switch Check . . . . . . . . . 299
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . 300
Wiper Blade Replacement . . . . 300
Windshield Replacement . . . . . 301
Gas Strut(s) . . . . . . . . . . . . . . . . . . 302
Headlamp Aiming
Front Headlamp Aiming . . . . . . 303
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 303
Halogen Bulbs . . . . . . . . . . . . . . . . 303
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 304
LED Lighting . . . . . . . . . . . . . . . . . 304
Front Turn Signal Lamps . . . . . 304
Taillamps . . . . . . . . . . . . . . . . . . . . . 304
License Plate Lamp . . . . . . . . . . 305
Electrical System
Electrical System Overload . . . 306
Fuses and Circuit Breakers . . . 307
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 307
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 310
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 312
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 314
All-Season Tires . . . . . . . . . . . . . . 315
Winter Tires . . . . . . . . . . . . . . . . . . 315
Summer Tires . . . . . . . . . . . . . . . . 316
Tire Sidewall Labeling . . . . . . . . 316
Tire Designations . . . . . . . . . . . . . 318
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 319
Tire Pressure . . . . . . . . . . . . . . . . . 321
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . . . . 323
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . 324
Tire Inspection . . . . . . . . . . . . . . . . 328
Tire Rotation . . . . . . . . . . . . . . . . . 328
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . 329
Buying New Tires . . . . . . . . . . . . . 330
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . 331
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . . . 332
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . 333
Wheel Replacement . . . . . . . . . . 333
Tire Chains . . . . . . . . . . . . . . . . . . . 334
If a Tire Goes Flat . . . . . . . . . . . . 335
Tire Sealant and Compressor Kit . . . . . . . . . . . . . 336

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/5/19
274 Vehicle Care
Storing the Tire Sealant andCompressor Kit . . . . . . . . . . . . . 342
Tire Changing . . . . . . . . . . . . . . . . 343
Compact Spare Tire . . . . . . . . . . 348
Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . 349
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . 352
Recreational VehicleTowing . . . . . . . . . . . . . . . . . . . . . . 353
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . 356
Interior Care . . . . . . . . . . . . . . . . . . 361
Floor Mats . . . . . . . . . . . . . . . . . . . . 364
General Information
For service and parts needs, visit
your dealer. You will receive
genuine GM parts and GM-trained
and supported service people.
Genuine GM parts have one of
these marks:
California Proposition
65 Warning
{Warning
Most motor vehicles, including
this one, as well as many of its
service parts and fluids, contain
and/or emit chemicals known to
the State of California to cause
cancer and birth defects or other
reproductive harm. Engine
exhaust, many parts and
systems, many fluids, and some
component wear by-products
contain and/or emit these
chemicals. For more information
go to www.P65Warnings.ca.gov/
passenger-vehicle.
See Battery - North America 0298
and
Jump Starting - North America
0 349 and the back cover.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/5/19
Vehicle Care 275
California Perchlorate
Materials Requirements
Certain types of automotive
applications, such as airbag
initiators, seat belt pretensioners,
and lithium batteries contained in
electronic keys, may contain
perchlorate materials. Perchlorate
Material–special handling may
apply. See www.dtsc.ca.gov/
hazardouswaste/perchlorate.
Accessories and
Modifications
Adding non-dealer accessories or
making modifications to the vehicle
can affect vehicle performance and
safety, including such things as
airbags, braking, stability, ride and
handling, emissions systems,
aerodynamics, durability, and
electronic systems like antilock
brakes, traction control, and stability
control. These accessories or
modifications could even cause
malfunction or damage not covered
by the vehicle warranty. Damage to suspension components
caused by modifying vehicle height
outside of factory settings will not be
covered by the vehicle warranty.
Damage to vehicle components
resulting from modifications or the
installation or use of non-GM
certified parts, including control
module or software modifications, is
not covered under the terms of the
vehicle warranty and may affect
remaining warranty coverage for
affected parts.
GM Accessories are designed to
complement and function with other
systems on the vehicle. See your
dealer to accessorize the vehicle
using genuine GM Accessories
installed by a dealer technician.
Also, see
Adding Equipment to the
Airbag-Equipped Vehicle 069.
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
0 394.
This vehicle has an airbag system.
Before attempting to do your own
service work, see Servicing the
Airbag-Equipped Vehicle 068.