2018 GMC TERRAIN check engine

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
Driving and Operating 213
Ride Control Systems
Traction Control/
Electronic Stability
Control
System Operation
The vehicle has a Traction Control
System (TCS) and StabiliTrak, an
electronic stability control system.
These systems help limit wheel slip
and assist the driver in maintaining
control, especially on slippery road
conditions.
TCS activates if it senses that any
of the drive wheels are spinning or
beginning to lose traction. When this
happens, TCS applies the brakes to
the spinning wheels and reduces
engine power to limit wheel spin.
StabiliTrak activates when the
vehicle senses a difference between
the intended path and the direction
the vehicle is actually traveling.
StabiliTrak selectively applies
braking pressure to any one of thevehicle wheel brakes to assist the
driver in keeping the vehicle on the
intended path.
If cruise control is being used and
TCS or StabiliTrak begins to limit
wheel spin, cruise control will
disengage. Cruise control may be
turned back on when road
conditions allow.
Both systems come on
automatically when the vehicle is
started and begins to move. The
systems may be heard or felt while
they are operating or while
performing diagnostic checks. This
is normal and does not mean there
is a problem with the vehicle.
It is recommended to leave both
systems on for normal driving
conditions, but it may be necessary
to turn TCS off if the vehicle gets
stuck in sand, mud, ice, or snow.
See
If the Vehicle Is Stuck 0180
and “Turning the Systems Off and
On” later in this section.
The indicator light for both systems
is in the instrument cluster. This
light will:
.
Flash when TCS is limiting
wheel spin
. Flash when StabiliTrak is
activated
. Turn on and stay on when either
system is not working
If either system fails to turn on or to
activate, a message displays in the
Driver Information Center (DIC), and
dcomes on and stays on to
indicate that the system is inactive
and is not assisting the driver in
maintaining control. The vehicle is
safe to drive, but driving should be
adjusted accordingly.
If
dcomes on and stays on:
1. Stop the vehicle.

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 247
8. Start the engine and let it idlefor five minutes. Check the fuel
filter and air bleed valve for
leaks.
9. Reset the fuel filter monitor. See Driver Information Center
(DIC) 0136.
Filling the Tank
(Gasoline)
{Warning
Fuel vapors and fuel fires burn
violently and can cause injury or
death.
. To help avoid injuries to you
and others, read and follow
all the instructions on the
fuel pump island.
. Turn off the engine when
refueling.
. Keep sparks, flames, and
smoking materials away
from fuel.
(Continued)
Warning (Continued)
.Do not leave the fuel pump
unattended.
. Do not use a cell phone
while refueling.
. Do not reenter the vehicle
while pumping fuel.
. Keep children away from
the fuel pump and never let
children pump fuel.
. Fuel can spray out if the
refueling nozzle is inserted
too quickly. This spray can
happen if the tank is nearly
full, and is more likely in hot
weather. Insert the refueling
nozzle slowly and wait for
any hiss noise to stop prior
to beginning to flow fuel.
To open the fuel door, push and
release the rearward center edge of
the door.
The vehicle has a capless fuel
system and does not have a fuel
cap. The filling nozzle must be fully
inserted and latched prior to starting
fuel flow.

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
250 Driving and Operating
Caution (Continued)
of fuel cap may not fit properly,
may cause the malfunction
indicator lamp to light, and could
damage the fuel tank and
emissions system. See
Malfunction Indicator Lamp
(Check Engine Light)0127.
Diesel fuel can foam when filling the
tank. This can cause the automatic
pump nozzle to shut off, even if the
tank is not full. If this happens, wait
for the foaming to stop, and then fill
the tank more slowly.
{Warning
Heat coming from the engine can
cause the fuel to expand and
force the fuel out of the tank.
If something ignites the fuel, a fire
could start. To help avoid this, fill
the tank slowly and only until the
nozzle shuts off. Do not top it off.
Clean up any spilled fuel. Accidental Refueling with
Gasoline
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 fuel system. Have the
vehicle towed to a qualified
technician to have the gasoline
removed from the tank and fuel
system. Flush the fuel system with
Ultra Low Sulfur Diesel fuel to
ensure all gasoline is removed.
Diesel Exhaust Fluid (DEF)
DEF is a non-toxic solution that is
sprayed into the exhaust stream of
diesel vehicles to cause a chemical
reaction and break down NOx
emissions into harmless nitrogen
and water.
DEF is not a fuel additive and never
comes into contact with diesel fuel.
It is stored in a separate tank. The
fill port is behind the fuel door next
to the regular fuel cap. It has a blue
filler cap. See
Diesel Exhaust Fluid
0 198.
Filling a Portable Fuel
Container
{Warning
Filling a portable fuel container
while it is in the vehicle can cause
fuel vapors that can ignite either
by static electricity or other
means. You or others could be
badly burned and the vehicle
could be damaged. Always:
(Continued)

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
252 Driving and Operating
Warning (Continued)
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.
. Also adjust the climate
control system to a setting
that brings in only outside
air. See “Climate Control
Systems” in the Index.
For information about carbon
monoxide, see Engine Exhaust
0 196.
Towing a trailer requires a certain
amount of experience. The
combination you are driving is
longer and not as responsive as the
vehicle itself. Get acquainted with
the handling and braking of the rig
before setting out for the open road. Before starting, check all trailer hitch
parts and attachments, safety
chains, electrical connectors, lamps,
tires, and mirrors. If the trailer has
electric brakes, start the
combination moving and then apply
the trailer brake controller by hand
to be sure the brakes work.
During the trip, check occasionally
to be sure that the load is secure
and the lamps and any trailer
brakes still work.
Towing with a Stability Control
System
When towing, the sound of the
stability control system might be
heard. The system is reacting to the
vehicle movement caused by the
trailer, which mainly occurs during
cornering. This is normal when
towing heavier trailers.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid situations
that require heavy braking and
sudden turns.
Passing
More passing distance is needed
when towing a trailer. Because the
rig is longer, it is necessary to go
farther beyond the passed vehicle
before returning to the lane.
Backing Up
Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move your hand to
the left. To move the trailer to the
right, move your hand to the right.
Always back up slowly and,
if possible, have someone
guide you.
Making Turns
Caution
Making very sharp turns while
trailering could cause the trailer to
come in contact with the vehicle. (Continued)

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-10664916) - 2018 - crc - 9/15/17
Driving and Operating 253
Caution (Continued)
The vehicle could be damaged.
Avoid making very sharp turns
while trailering.
When turning with a trailer, make
wider turns than normal so the
trailer will not strike soft shoulders,
curbs, road signs, trees, or other
objects. Use the turn signal well in
advance and avoid jerky or sudden
maneuvers.
Turn Signals When Towing a
Trailer
The turn signal indicators in the
instrument cluster flash whenever
signaling a turn or lane change.
Properly hooked up, the trailer
lamps also flash, telling other
drivers the vehicle is turning,
changing lanes, or stopping.
When towing a trailer, the turn
signal indicators in the instrument
cluster flash for turns even if the bulbs on the trailer are burned out.
Check occasionally to be sure the
trailer bulbs are still working.
Driving on Grades
Reduce speed and shift to a lower
gear before starting down a long or
steep downgrade. If the
transmission is not shifted down, the
brakes might have to be used so
much that they would get hot and no
longer work well.
The vehicle can tow in D (Drive).
Use a lower gear if the transmission
shifts too often.
When towing at high altitude on
steep uphill grades, engine coolant
boils at a lower temperature than at
normal 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
while parked, preferably on level
ground, with the transmission in
P (Park) for a few minutes beforeturning the engine off. If the
overheat warning comes on, see
Engine Overheating
0280.
Parking on Hills
{Warning
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.
If parking the rig 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.

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.