2012 GMC ACADIA light

Black plate (6,1)GMC Acadia/Acadia Denali Owner Manual - 2012
9-6 Driving and Operating
.Try to avoid sudden steering,
acceleration, or braking,
including reducing vehicle
speed by shifting to a lower
gear. Any sudden changes
could cause the tires to slide.
Remember: Antilock brakes help
avoid only the braking skid.
Driving on Wet Roads
Rain and wet roads can reduce
vehicle traction and affect your
ability to stop and accelerate.
Always drive slower in these
types of driving conditions and
avoid driving through large
puddles and deep‐standing or
flowing water.
{WARNING
Wet brakes can cause crashes.
They might not work as well in a
quick stop and could cause
pulling to one side. You could
lose control of the vehicle.
After driving through a large
puddle of water or a car/vehicle
wash, lightly apply the brake
pedal until the brakes work
normally.
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be
very cautious about trying to drive
through flowing water.
Hydroplaning
Hydroplaning is dangerous.
Water can build up under the
vehicle's tires so they actually ride
on the water. This can happen if the
road is wet enough and you are
going fast enough. When the
vehicle is hydroplaning, it has little
or no contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is to
slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet
weather driving tips include:
.Allow extra following distance.
.Pass with caution.
.Keep windshield wiping
equipment in good shape.

Black plate (9,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-9
WARNING (Continued)
carbon monoxide (CO) which
cannot be seen or smelled.
It can cause unconsciousness
and even death.
If the vehicle is stuck in the snow:
.Clear away snow from around
the base of your vehicle,
especially any that is blocking
the exhaust pipe.
.Check again from time to
time to be sure snow does
not collect there.
.Open a window about
5 cm (2 in) on the side of the
vehicle that is away from the
wind to bring in fresh air.(Continued)
WARNING (Continued)
.Fully open the air outlets on
or under the instrument
panel.
.Adjust the climate control
system to a setting that
circulates the air inside the
vehicle and set the fan
speed to the highest setting.
See“Climate Control
Systems” in the Index.
For more information about
carbon monoxide, see Engine
Exhaust on page 9‑22.
Run the engine for short periods
only as needed to keep warm, but
be careful. To save fuel, run the engine for only
short periods as needed to warm
the vehicle and then shut the engine
off and close the window most of
the way to save heat. Repeat this
until help arrives but only when you
feel really uncomfortable from the
cold. Moving about to keep warm
also helps.
If it takes some time for help to
arrive, now and then when you run
the engine, push the accelerator
pedal slightly so the engine runs
faster than the idle speed. This
keeps the battery charged to restart
the vehicle and to signal for help
with the headlamps. Do this as little
as possible to save fuel.

Black plate (10,1)GMC Acadia/Acadia Denali Owner Manual - 2012
9-10 Driving and Operating
If the Vehicle Is Stuck
Slowly and cautiously spin the
wheels to free the vehicle when
stuck in sand, mud, ice, or snow.
If the vehicle has a traction system,
it can often help to free a stuck
vehicle. Refer to the vehicle's
traction system in the Index. If stuck
too severely for the traction system
to free the vehicle, turn the traction
system off and use the rocking
method.
{WARNING
If the vehicle's tires spin at high
speed, they can explode, and
you or others could be injured.
The vehicle can overheat,
causing an engine compartment
fire or other damage. Spin the
wheels as little as possible and
avoid going above 55 km/h
(35 mph).For information about using tire
chains on the vehicle, see
Tire
Chains on page 10‑57.
Rocking the Vehicle to Get
It Out
Turn the steering wheel left and
right to clear the area around the
front wheels. Turn off any traction or
stability system. Shift back and forth
between R (Reverse) and a forward
gear, spinning the wheels as little as
possible. To prevent transmission
wear, wait until the wheels stop
spinning before shifting gears.
Release the accelerator pedal
while shifting, and press lightly on
the accelerator pedal when the
transmission is in gear. Slowly
spinning the wheels in the forward
and reverse directions causes a
rocking motion that could free the
vehicle. If that does not get the
vehicle out after a few tries, it might
need to be towed out. If the vehicle
does need to be towed out, see
Towing the Vehicle on page 10‑82.
Vehicle Load Limits
It is very important to know how
much weight your vehicle can
carry. This weight is called the
vehicle capacity weight and
includes the weight of all
occupants, cargo, and all
nonfactory-installed options.
Two labels on your vehicle
show how much weight it may
properly carry, the Tire and
Loading Information label and
the Certification/Tire label.
{WARNING
Do not load the vehicle any
heavier than the Gross
Vehicle Weight Rating
(GVWR), or either the
maximum front or rear Gross
Axle Weight Rating (GAWR).
(Continued)

Black plate (17,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-17
If the vehicle cannot be pulled
over, and must be shut off while
driving, turn the ignition to
ACC/ACCESSORY.
The steering can bind with the
wheels turned off center. If this
happens, move the steering wheel
from right to left while turning the
key to ACC/ACCESSORY. If this
does not work, then the vehicle
needs service.
ACC (ACC/ACCESSORY):This is
the position in which you can
operate the electrical accessories or
items plugged into the accessory
power outlets. This position unlocks
the ignition and steering wheel. Use
this position if the vehicle must be
pushed or towed.
R(ON/RUN): This position can be
used to operate the electrical
accessories and to display some
instrument panel warning and indicator lights. This position can
also be used for service and
diagnostics, and to verify the
proper operation of the malfunction
indicator lamp as may be required
for emission inspection purposes.
The switch stays in this position
when the engine is running.
The transmission is also unlocked
in this position. If you leave the
key in the ACC/ACCESSORY or
ON/RUN position with the engine
off, the battery could be drained.
You may not be able to start the
vehicle if the battery is allowed to
drain for an extended period of time.
/(START):
This is the position
that starts the engine. When the
engine starts, release the key.
The ignition switch will return to
ON/RUN for driving.
Key Lock Release
Vehicles with an automatic
transmission are equipped with an
electronic key lock release system.
This system is to prevent ignition
key removal unless the shift lever is
in P (Park).
The key lock release will not work
if the battery is charged less than
9‐volts, or uncharged. Try charging
or jump starting the battery. See
Jump Starting on page 10‑78.

Black plate (27,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-27
Automatic Engine Grade
Braking
Automatic Engine Grade Braking
assists when driving on a downhill
grade. It maintains vehicle speed by
automatically implementing a shift
schedule that uses the engine and
the transmission to slow the vehicle.
The system will automatically
command downshifts to reduce
vehicle speed, until the brake pedal
is no longer being pressed.
While in the Electronic Range
Select (ERS) mode, grade braking
is deactivated, allowing the driver
to select a range and limiting the
highest gear available. Grade
braking is available for normal
driving and in Tow/Haul mode.
SeeAutomatic Transmission on
page 9‑23.
Drive Systems
All-Wheel Drive
Vehicles with this feature always
send engine power to all four
wheels. It is fully automatic, and
adjusts itself as needed for road
conditions.
When using a compact spare tire
on an AWD vehicle, the system
automatically detects the compact
spare and disables AWD. To restore
AWD operation and prevent
excessive wear on the system,
replace the compact spare with a
full-size tire as soon as possible.
See Compact Spare Tire on
page 10‑77 for more information.
Brakes
Antilock Brake
System (ABS)
This vehicle has the Antilock Brake
System (ABS), an advanced
electronic braking system that helps
prevent a braking skid.
When the engine is started and the
vehicle begins to drive away, ABS
checks itself. A momentary motor or
clicking noise might be heard while
this test is going on, and it might
even be noticed that the brake
pedal moves a little. This is normal.
If there is a problem with ABS, this
warning light stays on. See Antilock
Brake System (ABS) Warning Light
on page 5‑22.

Black plate (28,1)GMC Acadia/Acadia Denali Owner Manual - 2012
9-28 Driving and Operating
If driving safely on a wet road and it
becomes necessary to slam on the
brakes and continue braking to
avoid a sudden obstacle, a
computer senses that the wheels
are slowing down. If one of the
wheels is about to stop rolling, the
computer will separately work the
brakes at each wheel.
ABS can change the brake pressure
to each wheel, as required, faster
than any driver could. This can help
the driver steer around the obstacle
while braking hard.
As the brakes are applied, the
computer keeps receiving updates
on wheel speed and controls
braking pressure accordingly.
Remember: ABS does not change
the time needed to get a foot up to
the brake pedal or always decrease
stopping distance. If you get too
close to the vehicle in front of you,there will not be enough time to
apply the brakes if that vehicle
suddenly slows or stops. Always
leave enough room up ahead to
stop, even with ABS.
Using ABS
Do not pump the brakes. Just hold
the brake pedal down firmly and let
ABS work. You might hear the ABS
pump or motor operating and feel
the brake pedal pulsate, but this is
normal.
Braking in Emergencies
ABS allows the driver to steer and
brake at the same time. In many
emergencies, steering can help
more than even the very best
braking.
Parking Brake
To set the parking brake, hold the
regular brake pedal down, then
push the parking brake pedal down.
If the ignition is on, the brake
system warning light will come on.
See
Brake System Warning Light on
page 5‑21.

Black plate (29,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-29
Notice:Driving with the parking
brake on can overheat the brake
system and cause premature
wear or damage to brake system
parts. Make sure that the parking
brake is fully released and the
brake warning light is off before
driving.
To release the parking brake, hold
the regular brake pedal down, then
push down momentarily on the
parking brake pedal until you feel
the pedal release. Slowly pull your
foot up off the park brake pedal.
If the parking brake is not released
when you begin to drive, the brake
system warning light will be on and
a chime will sound warning you that
the parking brake is still on.
If you are towing a trailer and are
parking on a hill, see Driving
Characteristics and Towing Tips on
page 9‑45.Brake Assist
This vehicle has a brake assist
feature designed to assist the
driver in stopping or decreasing
vehicle speed in emergency driving
conditions. This feature uses the
stability system hydraulic brake
control module to supplement
the power brake system under
conditions where the driver has
quickly and forcefully applied the
brake pedal in an attempt to quickly
stop or slow down the vehicle.
The stability system hydraulic brake
control module increases brake
pressure at each corner of the
vehicle until the ABS activates.
Minor brake pedal pulsation or
pedal movement during this time
is normal and the driver should
continue to apply the brake pedal
as the driving situation dictates.
The brake assist feature will
automatically disengage when
the brake pedal is released or
brake pedal pressure is quickly
decreased.
Hill Start Assist (HSA)
This vehicle has a Hill Start Assist
(HSA) feature, which may be useful
when the vehicle is stopped on a
grade. This feature is designed to
prevent the vehicle from rolling,
either forward or rearward, during
vehicle drive off. After the driver
completely stops and holds the
vehicle in a complete standstill on a
grade, HSA will be automatically
activated. During the transition
period between when the driver
releases the brake pedal and starts
to accelerate to drive off on a grade,
HSA holds the braking pressure
to ensure that there is no rolling.
The brakes will automatically
release when the accelerator pedal
is applied within the two‐second
window. It will not activate if the
vehicle is in a drive gear and facing
downhill or if the vehicle is facing
uphill and in R (Reverse).

Black plate (30,1)GMC Acadia/Acadia Denali Owner Manual - 2012
9-30 Driving and Operating
Ride Control Systems
StabiliTrak®System
The vehicle has the StabiliTrak
system which combines antilock
brake, traction, and stability control
systems and helps the driver
maintain directional control of the
vehicle in most driving conditions.
When you first start the vehicle and
begin to drive away, the system
performs several diagnostic checks
to ensure there are no problems.
The system may be heard or felt
while it is working. This is normal
and does not mean there is a
problem with the vehicle. The
system should initialize before the
vehicle reaches 32 km/h (20 mph).
In some cases, it may take
approximately 3.2 km (2 mi) of
driving before the system initializes.
If the system fails to turn on or
activate, one of the following
messages will be displayed on theDriver Information Center (DIC):
SERVICE TRACTION CONTROL,
SERVICE STABILITRAK, the
StabiliTrak light will come on and
stay and four chimes are heard.
If these conditions are observed,
turn the vehicle off, wait
15 seconds, and then turn it back
on again to reset the system. If any
of these messages still appear on
the Driver Information Center (DIC),
the vehicle should be taken in for
service. For more information on the
DIC messages, see
Ride Control
System Messages on page 5‑42.
The StabiliTrak light will flash on the
instrument panel cluster when the
system is both on and activated.
The system may be heard or felt
while it is working; this is normal.
The traction control button is
located on the instrument panel.
The traction control part of
StabiliTrak can be turned off by
pressing and releasing the traction
control button.
Traction control can be turned on by
pressing and releasing the traction
control button and the appropriate
TRACTION CONTROL ON
message will be displayed, if not
automatically shut off for any other
reason.
When the traction control system
is turned off, the appropriate
TRACTION CONTROL OFF
message will be displayed on the
DIC. The vehicle will still have
brake-traction control when traction
control is off, but will not be able to
use the engine speed management