2008 GMC ACADIA wheel size

Adding Equipment to Your
Airbag-Equipped Vehicle
Q:Is there anything I might add to or change
about the vehicle that could keep the airbags
from working properly?
A:Yes. If you add things that change your vehicle’s
frame, bumper system, height, front end or side
sheet metal, they may keep the airbag system from
working properly. Changing or moving any parts
of the front seats, safety belts, the airbag sensing
and diagnostic module, steering wheel, instrument
panel, roof-rail airbag modules, ceiling headliner
or pillar garnish trim, front sensors, side impact
sensors, rollover sensor module, or airbag wiring
can affect the operation of the airbag system.
In addition, your vehicle has a passenger sensing
system for the right front passenger’s position,
which includes sensors that are part of the
passenger’s seat. The passenger sensing system
may not operate properly if the original seattrim is replaced with non-GM covers, upholstery or
trim, or with GM covers, upholstery or trim
designed for a different vehicle. Any object, such as
an aftermarket seat heater or a comfort enhancing
pad or device, installed under or on top of the
seat fabric, could also interfere with the operation of
the passenger sensing system. This could either
prevent proper deployment of the passenger
airbag(s) or prevent the passenger sensing system
from properly turning off the passenger airbag(s).
SeePassenger Sensing System on page 1-70.
If you have any questions about this, you should
contact Customer Assistance before you modify
your vehicle. The phone numbers and addresses for
Customer Assistance are in Step Two of the
Customer Satisfaction Procedure in this manual.
SeeCustomer Satisfaction Procedure on page 7-2.
If your vehicle has rollover roof-rail airbags, see
Different Size Tires and Wheels on page 5-66
for additional important information.
1-76

DIC Warnings and Messages
Messages are displayed on the DIC to notify the driver
that the status of the vehicle has changed and that
some action may be needed by the driver to correct
the condition. Multiple messages may appear one after
another.
Some messages may not require immediate action,
but you can press any of the DIC buttons on the
instrument panel or the trip odometer reset stem on
the instrument panel cluster to acknowledge that
you received the messages and to clear them from
the display.
Some messages cannot be cleared from the DIC
display because they are more urgent. These messages
require action before they can be cleared. You should
take any messages that appear on the display seriously
and remember that clearing the messages will only
make the messages disappear, not correct the problem.
The following are the possible messages that can be
displayed and some information about them.
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 uid is overheating. This message
turns off when the differential uid 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/retailer right away. SeeAll-Wheel Drive (AWD)
System on page 4-9for more information.
AUTOMATIC LIGHT CONTROL OFF
This message displays when the automatic
headlamps are turned off. This message clears
itself after 10 seconds.
AUTOMATIC LIGHT CONTROL ON
This message displays when the automatic
headlamps are turned on. This message clears
itself after 10 seconds.
3-66

All-Wheel Drive (AWD) System
If your vehicle has this feature, engine power is sent to all
four wheels when extra traction is needed. This is like
four-wheel drive, but there is no separate lever or switch
to engage or disengage the front axle. It is fully automatic,
and adjusts itself as needed for road conditions.
When using a compact spare tire on your AWD
equipped vehicle, the AWD system automatically detects
the presence of the compact spare and the AWD is
disabled. To restore the AWD operation and prevent
excessive wear on the clutch in your AWD system,
replace the compact spare with a full-size tire as soon
as possible. SeeCompact Spare Tire on page 5-88
for more information.
Steering
Power Steering
If you lose power steering assist because the engine
stops or the system is not functioning, you can steer but
it will take much more effort.
Variable Effort Steering
If your vehicle has this steering system, the system
continuously adjusts the effort you feel 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.
A lot of the “driver lost control” accidents mentioned on
the news happen on curves. Here is why:
Experienced driver or beginner, each of us is subject to
the same laws of physics when driving on curves.
The traction of the tires against the road surface makes
it possible for the vehicle to change its path when
you turn the front wheels. If there is no traction, inertia
will keep the vehicle going in the same direction. If
you have ever tried to steer a vehicle on wet ice, you
will understand this.
The traction you can get in a curve depends on the
condition of the tires and the road surface, the angle at
which the curve is banked, and your speed. While
you are in a curve, speed is the one factor you
can control.
Suppose you are steering through a sharp curve.
Then you suddenly accelerate. Both control
systems — steering and acceleration — have to do their
work where the tires meet the road. Adding the
sudden acceleration can demand too much of those
places. You can lose control. SeeStabiliTrak
®System
on page 4-6.
What should you do if this ever happens? Ease up on
the accelerator pedal, steer the vehicle the way you
want it to go, and slow down.
4-9

To tow your vehicle from the front with all four wheels
on the ground:
1. Position the vehicle to tow and then secure it.
2. Turn the ignition to LOCK/OFF.
3. Set the parking brake.
4. Turn the ignition to ACC/ACCESSORY.
5. Shift your transmission to NEUTRAL (N).
6. To prevent your battery from draining while the
vehicle is being towed, disconnect the vehicle’s
battery. Contact your dealer/retailer for more
information on the battery disconnection procedure.
7. Release the parking brake.Notice:If you tow your vehicle without performing
each of the steps listed under “Dinghy Towing,”
you could damage the automatic transmission. Be
sure to follow all steps of the dinghy towing
procedure prior to and after towing your vehicle.
Notice:If you exceed 65 mph (105 km/h) while
towing your vehicle, it could be damaged. Never
exceed 65 mph (105 km/h) while towing your vehicle.
Once you have reached your destination:
1. Set the parking brake.
2. Re-connect the vehicle’s battery. Contact your
dealer/retailer for more information on the battery
connection procedure.
3. Turn the ignition key to LOCK/OFF and remove the
key from the ignition.
Notice:Don’t tow a vehicle with the front drive
wheels on the ground if one of the front tires is a
compact spare tire. Towing with two different
tire sizes on the front of the vehicle can cause
severe damage to the transmission.
4-28

Service............................................................5-3
Accessories and Modications..........................5-4
California Proposition 65 Warning.....................5-4
California Perchlorate Materials Requirements.....5-4
Doing Your Own Service Work.........................5-5
Adding Equipment to the Outside of Your
Vehicle......................................................5-6
Fuel................................................................5-6
Gasoline Octane............................................5-6
Gasoline Specications....................................5-6
California Fuel...............................................5-7
Additives.......................................................5-7
Fuels in Foreign Countries...............................5-8
Filling the Tank..............................................5-9
Filling a Portable Fuel Container.....................5-12
Checking Things Under the Hood....................5-12
Hood Release..............................................5-13
Engine Compartment Overview.......................5-14
Engine Oil...................................................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter................................5-20
Automatic Transmission Fluid.........................5-21
Engine Coolant.............................................5-22
Radiator Pressure Cap..................................5-24
Engine Overheating.......................................5-25
Overheated Engine Protection Operating Mode . . .5-26Cooling System............................................5-27
Power Steering Fluid.....................................5-33
Windshield Washer Fluid................................5-34
Brakes........................................................5-35
Battery........................................................5-38
Jump Starting...............................................5-39
All-Wheel Drive..............................................5-43
Headlamp Aiming...........................................5-45
Bulb Replacement..........................................5-45
Halogen Bulbs..............................................5-45
License Plate Lamp......................................5-46
Replacement Bulbs.......................................5-46
Windshield Wiper Blade Replacement..............5-47
Tires..............................................................5-48
Tire Sidewall Labeling...................................5-49
Tire Terminology and Denitions.....................5-52
Ination - Tire Pressure.................................5-55
Tire Pressure Monitor System.........................5-57
Tire Pressure Monitor Operation.....................5-58
Tire Inspection and Rotation...........................5-62
When It Is Time for New Tires.......................5-63
Buying New Tires.........................................5-64
Different Size Tires and Wheels......................5-66
Uniform Tire Quality Grading..........................5-67
Wheel Alignment and Tire Balance..................5-68
Section 5 Service and Appearance Care
5-1

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
vehicle’s 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 inated to the ination
pressure recommended by the vehicle manufacturer
on the vehicle placard or tire ination pressure label. (If
your vehicle has tires of a different size than the size
indicated on the vehicle placard or tire ination pressure
label, you should determine the proper tire ination
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 tire pressure telltale when one
or more of your tires is signicantly under-inated.
Accordingly, when the low tire pressure telltale
illuminates, you should stop and check your tires as
soon as possible, and inate them to the proper
pressure. Driving on a signicantly under-inated tire
causes the tire to overheat and can lead to tire failure.
Under-ination 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-ination has
not reached the level to trigger illumination of the
TPMS low tire pressure telltale.
Your vehicle has also been equipped with a TPMS
malfunction indicator to indicate when the system is not
operating properly. The TPMS malfunction indicator
is combined with the low tire pressure telltale. When the
system detects a malfunction, the telltale will ash for
approximately one minute and then remain continuously
illuminated. This sequence will continue upon
subsequent vehicle start-ups as long as the malfunction
exists.
When the malfunction indicator is illuminated, the
system may not be able to detect or signal low tire
pressure as intended. TPMS malfunctions may occur for
a variety of reasons, including the installation of
replacement or alternate tires or wheels on the vehicle
that prevent the TPMS from functioning properly.
Always check the TPMS malfunction telltale after
replacing one or more tires or wheels on your vehicle to
ensure that the replacement or alternate tires and
wheels allow the TPMS to continue to function properly.
SeeTire Pressure Monitor Operation on page 5-58,
for additional information.
5-57

GM recommends replacing tires in sets of four.
This is because uniform tread depth on all tires will
help keep your vehicle performing most like it
did when the tires were new. Replacing less than
a full set of tires can affect the braking and
handling performance of your vehicle. SeeTire
Inspection and Rotation on page 5-62for
information on proper tire rotation.
{CAUTION:
Mixing tires could cause you to lose
control while driving. If you mix tires of
different sizes, brands, or types (radial
and bias-belted tires), the vehicle may not
handle properly, and you could have a
crash. Using tires of different sizes,
brands, or types may also cause damage
to your vehicle. Be sure to use the correct
size, brand, and type of tires on all
wheels. It is all right to drive with your
compact spare temporarily, as it was
developed for use on your vehicle. See
Compact Spare Tire on page 5-88.
{CAUTION:
If you use bias-ply tires on your vehicle,
the wheel rim anges could develop
cracks after many miles of driving. A tire
and/or wheel could fail suddenly, causing
a crash. Use only radial-ply tires with the
wheels on your vehicle.
If you must replace your vehicle’s tires with those
that do not have a TPC Spec number, make
sure they are the same size, load range, speed
rating, and construction type (radial and
bias-belted tires) as your vehicle’s original tires.
Vehicles that have a tire pressure monitoring
system could give an inaccurate low-pressure
warning if non-TPC Spec rated tires are installed
on your vehicle. Non-TPC Spec rated tires
may give a low-pressure warning that is higher or
lower than the proper warning level you would
get with TPC Spec rated tires. SeeTire Pressure
Monitor System on page 5-57.
5-65

Your vehicle’s original equipment tires are listed
on the Tire and Loading Information Label.
SeeLoading Your Vehicle on page 4-21, for more
information about the Tire and Loading Information
Label and its location on your vehicle.
Different Size Tires and Wheels
If you add wheels or tires that are a different size than
your original equipment wheels and tires, this could
affect the way your vehicle performs, including its
braking, ride and handling characteristics, stability, and
resistance to rollover. 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 5-64andAccessories
and Modifications on page 5-4for additional information.
5-66