
Black plate (45,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Instruments and Controls 5-45
SERVICE TIRE MONITOR
SYSTEM
On vehicles with the Tire Pressure
Monitor System (TPMS), this
message displays if a part on the
TPMS is not working properly.
The tire pressure light also flashes
and then remains on during the
same ignition cycle. SeeTire
Pressure Light on page 5‑23.
Several conditions may cause
this message to appear. See Tire
Pressure Monitor Operation on
page 10‑48 for more information.
If the warning comes on and stays
on, there may be a problem with
the TPMS. See your dealer.
TIRE LEARNING ACTIVE
This message displays when the
Tire Pressure Monitor System
(TPMS) is re-learning the tire
positions on your vehicle. The tire
positions must be re-learned after
rotating the tires or after replacing a
tire or sensor. See Tire Rotation on
page 10‑52, Tire Pressure Monitor
System on page 10‑47, and Tire
Pressure on page 10‑45 for more
information.
Transmission Messages
ALL WHEEL DRIVE OFF
If your vehicle has the All-Wheel
Drive (AWD) system, this message
displays when there is a compact
spare tire on the vehicle, when
the Antilock Brake System (ABS)
warning light comes on, or when the
rear differential fluid is overheating.
This message turns off when the
differential fluid cools. The AWD system is disabled until
the compact spare tire is replaced
by a full-size tire. If the warning
message is still on after putting on
the full-size tire, you need to reset
the warning message. To reset the
warning message, turn the ignition
off and then back on again after
30 seconds. If the message stays
on, see your dealer right away.
See
All-Wheel Drive on page 9‑28
for more information.
SERVICE ALL WHEEL DRIVE
If your vehicle has the All-Wheel
Drive (AWD) system, this message
displays if there is a problem
with this system. If this message
appears, stop as soon as possible
and turn off the vehicle. Restart the
vehicle after 30 seconds and check
for the message on the DIC display.
If the message is still displayed or
appears again when you begin
driving, the AWD system needs
service. See your dealer.

Black plate (3,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Driving and Operating 9-3
Medical research shows that
alcohol in a person's system
can make crash injuries worse,
especially injuries to the brain,
spinal cord, or heart. This means
that when anyone who has been
drinking—driver or passenger —is
in a crash, that person's chance of
being killed or permanently disabled
is higher than if the person had not
been drinking.
Control of a Vehicle
The following three systems
help to control the vehicle while
driving —brakes, steering, and
accelerator. At times, as when
driving on snow or ice, it is easy to
ask more of those control systems
than the tires and road can provide.
Meaning, you can lose control of the
vehicle. See StabiliTrak
®System on
page 9‑31.
Adding non‐dealer accessories
can affect vehicle performance.
See Accessories and Modifications
on page 10‑3.
Braking
See Brake System Warning Light on
page 5‑20.
Braking action involves
perception time and reaction
time. Deciding to push the brake
pedal is perception time. Actually
doing it is reaction time.
Average reaction time is about
three‐fourths of a second.
But that is only an average.
It might be less with one driver
and as long as two or three seconds
or more with another. Age, physical
condition, alertness, coordination,
and eyesight all play a part. So do
alcohol, drugs, and frustration.
But even in three‐fourths of a
second, a vehicle moving at
100 km/h (60 mph) travels 20 m
(66 ft). That could be a lot of
distance in an emergency, so
keeping enough space between
the vehicle and others is important. And, of course, actual stopping
distances vary greatly with the
surface of the road, whether it is
pavement or gravel; the condition
of the road, whether it is wet, dry,
or icy; tire tread; the condition of the
brakes; the weight of the vehicle;
and the amount of brake force
applied.
Avoid needless heavy
braking. Some people drive in
spurts
—heavy acceleration
followed by heavy braking —rather
than keeping pace with traffic.
This is a mistake. The brakes
might not have time to cool between
hard stops. The brakes will wear
out much faster with a lot of heavy
braking. Keeping pace with the
traffic and allowing realistic following
distances eliminates a lot of
unnecessary braking. That means
better braking and longer brake life.

Black plate (4,1)GMC Acadia/Acadia Denali Owner Manual - 2011
9-4 Driving and Operating
If the engine ever stops while
the vehicle is being driven, brake
normally but do not pump the
brakes. If the brakes are pumped,
the pedal could get harder to push
down. If the engine stops, there will
still be some power brake assist but
it will be used when the brake is
applied. Once the power assist is
used up, it can take longer to stop
and the brake pedal will be harder
to push.
Adding non‐dealer accessories
can affect vehicle performance.
SeeAccessories and Modifications
on page 10‑3.Steering
Power Steering
If power steering assist is lost
because the engine stops or
the power steering system is not
functioning, the vehicle can be
steered but it will take more effort.
Variable Effort Steering
The vehicle has a steering system
that continuously adjusts the effort
felt when steering at all vehicle
speeds. It provides ease when
parking, yet a firm, solid feel at
highway speeds.
Steering Tips
It is important to take curves at a
reasonable speed.
Traction in a curve depends on
the condition of the tires and the
road surface, the angle at which the
curve is banked, and vehicle speed.
While in a curve, speed is the one
factor that can be controlled.
If there is a need to reduce speed,
do it before entering the curve, while
the front wheels are straight.
Try to adjust the speed so you can
drive through the curve. Maintain a
reasonable, steady speed. Wait to
accelerate until out of the curve,
and then accelerate gently into
the straightaway.

Black plate (6,1)GMC Acadia/Acadia Denali Owner Manual - 2011
9-6 Driving and Operating
Ease off the accelerator and
then, if there is nothing in the
way, steer so that the vehicle
straddles the edge of the pavement.
Turn the steering wheel 8 to 13 cm
(3 to 5 in), about one-eighth turn,
until the right front tire contacts
the pavement edge. Then turn the
steering wheel to go straight down
the roadway.
Loss of Control
Let us review what driving experts
say about what happens when the
three control systems—brakes,
steering, and acceleration —do not
have enough friction where the tires
meet the road to do what the driver
has asked.
In any emergency, do not give up.
Keep trying to steer and constantly
seek an escape route or area of
less danger.
Skidding
In a skid, a driver can lose control of
the vehicle. Defensive drivers avoid
most skids by taking reasonable
care suited to existing conditions,
and by not overdriving those
conditions. But skids are always
possible.
The three types of skids
correspond to the vehicle's three
control systems. In the braking skid,
the wheels are not rolling. In the
steering or cornering skid, too much
speed or steering in a curve causes
tires to slip and lose cornering force.
And in the acceleration skid, too
much throttle causes the driving
wheels to spin.
If the vehicle starts to slide, ease
your foot off the accelerator pedal
and quickly steer the way you
want the vehicle to go. If you start
steering quickly enough, the vehicle
may straighten out. Always be ready
for a second skid if it occurs. Of course, traction is reduced when
water, snow, ice, gravel, or other
material is on the road. For safety,
slow down and adjust your driving
to these conditions. It is important
to slow down on slippery surfaces
because stopping distance is longer
and vehicle control more limited.
While driving on a surface with
reduced traction, 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. You might
not realize the surface is slippery
until the vehicle is skidding. Learn
to recognize warning clues
—such
as enough water, ice, or packed
snow on the road to make a
mirrored surface —and slow
down when you have any doubt.
Remember: Antilock brakes help
avoid only the braking skid.

Black plate (7,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Driving and Operating 9-7
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.(Continued)
WARNING (Continued)
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.
.Keep the windshield washer fluid
reservoir filled.
.Have good tires with proper
tread depth. See
Tires on
page 10‑38.
.Turn off cruise control.

Black plate (8,1)GMC Acadia/Acadia Denali Owner Manual - 2011
9-8 Driving and Operating
Highway Hypnosis
Always be alert and pay attention
to your surroundings while driving.
If you become tired or sleepy, find
a safe place to park the vehicle
and rest.
Other driving tips include:
.Keep the vehicle well ventilated.
.Keep interior temperature cool.
.Keep your eyes moving—scan
the road ahead and to the sides.
.Check the rearview mirror and
vehicle instruments often.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips for
driving in these conditions include:
.Keep the vehicle serviced and in
good shape.
.Check all fluid levels and brakes,
tires, cooling system, and
transmission.
.Shift to a lower gear when going
down steep or long hills.
{WARNING
If you do not shift down, the
brakes could get so hot that they
would not work well. You would
then have poor braking or even
none going down a hill. You could
crash. Shift down to let the engine
assist the brakes on a steep
downhill slope.
{WARNING
Coasting downhill in N (Neutral)
or with the ignition off is
dangerous. The brakes will
have to do all the work of slowing
down and they could get so hot
(Continued)

Black plate (9,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Driving and Operating 9-9
WARNING (Continued)
that they would not work well.
You would then have poor braking
or even none going down a hill.
You could crash. Always have the
engine running and the vehicle in
gear when going downhill.
.Stay in your own lane. Do not
swing wide or cut across the
center of the road. Drive at
speeds that let you stay in
your own lane.
.Top of hills: Be
alert—something could
be in your lane (stalled car,
accident).
.Pay attention to special road
signs (falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.
Winter Driving
Driving on Snow or Ice
Drive carefully when there is
snow or ice between the tires
and the road, creating less traction
or grip. Wet ice can occur at about
0°C (32°F) when freezing rain
begins to fall, resulting in even less
traction. Avoid driving on wet ice or
in freezing rain until roads can be
treated with salt or sand.
Drive with caution, whatever the
condition. Accelerate gently so
traction is not lost. Accelerating
too quickly causes the wheels to
spin and makes the surface under
the tires slick, so there is even less
traction.
Try not to break the fragile traction.
If you accelerate too fast, the drive
wheels will spin and polish the
surface under the tires even more. The
Antilock Brake System (ABS)
on page 9‑29 improves vehicle
stability during hard stops on
slippery roads, but apply the brakes
sooner than when on dry pavement.
Allow greater following distance on
any slippery road and watch for
slippery spots. Icy patches can
occur on otherwise clear roads in
shaded areas. The surface of a
curve or an overpass can remain
icy when the surrounding roads
are clear. Avoid sudden steering
maneuvers and braking while
on ice.
Turn off cruise control on slippery
surfaces.

Black plate (11,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Driving and Operating 9-11
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.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 10‑60.