service GMC TERRAIN 2020 Workshop Manual

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
252 Driving and Operating
Caution
Do not use blends containing
more than 20% biodiesel. Any
engine, fuel system, or exhaust
after-treatment system damage
would not be covered by the
vehicle warranty.
As a renewable fuel, biodiesel
provides some environmental
benefits. However, biodiesel has
unique properties and needs to be
handled differently than diesel fuel.
Its use presents additional risks and
may not be appropriate in all
situations. Certain vehicle operating
modes increase these risks and
should be avoided.
Biodiesel fuel quality degrades with
time and exposure to high
temperature quicker than Ultra Low
Sulfur Diesel fuel. More frequent
refueling provides the best
opportunity to have a supply of fresh
fuel. Storage at hot ambient
temperatures will accelerate
biodiesel degradation. If the vehicle is not driven often and
uses little fuel, or if it is stored for
extended periods of time, avoid the
use of biodiesel blended fuels
above 5% by volume. When the
vehicle is stored for longer than one
month, it should be run out of
biodiesel to below one-quarter tank,
refueled with biodiesel-free fuel, and
driven several kilometers (miles)
before storage.
Cold Weather Operation
(Diesel)
In cold weather, the fuel filter may
become clogged by wax naturally
present in the fuel. To unclog it,
move the vehicle to a warm garage
area and allow the filter to warm up.
The fuel filter may need to be
replaced. See
Fuel Filter
Replacement (Diesel) 0256.
At temperatures below 0 °C (32 °F),
it is recommended to avoid using
biodiesel blends above 5% blend.
This blend may cause fuel filter
plugging, system gelling, and
freezing that may affect vehicle
starting. You may need to turn the ignition on and off a few times
before the vehicle will start. Also,
idle the vehicle for a couple of
minutes before accelerating.
It is recommended to use Ultra Low
Sulfur No. 1-D diesel fuel or a blend
of No. 1-D and No. 2-D diesel fuel to
enhance vehicle operation in cold
weather at temperatures below 0 °C
(32 °F). Use of No. 1-D diesel fuel
may lower the fuel economy. For
additional information for better cold
weather operation, see
Engine
Heater 0186.Water in Fuel (Diesel)
Improper fuel tank inspection or
cleaning, or contaminated fuel from
suppliers, can cause water to be
pumped into the fuel tank along with
the diesel fuel. If a WATER IN FUEL
- CONTACT SERVICE message
displays, the water must be drained
immediately.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
Driving and Operating 253
{Warning
Diesel fuel containing water is still
combustible. You or others could
be burned. If the fuel needs to be
drained, keep sparks, flames, and
smoking materials away from the
mixture.
Caution
Water in the diesel fuel can
corrode internal components of
the fuel system and lead to
severe damage. It can also
support fungus or bacteria
growth, which can damage the
fuel system and Fuel Operated
Heater (FOH), if equipped. Even
with a diesel fuel biocide, the fuel
system may still need to be
cleaned. Your dealer can advise
of the appropriate solution.(Continued)
Caution (Continued)
If the fuel tank needs to be
purged to remove water, see your
dealer or a qualified technician.
Improper purging can damage the
fuel system and block the FOH.
As an added precaution, drain the
diesel fuel filter of residual water at
every engine oil change. If the
WATER IN FUEL - CONTACT
SERVICE message comes on
frequently, even after draining water
from the fuel filter, see your dealer. Water in Fuel Troubleshooting
If the WATER IN FUEL - CONTACT
SERVICE message comes on:
Problem Recommended
Action
Message
displays but
goes off during
the ignition
cycle. The fuel filter is
partially filled
with water. Drain
the water as
soon as
possible. See
"Removing
Water from the
Fuel Filter"
following.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
Driving and Operating 255
FWD Shown, AWD Similar
3. Turn the drain plug counterclockwise using a
suitable tool.
4. With the engine off, press and hold ENGINE START/STOP
without applying the brake for
five seconds to place the
vehicle in Service Mode. See
Ignition Positions 0179. Wait
approximately five seconds,
and then press ENGINE
START/STOP again to turn it
off. This operation will enhance
water flow out of the filter. The filter is drained as soon as
diesel fuel emerges from
the port.
5. Retighten the drain plug by turning it clockwise.
6. Properly dispose of the water contaminated fuel.
7. Start the engine and let it run for a few minutes. During the
draining process, air may have
entered the fuel system. If the
engine stalls, the fuel system
may need to be primed. See
“Fuel Priming” following.
Fuel Priming
For the fuel system to work properly,
air cannot be in the fuel lines. If air
gets in, the engine may not start
and the fuel lines will need to be
primed before operating the vehicle.
If air is present, the following may
have happened:
. The vehicle ran out of fuel.
. The fuel filter was removed.
. The fuel lines were removed or
disconnected. .
The fuel filter water drain valve
was opened while the engine
was running.
To prime the fuel lines: 1. With the engine off, press and hold ENGINE START/STOP
without applying the brake for
five seconds to place the
vehicle in Service Mode. See
Ignition Positions 0179. Wait
approximately five seconds
and press ENGINE START/
STOP again to turn it off. Do
this step three times or more
while the engine is off.
2. Press and hold ENGINE START/STOP while applying
the brake for a maximum of
40 seconds at a time, with
five seconds between attempts,
until the engine starts. If the
engine tries to run, but does
not run smoothly, increase the
rpm’s slightly by using the
accelerator pedal. This will help
force air through the system.
3. Repeat Step 2 if the engine stalls and will not restart.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/4/19
260 Driving and Operating
{Warning
Overfilling the fuel tank by more
than three clicks of a standard fill
nozzle may cause:. Vehicle performance issues,
including engine stalling and
damage to the fuel system.
. Fuel spills.
. Under certain conditions,
fuel fires.
Diesel fuel can foam when filling the
tank. The automatic pump nozzle
may shut off, even if the tank is not
full. Wait for the foaming to stop,
and then fill the tank more slowly.
Be careful not to spill fuel. Wait
five seconds after pumping before
removing the fill nozzle. Clean fuel
from painted surfaces as soon as
possible. See Exterior Care0356.
Reinstall the cap by turning it
clockwise until it clicks. Push the
fuel door closed until it latches.
{Warning
If a fire starts while you are
refueling, do not remove the fill
nozzle. Shut off the flow of fuel by
shutting off the pump or by
notifying the station attendant.
Leave the area immediately.
Caution
If a new fuel cap is needed, be
sure to get the right type of cap
from your dealer. The wrong type
of fuel cap may not fit properly
and could damage the fuel
system. Accidental Refueling with
Gasoline
Caution
If the vehicle is accidentally
refueled with gasoline, do not
continue driving the vehicle
except to get to a location where
it can be stopped safely. Driving
the vehicle will damage the
engine. Tow the vehicle for
service. Have the gasoline
removed from the tank and fuel
system.
Filling a Portable Fuel
Container (Gasoline)
{Warning
Never fill a portable fuel container
while it is in the vehicle. Static
electricity discharge from the
container can ignite the fuel
vapor. You or others could be
(Continued)

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
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.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13556230) - 2020 - CRC - 9/5/19
276 Vehicle Care
If equipped with remote vehicle
start, open the hood before
performing any service work to
prevent remote starting the vehicle
accidentally. SeeRemote Vehicle
Start 015.
Keep a record with all parts receipts
and list the mileage and the date of
any service work performed. See
Maintenance Records 0380.
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. To open the hood:
1. Pull the hood release lever with the
isymbol. It is on the
lower left side of the instrument
panel.
2. Go to the front of the vehicle and locate the secondary
release lever under the front
center of the hood. Push the
secondary hood release lever
to the right to release.