service GMC TERRAIN 2018 Workshop Manual

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
234 Driving and Operating
When the System Does Not
Seem to Work Properly
The LCA system requires some
driving for the system to calibrate to
maximum performance. This
calibration may occur more quickly if
the vehicle is driving on a straight
highway road with traffic and
roadside objects (e.g., guardrails,
barriers).
LCA displays may not come on
when passing a vehicle quickly, for
a stopped vehicle, or when towing a
trailer. 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. LCA may alert to objects
attached to the vehicle, such as a
trailer, bicycle, or object extending
out to either side of the vehicle.
Attached objects may also interfere
with the detection of vehicles. This
is normal system operation; the
vehicle does not need service.
LCA may not always alert the driver
to vehicles in the next lane over,
especially in wet conditions or whendriving on sharp curves. The system
does not need to be serviced. The
system may light up due to
guardrails, signs, trees, shrubs, and
other non-moving objects. This is
normal system operation; the
vehicle does not need service.
LCA may not operate when the LCA
sensors in the left or right corners of
the rear bumper are covered with
mud, dirt, snow, ice, or slush, or in
heavy rainstorms. For cleaning
instructions, see "Washing the
Vehicle" under
Exterior Care0341.
If the Driver Information Center
(DIC) displays the system
unavailable message after cleaning
both sides of the vehicle toward the
rear corners of the vehicle, see your
dealer.
If the LCA displays do not light up
when moving vehicles are in the
side blind zone or are rapidly
approaching this zone and the
system is clean, the system may
need service. Take the vehicle to
your dealer.
Radio Frequency Information
See Radio Frequency Statement
0 379.
Lane Departure
Warning (LDW)
If equipped, LDW may help avoid
crashes due to unintentional lane
departures. It may provide a
warning if the vehicle is crossing a
detected lane marking without using
a turn signal in the lane departure
direction. Since this system is part
of the Lane Keep Assist (LKA)
system, read the entire LKA section
before using this feature.
Lane Keep Assist (LKA)
If equipped, LKA may help avoid
crashes due to unintentional lane
departures. It may assist by gently
turning the steering wheel if the
vehicle approaches a detected lane
marking without using a turn signal
in that direction. It may also provide
a Lane Departure Warning (LDW)
system alert as the lane marking is
crossed. The LKA system will not

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
236 Driving and Operating
three times, on the right or left,
depending on the lane departure
direction.
Take Steering
The LKA system does not
continuously steer the vehicle.
If LKA does not detect active driver
steering, then an alert, chime,
or Driver Information Center (DIC)
message may be provided. Steer
the vehicle to dismiss.
When the System Does Not
Seem to Work Properly
The system performance may be
affected by:
.Close vehicles ahead.
. Sudden lighting changes, such
as when driving through tunnels.
. Banked roads.
. Roads with poor lane markings,
such as two-lane roads.
If the LKA system is not functioning
properly when lane markings are
clearly visible, cleaning the
windshield may help. A system unavailable message may
display if the camera is blocked.
The LKA system does not need
service.
LKA assistance and/or LDW alerts
may occur due to tar marks,
shadows, cracks in the road,
temporary or construction lane
markings, or other road
imperfections. This is normal system
operation; the vehicle does not need
service. Turn LKA off if these
conditions continue.
Fuel
Fuel (Gasoline)
GM recommends the use of TOP
TIER detergent gasoline to keep the
engine cleaner and reduce engine
deposits. See www.toptiergas.com
for a list of TOP TIER detergent
gasoline marketers and applicable
countries.
Do not use any fuel labeled E85 or
FlexFuel. Do not use gasoline with
ethanol levels greater than 15% by
volume.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
Driving and Operating 237
For the LYX 1.5L L4 turbo engine,
use regular unleaded gasoline
meeting ASTM specification D4814
with a posted octane rating of 87 or
higher. Do not use gasoline with a
posted octane rating of less than 87,
as this may cause engine knock and
will lower fuel economy.
For the LTG 2.0L L4 turbo engine,
premium unleaded gasoline meeting
ASTM specification D4814 with a
posted octane rating of 93 is highly
recommended for best performance
and fuel economy. Unleaded
gasoline with an octane rated as low
as 87 can be used. 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
Caution
Do not use fuels with any of the
following conditions; doing so
may damage the vehicle and void
its warranty:
. For vehicles which are not
FlexFuel, fuel labeled
greater than 15% ethanol by
volume, such as mid-level
ethanol blends (16 –50%
ethanol), E85, or FlexFuel.
. Fuel with any amount of
methanol, methylal, 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.
(Continued)
Caution (Continued)
.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.
California Fuel
Requirements (Gasoline)
If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that
meet California specifications. See
the underhood emission control
label. If this fuel is not available in
states adopting California Emissions
Standards, the vehicle will operate
satisfactorily on fuels meeting
federal specifications, but emission
control system performance may be
affected. The malfunction indicator
lamp could turn on and the vehicle
may not pass a smog-check test.
See Malfunction Indicator Lamp
(Check Engine Light) 0127. If this

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
Driving and Operating 239
Caution (Continued)
.Aftermarket diesel fuel
additives, which contain
alcohols, organo-metallic
additives, or water
emulsifiers.
. Diesel fuel with sulfur
greater than 15 ppm.
. Diesel-biodiesel blends not
within the required
specification.
Some conditions, such as dirty fuel,
may decrease fuel filter life and a
CHANGE FUEL FILTER message
may come on in the Driver
Information Center (DIC).
What Fuel to Use in the
U.S. (Diesel)
Use of diesel fuel with ultra low
sulfur content (15 ppm, maximum) is
required. Look for service station
fuel dispensers with this label in
green:
The diesel fuel must meet ASTM
International specification D 975,
Grades No. 2-D or No. 1-D S15,
also known as Ultra Low Sulfur
Diesel. Contact a fuel supplier or
fueling station with any questions. Diesel Fuel Grades
For best results use No. 2-D diesel
fuel year-round because it is
blended for seasonal temperature
differences, both above and below
freezing conditions. No. 1-D diesel
also meeting ASTM International
D975 fuel can be used in very cold
temperatures (below
−18 °C or
0 °F); however, it will reduce power
and fuel economy. Avoid using No.
1-D diesel fuel in warm or hot
climates. It can result in stalling,
poor starting when the engine is hot,
and damage to the fuel injection
system.
Premium Diesel Fuel
Premium Diesel Fuel (FQP-1A)
corresponds to the Engine
Manufacturers Association (EMA)
Recommended Guideline. It may
provide less noise, better starting,
and better vehicle performance, but
is not required.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
242 Driving and Operating
Caution (Continued)
fuel system and engine, and
damages would not be covered
by the vehicle warranty.
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.
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.
Owners who use very little fuel,
or who have vehicles stored for
extended periods of time, should avoid the use of biodiesel blended
fuels above 5% by volume. When
vehicles are stored for longer than
one month, they should be run out
of biodiesel to below one-quarter
tank, refueled with Ultra Low Sulfur
Diesel fuel, and driven at least
32 km (20 mi) before storage.
At temperatures below 0 °C (32 °F),
it is recommended to switch to Ultra
Low Sulfur Diesel fuel with no
biodiesel content, or to blends with
biodiesel containing less than 5% by
volume. At these extreme cold
temperatures, biodiesel blends
higher than 5% by volume may
cause fuel filter plugging and
system gelling, which can lead to
vehicle operability problems.
Fuels improperly blended for cold
temperature operation may result in
restricted fuel filters and degraded
vehicle performance. GM diesel
vehicles are equipped with a fuel
heating system to provide an extra
level of protection against filter
plugging from gelling or waxing of
conventional diesel fuel and
biodiesel blends. If the operating
temperature is far below the
temperature at which gelling or
waxing of the fuel occurs, the
system cannot prevent all cases of
filter plugging.
If the vehicle experiences a fuel
filter restriction, the on-board
monitoring system will alert the
driver that the fuel filter requires
service. The fuel filter, however, will
not prevent all damage caused by
poor quality biodiesel.
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) 0246.
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

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
Driving and Operating 243
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.
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.
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.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
Driving and Operating 245
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 0186. 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 0186. 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-10664916) - 2018 - crc - 9/15/17
254 Driving and Operating
3. When the wheel chocks are inplace, release the brake pedal
until the chocks absorb
the load.
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 while you:
.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 pulling a trailer. See
Maintenance Schedule 0353.
Things that are especially important
in trailer operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system, and
brake system. Inspect these before
and during the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Engine Cooling When Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. See Engine Overheating
0 280.
Trailer Towing
Before pulling a trailer, there are
three important considerations that
have to do with weight:
.
The weight of the trailer
. The weight of the trailer tongue .
The total weight on the vehicle's
tires
Weight of the Trailer
Safe trailering requires monitoring
the weight, speed, altitude, road
grades, outside temperature, the
dimensions of the front of the trailer,
and how frequently the vehicle is
used to pull a trailer. Take into
consideration any special equipment
on the vehicle, and the amount of
tongue weight the vehicle can carry.
See “Weight of the Trailer Tongue”
later in this section for more
information.
Trailer weight rating (TWR) is
calculated assuming the tow vehicle
has the driver, a front seat
passenger, and all required trailering
equipment. Weight of additional
optional equipment, passengers,
and cargo in the tow vehicle must
be subtracted from the trailer weight
rating.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
Driving and Operating 257
Safety Chains
Always attach chains between the
vehicle and the trailer. Cross the
safety chains under the tongue of
the trailer to help prevent the tongue
from contacting the road if it
becomes separated from the hitch.
Leave enough slack so the rig can
turn. Never allow safety chains to
drag on the ground.
Trailer Brakes
A loaded trailer that weighs more
than 454 kg (1,000 lb) must be
equipped with its own brake system,
with brakes working on all axles.
Trailer braking equipment
conforming to Canadian Standards
Association (CSA) requirement
CAN3-D313, or its equivalent, is
recommended. State and local
regulations may also require the
trailer to have its own braking
system if loaded above a certain
threshold. These requirements vary
from state to state. Read and follow
the instructions for the trailer brakes
so they are installed, adjusted, and
maintained properly.Do not tap into the vehicle's
hydraulic brake system.
Trailer Sway
Control (TSC)
The vehicle has a Trailer Sway
Control (TSC) feature as part of the
StabiliTrak system. If TSC detects
that the trailer is swaying, the
vehicle's brakes are automatically
applied.
When TSC is applying the brakes,
the TCS/StabiliTrak indicator light
flashes to notify the driver to reduce
speed. If the trailer continues to
sway, StabiliTrak will reduce engine
torque to help slow the vehicle.
TSC will not function if StabiliTrak is
turned off. See
Traction Control/
Electronic Stability Control 0213.
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) 0127.
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-10664916) - 2018 - crc - 9/15/17
Vehicle Care 259
Vehicle Care
General Information
General Information . . . . . . . . . . 260
California Proposition65 Warning . . . . . . . . . . . . . . . . . 260
California Perchlorate Materials Requirements . . . . . 261
Accessories and Modifications . . . . . . . . . . . . . . . . 261
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 261
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 262
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 264
Engine Oil . . . . . . . . . . . . . . . . . . . . 269
Engine Oil Life System . . . . . . . 273
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 274
Engine Air Cleaner/Filter . . . . . . 274
Cooling System . . . . . . . . . . . . . . 276
Engine Overheating . . . . . . . . . . 280
Washer Fluid . . . . . . . . . . . . . . . . . 282
Brakes . . . . . . . . . . . . . . . . . . . . . . . 282
Brake Fluid . . . . . . . . . . . . . . . . . . . 283
Battery - North America . . . . . . 284
All-Wheel Drive . . . . . . . . . . . . . . . 285 Starter Switch Check . . . . . . . . . 285
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . 286
Wiper Blade Replacement . . . . 286
Windshield Replacement . . . . . 287
Gas Strut(s) . . . . . . . . . . . . . . . . . . 287
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 289
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 289
Halogen Bulbs . . . . . . . . . . . . . . . . 289
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 289
LED Lighting . . . . . . . . . . . . . . . . . 289
Front Turn Signal Lamps . . . . . 289
Taillamps . . . . . . . . . . . . . . . . . . . . . 290
License Plate Lamp . . . . . . . . . . 291
Electrical System
Electrical System Overload . . . 292
Fuses and Circuit Breakers . . . 292
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 293
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 296
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 298
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 300 All-Season Tires . . . . . . . . . . . . . . 301
Winter Tires . . . . . . . . . . . . . . . . . . 301
Summer Tires . . . . . . . . . . . . . . . . 302
Tire Sidewall Labeling . . . . . . . . 302
Tire Designations . . . . . . . . . . . . . 304
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . 305
Tire Pressure . . . . . . . . . . . . . . . . . 307
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . . . . 309
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . 310
Tire Inspection . . . . . . . . . . . . . . . . 313
Tire Rotation . . . . . . . . . . . . . . . . . 314
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . 315
Buying New Tires . . . . . . . . . . . . . 315
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . 317
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . . . 317
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . 319
Wheel Replacement . . . . . . . . . . 319
Tire Chains . . . . . . . . . . . . . . . . . . . 320
If a Tire Goes Flat . . . . . . . . . . . . 320
Tire Sealant and Compressor Kit . . . . . . . . . . . . . 322
Storing the Tire Sealant and Compressor Kit . . . . . . . . . . . . . 328