
Black plate (4,1)GMC Acadia/Acadia Denali Owner Manual - 2012
9-4 Driving and Operating
If the engine ever stops while the
vehicle is being driven, brake
normally but do not pump the
brakes. Doing so could make the
pedal harder to push down. If the
engine stops, there will 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.
Steering
Hydraulic Power Steering
Your vehicle has hydraulic
power steering. It may require
maintenance. SeePower Steering
Fluid on page 10‑21.
If power steering assist is lost due
to a system malfunction, the vehicle
can be steered, but may require
increased effort.
Variable Effort Steering
Some vehicles have a steering
system that varies the amount of
effort required to steer the vehicle in
relation to the speed of the vehicle.
The amount of steering effort
required is less at slower speeds
to make the vehicle more
maneuverable and easier to park.
At faster speeds, the steering effort
increases to provide a sport-like feel
to the steering. This provides
maximum control and stability.
If the vehicle seems harder to steer
than normal when parking or driving
slowly, there may be a problem with
the system. You will still have power
steering, but steering will be stiffer
than normal at slow speeds.
See your dealer for service.
Curve Tips
.Take curves at a reasonable
speed.
.Reduce speed before entering a
curve.
.Maintain a reasonable steady
speed through the curve.
.Wait until the vehicle is out of
the curve before accelerating
gently into the straightaway.
Steering in Emergencies
.There are some situations when
steering around a problem may
be more effective than braking.
.Holding both sides of the
steering wheel allows you to turn
180 degrees without removing
a hand.
.Antilock Brake System (ABS)
allows steering while braking.

Black plate (40,1)GMC Acadia/Acadia Denali Owner Manual - 2012
9-40 Driving and Operating
Fuel
Use of the recommended fuel is
an important part of the proper
maintenance of this vehicle. To help
keep the engine clean and maintain
optimum vehicle performance, we
recommend the use of gasoline
advertised as TOP TIER Detergent
Gasoline.
Look for the TOP TIER label on the
fuel pump to ensure gasoline meets
enhanced detergency standards
developed by auto companies. A list
of marketers providing TOP TIER
Detergent Gasoline can be found at
www.toptiergas.com.
Recommended Fuel
Use regular unleaded gasoline with
a posted octane rating of 87 or
higher. If the octane rating is less
than 87, an audible knocking noise,
commonly referred to as spark
knock, might be heard when driving.
If this occurs, use a gasoline rated
at 87 octane or higher as soon as
possible. If heavy knocking is heard
when using gasoline rated at
87 octane or higher, the engine
needs service.
Gasoline Specifications
(U.S. and Canada Only)
At a minimum, gasoline should
meet ASTM specification
D 4814 in the United States or
CAN/CGSB‐3.5 or 3.511 in Canada.
Some gasolines contain an
octane-enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend
against the use of gasolines
containing MMT. SeeFuel Additives
on page 9‑41 for additional
information.
California Fuel
Requirements
If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that
meet California specifications.

Black plate (46,1)GMC Acadia/Acadia Denali Owner Manual - 2012
9-46 Driving and Operating
Pulling a Trailer
Here are some important points:
.There are many laws, including
speed limit restrictions that apply
to trailering. Check for legal
requirements.
.Consider using sway control.
SeeTowing Equipment on
page 9‑51.
.Do not tow a trailer at all during
the first 800 km (500 miles)
the new vehicle is driven.
The engine, axle, or other parts
could be damaged.
.During the first 800 km
(500 miles) that a trailer is
towed, do not drive over 80 km/h
(50 mph) and do not make starts
at full throttle. This reduces wear
on the vehicle.
.The vehicle can tow in D (Drive).
Use a lower gear if the
transmission shifts too often.
See “Tow/Haul Mode” later in
this section.
.Obey speed limit restrictions
when towing a trailer.
.The vehicle is designed primarily
as a passenger and load
carrying vehicle. If a trailer is
towed, the vehicle will require
more frequent maintenance due
to the additional load.
Driving with a Trailer
Towing a trailer requires experience.
Get familiar with handling and
braking with the added trailer
weight. The vehicle is now longer
and not as responsive as the
vehicle is by itself.
Check all trailer hitch parts and
attachments, safety chains,
electrical connectors, lamps, tires
and mirror adjustments. If the trailer
has electric brakes, start the vehicle
and trailer moving and then apply
the trailer brake controller by hand
to be sure the brakes are working. During the trip, check regularly to be
sure that the load is secure, and the
lamps and trailer brakes are working
properly.
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.
Tow/Haul Mode
Tow/Haul assists when pulling a
heavy trailer or a large or heavy
load. The purpose of the Tow/Haul
mode is to:
.Reduce the frequency and
improve the predictability of
transmission shifts.
.Provide the same solid shift feel
as when the vehicle is unloaded.

Black plate (49,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-49
If parking the rig on a hill:
1. Press the brake pedal, butdo 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, 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:
1.1. Start the engine.
1.2. Shift into a gear.
1.3. 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 on
page 11‑3. 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
on page 10‑18.
Trailer Towing
Three important considerations
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
How heavy can a trailer safely be?
Speed, altitude, road grades,
outside temperature, special
equipment, and the amount of
tongue weight the vehicle can carry
must be considered. See “Weight of
the Trailer Tongue” later in this
section for more information.
Maximum trailer weight is calculated
assuming only the driver is in the
tow vehicle and it has all the
required trailering equipment.
The weight of additional optional
equipment, passengers and cargo in
the tow vehicle must be subtracted
from the maximum trailer weight.

Black plate (4,1)GMC Acadia/Acadia Denali Owner Manual - 2012
10-4 Vehicle Care
Vehicle Checks
Doing Your Own
Service Work
{WARNING
It can be dangerous to work on
your vehicle if you do not have
the proper knowledge, service
manual, tools, or parts. Always
follow owner manual procedures
and consult the service manual
for your vehicle before doing any
service work.If doing some of your own service
work, use the proper service
manual. It tells you much more
about how to service the vehicle
than this manual can. To order the
proper service manual, see
Service
Publications Ordering Information
on page 13‑18.
This vehicle has an airbag system.
Before attempting to do your own
service work, see Servicing the
Airbag-Equipped Vehicle on
page 3‑35.
Keep a record with all parts receipts
and list the mileage and the date
of any service work performed.
See Maintenance Records on
page 11‑14.
Hood
To open the hood, do the following:
1. Pull the hood release handle with this symbol on it. It is
located under the instrument
panel on the driver's side of the
vehicle.
2. At the front of the vehicle, pull up on the center of the hood,
and push the secondary hood
release to the right.
3. After you have partially lifted the hood, gas struts will
automatically take over to lift and
hold the hood in the fully open
position.

Black plate (12,1)GMC Acadia/Acadia Denali Owner Manual - 2012
10-12 Vehicle Care
Automatic Transmission
Fluid
It is not necessary to check the
transmission fluid level.
A transmission fluid leak is the
only reason for fluid loss. If a leak
occurs, take the vehicle to the
dealer and have it repaired as soon
as possible.
Change the fluid at the intervals
listed inMaintenance Schedule on
page 11‑3, and be sure to use
the transmission fluid listed in
Recommended Fluids and
Lubricants on page 11‑12.
Notice: Use of the incorrect
automatic transmission fluid may
damage the vehicle, and the
damages may not be covered
by the vehicle warranty. Always use the automatic
transmission fluid listed in
Recommended Fluids and
Lubricants on page 11‑12.
The transmission fluid will not reach
the end of the dipstick unless the
transmission is at operating
temperature. If you need to check
the transmission fluid level, please
take the vehicle to your dealer.
Engine Air Cleaner/Filter
When to Inspect the Engine
Air Cleaner/Filter
Inspect the air cleaner/filter at the
scheduled maintenance intervals
and replace it at the first oil change
after each 80 000 km (50,000 mi)
interval. See
Maintenance Schedule
on page 11‑3 for more information. If driving in dusty/dirty conditions,
inspect the filter at each engine oil
change.
See
Engine Compartment Overview
on page 10‑6 for the location of the
engine air cleaner/filter.
How to Inspect the Engine
Air Cleaner/Filter
To inspect the air cleaner/filter,
remove the filter from the vehicle
and lightly shake the filter (away
from vehicle) to release loose dust
and dirt. If the filter remains covered
with dirt, a new filter is required.

Black plate (28,1)GMC Acadia/Acadia Denali Owner Manual - 2012
10-28 Vehicle Care
Wiper Blade Replacement
Windshield wiper blades should be
inspected for wear or cracking.
SeeMaintenance Schedule on
page 11‑3 for more information.
Replacement blades come in
different types and are removed in
different ways. To replace the wiper
blade assembly:
1. Pull the windshield wiper arm away from the windshield.
2. Press the button in the middle ofthe wiper arm connector and pull
the wiper blade away from the
arm connector.
3. Install the new wiper blade and make sure the wiper blade locks
into place.
For the proper size and type, see
Maintenance Replacement Parts on
page 11‑13.
Backglass Wiper Blade
To replace the backglass wiper
blade:
1. Pull the wiper blade assembly away from the backglass.
The backglass wiper blade will
not lock in a vertical position so
care should be used when
pulling it away from the vehicle.
2. Rotate the wiper blade assembly, hold the wiper arm in
position, and push the blade
away from the wiper arm.
3. Replace the wiper blade.
4. Return the wiper arm and blade assembly to the rest position on
the glass.
Windshield Replacement
If the vehicle is equipped with the
Head‐Up display (HUD) system and
the windshield needs to be
replaced, get one that is designed
for HUD or the HUD image may
look out of focus.
Headlamp Aiming
Headlamp aim has been preset and
should need no further adjustment.
If the vehicle is damaged in a crash,
the headlamp aim may be affected.
If adjustment to the headlamps is
necessary, see your dealer.

Black plate (45,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Vehicle Care 10-45
the vehicle has not been driven
for at least three hours or no
more than 1.6 km (1 mi).
Remove the valve cap from the
tire valve stem. Press the tire
gauge firmly onto the valve to
get a pressure measurement.
If the cold tire inflation pressure
matches the recommended
pressure on the Tire and
Loading Information label, no
further adjustment is necessary.
If the inflation pressure is low,
add air until the recommended
pressure is reached. If the
inflation pressure is high, press
on the metal stem in the center
of the tire valve to release air.
Recheck the tire pressure with
the tire gauge.
Return the valve caps on the
valve stems to prevent leaks
and keep out dirt and moisture.Tire Pressure Monitor
System
The Tire Pressure Monitor System
(TPMS) uses radio and sensor
technology to check tire pressure
levels. The TPMS sensors monitor
the air pressure in your tires and
transmit tire pressure readings to a
receiver located in the vehicle.
Each tire, including the spare
(if provided), should be checked
monthly when cold and inflated to
the inflation pressure recommended
by the vehicle manufacturer on the
vehicle placard or tire inflation
pressure label. (If your vehicle has
tires of a different size than the size
indicated on the vehicle placard or
tire inflation pressure label, you
should determine the proper tire
inflation pressure for those tires.)
As an added safety feature, your
vehicle has been equipped with a
tire pressure monitoring system
(TPMS) that illuminates a low tirepressure telltale when one or
more of your tires is significantly
under‐inflated.
Accordingly, when the low tire
pressure telltale illuminates, you
should stop and check your tires as
soon as possible, and inflate them
to the proper pressure. Driving on a
significantly under‐inflated tire
causes the tire to overheat and can
lead to tire failure. Under‐inflation
also reduces fuel efficiency and tire
tread life, and may affect the
vehicle's handling and stopping
ability.
Please note that the TPMS is
not a substitute for proper tire
maintenance, and it is the driver's
responsibility to maintain correct tire
pressure, even if under‐inflation has
not reached the level to trigger
illumination of the TPMS low tire
pressure telltale.