GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-12146071) - 2019 - crc - 7/27/18
Driving and Operating 239
{Warning
Leaving the vehicle without
placing it in P (Park) can be
dangerous. Do not leave the
vehicle while it is being held at a
stop by ACC. Always place the
vehicle in P (Park) and turn off
the ignition before leaving the
vehicle.
ACC Override
If using the accelerator pedal while
ACC is active, the ACC indicator
turns blue on the instrument cluster
indicating ACC braking will not
occur. ACC will resume operation
when the accelerator pedal is not
being pressed.
{Warning
The ACC will not automatically
apply the brakes if your foot is
resting on the accelerator pedal.
You could crash into a vehicle
ahead of you. Curves in the Road
{Warning
On curves, ACC may not detect a
vehicle ahead in your lane. You
could be startled if the vehicle
accelerates up to the set speed,
especially when following a
vehicle exiting or entering exit
ramps. You could lose control of
the vehicle or crash. Do not use
ACC while driving on an entrance
or exit ramp. Always be ready to
use the brakes if necessary.
{Warning
On curves, ACC may respond to
a vehicle in another lane, or may
not have time to react to a vehicle
in your lane. You could crash into
a vehicle ahead of you, or lose
control of your vehicle. Give extra
attention in curves and be ready
(Continued)
Warning (Continued)
to use the brakes if necessary.
Select an appropriate speed while
driving in curves.
ACC may operate differently in a
sharp curve. It may reduce the
vehicle speed if the curve is too
sharp.
When following a vehicle and
entering a curve, ACC may not
detect the vehicle ahead and
accelerate to the set speed. When
this happens, the vehicle ahead
indicator will not appear.
GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-12146071) - 2019 - crc - 7/27/18
Driving and Operating 257
Left Side MirrorDisplayRight Side Mirror Display
When the vehicle is started, both
outside mirror LCA displays will
briefly come on to indicate the
system is operating. When the
vehicle is in a forward gear, the left
or right side mirror display will light
up if a moving vehicle is detected in
the next lane over in that blind zone
or rapidly approaching that zone.
If the turn signal is activated in the
same direction as a detected
vehicle, this display will flash as an
extra warning not to change lanes.
LCA can be disabled through
vehicle personalization. See
“Collision/Detection Systems” under
Vehicle Personalization 0152.
If LCA is disabled by the driver, the
LCA mirror displays will not light up.
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 when driving 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 Care0367.
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.
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 269
Warning (Continued)
.Keep sparks, flames, and
smoking materials away
from fuel.
. Do not leave the fuel pump
unattended.
. Avoid using electronic
devices 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.
{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.
. Potential fuel fires.
Be careful not to spill fuel. Wait a
few seconds after you have finished
pumping before removing the
nozzle. Clean fuel from painted
surfaces as soon as possible. See
Exterior Care 0367.
{Warning
If a fire starts while you are
refueling, do not remove the
nozzle. Shut off the flow of fuel by
shutting off the pump or by
notifying the station attendant.
Leave the area immediately.
GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-12146071) - 2019 - crc - 7/27/18
Driving and Operating 271
The fuel cap is behind a hinged fuel
door on the driver side of the
vehicle. To open the fuel door, push
and release the rearward center
edge of the door.
Turn the fuel cap counterclockwise
to remove. Reinstall the cap by
turning it clockwise until it clicks.
{Warning
Overfilling the fuel tank by more
than three clicks of a standard fill
nozzle may cause:. Fuel spills
(Continued)
Warning (Continued)
.Potential fuel fires
Be careful not to spill fuel. Wait a
few seconds after you have finished
pumping before removing the
nozzle. Clean fuel from painted
surfaces as soon as possible. See
Exterior Care 0367.
{Warning
If a fire starts while you are
refueling, do not remove the
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
(Continued)
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)0133.
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.
GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-12146071) - 2019 - crc - 7/27/18
274 Driving and Operating
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.
. 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 0217.
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)
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.