2019 GMC TERRAIN service

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-12146071) - 2019 - crc - 7/27/18
Driving and Operating 261
Using unleaded gasoline rated
below 93 octane, however, will lead
to reduced acceleration and fuel
economy. If knocking occurs, use a
gasoline rated at 93 octane as soon
as possible, otherwise, the engine
could be damaged. If heavy
knocking is heard when using
gasoline with a 93 octane rating, the
engine needs service.
Prohibited Fuels
(Gasoline)
Caution
Do not use fuels with any of the
following conditions; doing so
may damage the vehicle and void
its warranty:. For vehicles that are not
FlexFuel, fuel labeled
greater than 15% ethanol by
volume, such as mid-level
ethanol blends (16–50%
ethanol), E85, or FlexFuel.
(Continued)
Caution (Continued)
.Fuel with any amount of
methanol, methylal,
ferrocene, and aniline.
These fuels can corrode
metal fuel system parts or
damage plastic and rubber
parts.
. Fuel containing metals such
as methylcyclopentadienyl
manganese tricarbonyl
(MMT), which can damage
the emissions control
system and spark plugs.
. Fuel with a posted octane
rating of less than the
recommended fuel. Using
this fuel will lower fuel
economy and performance,
and may decrease the life of
the emissions catalyst.
Fuels in Foreign
Countries
The U.S., Canada, and Mexico post
fuel octane ratings in anti-knock
index (AKI). For fuel not to use in a
foreign country, see Prohibited
Fuels (Gasoline) 0261.
Fuel Additives (Gasoline)
TOP TIER Detergent Gasoline is
highly recommended for use with
your vehicle. If your country does
not have TOP TIER Detergent
Gasoline, add ACDelco Fuel
System Treatment Plus−Gasoline to
the vehicle’ s gasoline fuel tank at
every oil change or 15,000 km
(9,000 mi), whichever occurs first.
TOP TIER Detergent Gasoline and
ACDelco Fuel System Treatment
Plus−Gasoline will help keep your
vehicle’s engine fuel deposit free
and performing optimally.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-12146071) - 2019 - crc - 7/27/18
264 Driving and Operating
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) 0268.
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 0200.
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.
{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.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-12146071) - 2019 - crc - 7/27/18
Driving and Operating 265
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.
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. Problem
Recommended
Action
Message
displays and
stays on. Drain the fuel
filter
immediately.
If no water can
be drained, and
the temperature
is below
freezing, then
water may be
frozen in the
filter. Move the
vehicle to a
warm location to
thaw the water,
then drain the
fuel. If water still
does not drain,
see your dealer.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-12146071) - 2019 - crc - 7/27/18
266 Driving and Operating
ProblemRecommended
Action
Immediately
after refueling,
message
displays and
stays on. A large amount
of water is in the
fuel tank. Drain
the fuel filter
immediately.
If the message
stays on or
comes back on
without
refueling, then
fuel tank purging
is required. See
your dealer.
If the message
displays and the
engine stalls or
runs rough, do
not drive until
the water
contaminated
fuel is drained.Caution
Driving with this message on can
damage the fuel injection system
and the engine. If the message
comes on right after a refuel,
water was pumped into the fuel
tank. Turn off the engine and
drain the water immediately.
Removing Water from the Fuel
Filter
To drain water: 1. Turn the engine off and apply the parking brake.
2. Place a container under the filter drain valve, which is on
the bottom of the fuel filter.
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 0195. 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

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-12146071) - 2019 - crc - 7/27/18
Driving and Operating 267
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 0195. 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. 4. After a few attempts, if the
engine still does not start, see
your dealer.
Running Out of Fuel
(Diesel)
{Warning
Diesel fuel is flammable. It could
start a fire if something ignites it,
and people could be burned. Do
not let it get on hot engine parts,
and keep matches or other
ignition sources away.
If the engine has stalled due to
running out of fuel, add at least
7.6 L (2 gal) of fuel if parked on a
level surface, or up to 18.9 L (5 gal)
of fuel if parked on a slope, and
perform the procedure under “Fuel
Priming” previously in this section.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-12146071) - 2019 - crc - 7/27/18
Driving and Operating 277
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 0378. 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
0 305.
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.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-12146071) - 2019 - crc - 7/27/18
282 Driving and Operating
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)
0133.
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-12146071) - 2019 - crc - 7/27/18
284 Vehicle Care
Vehicle Care
General Information
General Information . . . . . . . . . . 285
California Proposition65 Warning . . . . . . . . . . . . . . . . . 285
California Perchlorate Materials Requirements . . . . . 286
Accessories and Modifications . . . . . . . . . . . . . . . . 286
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 286
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 287
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 289
Engine Oil . . . . . . . . . . . . . . . . . . . . 294
Engine Oil Life System . . . . . . . 298
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 299
Engine Air Cleaner/Filter . . . . . . 299
Cooling System . . . . . . . . . . . . . . 301
Engine Overheating . . . . . . . . . . 305
Washer Fluid . . . . . . . . . . . . . . . . . 307
Brakes . . . . . . . . . . . . . . . . . . . . . . . 307
Brake Fluid . . . . . . . . . . . . . . . . . . . 308
Battery - North America . . . . . . 309
All-Wheel Drive . . . . . . . . . . . . . . . 310 Starter Switch Check . . . . . . . . . 310
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . 311
Wiper Blade Replacement . . . . 311
Windshield Replacement . . . . . 313
Gas Strut(s) . . . . . . . . . . . . . . . . . . 313
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 314
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 314
Halogen Bulbs . . . . . . . . . . . . . . . . 314
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 315
LED Lighting . . . . . . . . . . . . . . . . . 315
Front Turn Signal Lamps . . . . . 315
Taillamps . . . . . . . . . . . . . . . . . . . . . 316
License Plate Lamp . . . . . . . . . . 316
Electrical System
Electrical System Overload . . . 317
Fuses and Circuit Breakers . . . 318
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 318
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 321
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 323
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 325
All-Season Tires . . . . . . . . . . . . . . 326
Winter Tires . . . . . . . . . . . . . . . . . . 326
Summer Tires . . . . . . . . . . . . . . . . 327
Tire Sidewall Labeling . . . . . . . . 327
Tire Designations . . . . . . . . . . . . . 329
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 330
Tire Pressure . . . . . . . . . . . . . . . . . 332
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . . . . 334
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . 335
Tire Inspection . . . . . . . . . . . . . . . . 339
Tire Rotation . . . . . . . . . . . . . . . . . 339
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . 340
Buying New Tires . . . . . . . . . . . . . 341
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . 342
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . . . 342
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . 344
Wheel Replacement . . . . . . . . . . 344
Tire Chains . . . . . . . . . . . . . . . . . . . 345
If a Tire Goes Flat . . . . . . . . . . . . 345
Tire Sealant and Compressor Kit . . . . . . . . . . . . . 347