2009 GMC ACADIA Truck

Roof-rail airbags are not intended
to inate in rear impacts. A
seat-mounted side impact airbag
is intended to deploy on the side
of the vehicle that is struck. Both
roof-rail airbags will deploy when
either side of the vehicle is struck, or
if the sensing system predicts that
the vehicle is about to roll over, or in
a severe frontal impact.
In any particular crash, no one can
say whether an airbag should
have inated simply because of the
damage to a vehicle or because
of what the repair costs were.
For frontal airbags, ination is
determined by what the vehicle hits,
the angle of the impact, and how
quickly the vehicle slows down. For
seat-mounted side impact and
roof-rail airbags, deployment
is determined by the location and
severity of the side impact. In
a rollover event, roof-rail airbag
deployment is determined by
the direction of the roll.What Makes an Airbag
Inate?
In a deployment event, the sensing
system sends an electrical signal
triggering a release of gas from the
inator. Gas from the inator lls
the airbag causing the bag to break
out of the cover and deploy. The
inator, the airbag, and related
hardware are all part of the airbag
module.
Frontal airbag modules are located
inside the steering wheel and
instrument panel. For vehicles with
seat-mounted side impact airbags,
there are airbag modules in the side
of the front seatbacks closest to
the door. For vehicles with roof-rail
airbags, there are airbag modules
in the ceiling of the vehicle, near the
side windows that have occupant
seating positions.
How Does an Airbag
Restrain?
In moderate to severe frontal or
near frontal collisions, even belted
occupants can contact the steering
wheel or the instrument panel.
In moderate to severe side
collisions, even belted occupants
can contact the inside of the vehicle.
Airbags supplement the protection
provided by safety belts.
Frontal airbags distribute the force
of the impact more evenly over
the occupant’s upper body, stopping
the occupant more gradually.
Seat-mounted side impact and
roof-rail airbags distribute the force
of the impact more evenly over
the occupant’s upper body.
Seats and Restraint System 1-53

The following describes how the URPA display lights appear as the vehicle
gets closer to a detected object:
DescriptionEnglishMetric
amber light 8 ft2.5 m
amber/amber lights 40 in1.0 m
amber/amber/red lights 23 in0.6 m
amber/amber/red lights ashing 1 ft 0.3 m
The system can be disabled through
the Driver Information Center
(DIC). See “Park Assist” under DIC
Operation and Displays (With
DIC Buttons) on page 3-46 orDIC
Operation and Displays (Without
DIC Buttons) on page 3-51 for more
information.
When the System Does Not
Seem to Work Properly
If the URPA system will not activate
due to a temporary condition, the
message PARK ASSIST OFF will be
displayed on the DIC and a red
light will be shown on the rear URPA display when the shift lever is
moved into R (Reverse). This may
occur under the following
conditions:
The driver disables the system.
The parking brake pedal is
depressed.
The ultrasonic sensors are not
clean. Keep the vehicle’s rear
bumper free of mud, dirt,
snow, ice and slush. For cleaning
instructions, see
Washing Your
Vehicle on page 5-84 .
A trailer was attached to the
vehicle, or a bicycle or an
object was hanging out of the
liftgate during the last drive cycle,
the red light may illuminate in
the rear display. Once the
attached object is removed,
URPA will return to normal
operation.
A tow bar is attached to the
vehicle.
The vehicle’s bumper is
damaged. Take the vehicle to
your dealer/retailer to repair
the system.
Other conditions may affect
system performance, such
as vibrations from a jackhammer
or the compression of air
brakes on a very large truck.
If the system is still disabled, after
driving forward at least 15 mph
(25 km/h), take the vehicle to your
dealer/retailer.
2-36 Features and Controls

Steering
Power Steering
If power steering assist is lost
because the engine stops or the
system is not functioning, the vehicle
can be steered but it will take
more effort.
Variable Effort Steering
If the vehicle has this steering
system, the system continuously
adjusts the effort felt when steering
at all vehicle speeds. It provides
ease when parking, yet a rm, 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.
Steering in Emergencies
There are times when steering can
be more effective than braking.
For example, you come over a hill
and nd a truck stopped in your
lane, or a car suddenly pulls
out from nowhere, or a child darts
out from between parked cars
and stops right in front of you.
These problems can be avoided
by braking — if you can stop in time.
But sometimes you cannot stop in
time because there is no room.
That is the time for evasive
action — steering around the
problem.The vehicle can perform very well in
emergencies like these. First,
apply the brakes. SeeBraking on
page 4-3. It is better to remove
as much speed as possible from a
collision. Then steer around the
problem, to the left or right
depending on the space available.
An emergency like this requires
close attention and a quick decision.
If holding the steering wheel at
the recommended 9 and 3 o’clock
positions, it can be turned a
full 180 degrees very quickly
without removing either hand.
4-8 Driving Your Vehicle

The maximum trailer would only be
7,800 lbs (3 538 kg). You may
go further and think the tongue
weight should be limited to less
than 1,000 lbs (454 kg) to avoid
exceeding GVWR. But the effect
on the rear axle must still be
considered. Because the rear axle
now weighs 3,100 lbs (1 406 kg),
900 lbs (408 kg) can be put on
the rear axle without exceeding
RGAWR. The effect of tongue
weight is about 1.5 times the
actual weight. Dividing the 900 lbs
(408 kg) by 1.5 leaves only
600 lbs (272 kg) of tongue weight
that can be handled. Since
tongue weight is usually at least
10 percent of total loaded trailer
weight, expect that the largest
trailer the vehicle can properly
handle is 6,000 lbs (2 721 kg).It is important that the vehicle
does not exceed any of its
ratings —GCWR, GVWR, RGAWR,
Maximum Trailer Rating or Tongue
Weight. The only way to be sure it is
not exceeding any of these ratings is
to weigh the vehicle and trailer.
Total Weight on the
Vehicle’s Tires
Be sure the vehicle’s tires are
inated to the upper limit for cold
tires. These numbers can be found
on the Certication/Tire label.
SeeLoading the Vehicle on
page 4-16. Make sure not to go
over the GVW limit for the vehicle,
including the weight of the trailer
tongue.
Hitches
It is important to have the correct
hitch equipment. Crosswinds,
large trucks going by and rough
roads are a few reasons why
the right hitch is needed. Here
are some rules to follow:
The rear bumper on the vehicle
is not intended for hitches. Do
not attach rental hitches or other
bumper-type hitches to it. Use
only a frame-mounted hitch
that does not attach to the
bumper.
Will any holes be made in the
body of the vehicle when the
trailer hitch is installed? If there
are, then be sure to seal the
holes later when the hitch
is removed. If the holes are not
sealed, dirt, water, and deadly
carbon monoxide (CO) from
the exhaust can get into
the vehicle. SeeEngine
Exhaust on page 2-30.
4-28 Driving Your Vehicle

Bead:The tire bead contains
steel wires wrapped by steel
cords that hold the tire onto
the rim.
Bias Ply Tire
:A pneumatic tire
in which the plies are laid at
alternate angles less than
90 degrees to the centerline
of the tread.
Cold Tire Pressure
:The
amount of air pressure in a tire,
measured in pounds per square
inch (psi) or kilopascals (kPa)
before a tire has built up heat
from driving. SeeInflation - Tire
Pressure on page 5-41.
Curb Weight
:The weight of a
motor vehicle with standard
and optional equipment including
the maximum capacity of fuel,
oil, and coolant, but without
passengers and cargo.
DOT Markings
:A code
molded into the sidewall of a
tire signifying that the tire is in
compliance with the U.S.Department of Transportation
(DOT) motor vehicle safety
standards. The DOT code
includes the Tire Identication
Number (TIN), an alphanumeric
designator which can also
identify the tire manufacturer,
production plant, brand, and
date of production.
GVWR
:Gross Vehicle Weight
Rating. SeeLoading the Vehicle
on page 4-16.
GAWR FRT
:Gross Axle
Weight Rating for the front axle.
SeeLoading the Vehicle on
page 4-16.
GAWR RR
:Gross Axle
Weight Rating for the rear axle.
SeeLoading the Vehicle on
page 4-16.
Intended Outboard Sidewall
:The side of an asymmetrical tire,
that must always face outward
when mounted on a vehicle.
Kilopascal (kPa)
:The metric
unit for air pressure.Light Truck (LT-Metric) Tire
:A tire used on light duty
trucks and some multipurpose
passenger vehicles.
Load Index
:An assigned
number ranging from 1 to 279
that corresponds to the load
carrying capacity of a tire.
Maximum Ination Pressure
:The maximum air pressure
to which a cold tire can
be inated. The maximum air
pressure is molded onto the
sidewall.
Maximum Load Rating
:The load rating for a tire at
the maximum permissible
ination pressure for that tire.
Maximum Loaded Vehicle
Weight
:The sum of curb
weight, accessory weight,
vehicle capacity weight, and
production options weight.
Service and Appearance Care 5-39

Normal Occupant Weight:The
number of occupants a vehicle
is designed to seat multiplied by
150 lbs (68 kg). SeeLoading
the Vehicle on page 4-16.
Occupant Distribution
:Designated seating positions.
Outward Facing Sidewall
:The side of an asymmetrical tire
that has a particular side that
faces outward when mounted on
a vehicle. The side of the tire
that contains a whitewall, bears
white lettering, or bears
manufacturer, brand, and/or
model name molding that
is higher or deeper than the
same moldings on the
other sidewall of the tire.
Passenger (P-Metric) Tire
:A tire used on passenger
cars and some light duty trucks
and multipurpose vehicles.Recommended Ination
Pressure
:Vehicle
manufacturer’s recommended
tire ination pressure as
shown on the tire placard.
SeeInflation - Tire Pressure
on page 5-41andLoading the
Vehicle on page 4-16.
Radial Ply Tire
:A pneumatic
tire in which the ply cords
that extend to the beads are
laid at 90 degrees to the
centerline of the tread.
Rim
:A metal support for a
tire and upon which the
tire beads are seated.
Sidewall
:The portion of a tire
between the tread and the bead.
Speed Rating
:An alphanumeric
code assigned to a tire indicating
the maximum speed at which a
tire can operate.Traction
:The friction between
the tire and the road surface.
The amount of grip provided.
Tread
:The portion of a tire that
comes into contact with the road.
Treadwear Indicators
:Narrow
bands, sometimes called wear
bars, that show across the tread
of a tire when only 1/16 inch
(1.6 mm) of tread remains.
SeeWhen It Is Time for New
Tires on page 5-48.
UTQGS (Uniform Tire Quality
Grading Standards)
:A tire
information system that provides
consumers with ratings for a
tire’s traction, temperature,
and treadwear. Ratings are
determined by tire manufacturers
using government testing
procedures. The ratings are
molded into the sidewall of the
tire. SeeUniform Tire Quality
Grading on page 5-51.
5-40 Service and Appearance Care

Additionally, if your vehicle has
electronic systems such as anti-lock
brakes, rollover airbags, traction
control, and electronic stability
control, the performance of these
systems can be affected.
{CAUTION
If you add different sized wheels,
your vehicle may not provide an
acceptable level of performance
and safety if tires not
recommended for those wheels
are selected. You may increase
the chance that you will crash and
suffer serious injury. Only use GM
specic wheel and tire systems
developed for your vehicle, and
have them properly installed by
a GM certied technician.
SeeBuying New Tires on page 5-49
andAccessories and Modifications
on page 5-3for additional
information.
Uniform Tire Quality
Grading
Quality grades can be found
where applicable on the tire
sidewall between tread shoulder
and maximum section width.
For example:
Treadwear 200 Traction AA
Temperature A
The following information relates
to the system developed by the
United States National Highway
Traffic Safety Administration
(NHTSA), which grades tires
by treadwear, traction, and
temperature performance. This
applies only to vehicles sold in
the United States. The grades
are molded on the sidewalls of
most passenger car tires. The
Uniform Tire Quality Grading
(UTQG) system does not apply
to deep tread, winter-type snow
tires, space-saver, or temporary
use spare tires, tires with nominalrim diameters of 10 to 12 inches
(25 to 30 cm), or to some
limited-production tires.
While the tires available on
General Motors passenger cars
and light trucks may vary with
respect to these grades, they
must also conform to federal
safety requirements and
additional General Motors Tire
Performance Criteria (TPC)
standards.
Treadwear
The treadwear grade is a
comparative rating based on the
wear rate of the tire when tested
under controlled conditions on
a specied government test
course. For example, a tire
graded 150 would wear one
and a half (1.5) times as well
on the government course as a
tire graded 100. The relative
performance of tires depends
upon the actual conditions of
their use, however, and may
depart signicantly from the
Service and Appearance Care 5-51

If a Crash Occurs
Here is what to do if you are
involved in a crash.
Check to make sure that you are
all right. If you are uninjured,
make sure that no one else in
your vehicle, or the other vehicle,
is injured.
If there has been an injury, call
emergency services for help. Do
not leave the scene of a crash
until all matters have been taken
care of. Move your vehicle only if
its position puts you in danger or
you are instructed to move it by a
police officer.
Give only the necessary and
requested information to police
and other parties involved in the
crash. Do not discuss your
personal condition, mental frame
of mind, or anything unrelated to
the crash. This will help guard
against post-crash legal action.
If you need roadside assistance,
call GM Roadside Assistance.
SeeRoadside Assistance
Program on page 7-6for more
information.
If your vehicle cannot be driven,
know where the towing service
will be taking it. Get a card from
the tow truck operator or write
down the driver’s name, the
service’s name, and the phone
number.
Remove any valuables from your
vehicle before it is towed away.
Make sure this includes your
insurance information and
registration if you keep these
items in your vehicle.
Gather the important information
you will need from the other
driver. Things like name, address,
phone number, driver’s license
number, vehicle license plate,
vehicle make, model and model
year, Vehicle Identication
Number (VIN), insurance
company and policy number, and
a general description of the
damage to the other vehicle.
If possible, call your insurance
company from the scene of the
crash. They will walk you through
the information they will need. If
they ask for a police report, phone
or go to the police department
headquarters the next day and
you can get a copy of the report
for a nominal fee. In some
states/provinces with “no fault”
insurance laws, a report may not
be necessary. This is especially
true if there are no injuries and
both vehicles are driveable.
7-12 Customer Assistance Information