engine GMC ACADIA 2009 Repair Manual

Towing a Trailer
{CAUTION
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly.
For example, if the trailer is too
heavy, the brakes may not work
well — or even at all. The driver
and passengers could be
seriously injured. The vehicle may
also be damaged; the resulting
repairs would not be covered by
the vehicle warranty. Pull a trailer
only if all the steps in this section
have been followed. Ask your
dealer/retailer for advice and
information about towing a trailer
with the vehicle.
To identify the trailering capacity of
the vehicle, read the information
in “Weight of the Trailer” that
appears later in this section.Trailering is different than just
driving the vehicle by itself.
Trailering means changes in
handling, acceleration, braking,
durability and fuel economy.
Successful, safe trailering takes
correct equipment, and it has to be
used properly.
The following information has many
time-tested, important trailering
tips and safety rules. Many of these
are important for the safety of the
driver and the passengers. So
please read this section carefully
before pulling a trailer.
Load-pulling components such as
the engine, transmission, rear
axle, wheel assemblies and tires are
forced to work harder against the
drag of the added weight. The
engine is required to operate
at relatively higher speeds and
under greater loads, generating
extra heat. What’s more, the trailer
adds considerably to wind
resistance, increasing the pulling
requirements.
Pulling A Trailer
Here are some important points:
There are many different
laws, including speed limit
restrictions, having to do with
trailering. Make sure the rig will
be legal, not only where you
live but also where you will be
driving. A good source for
this information can be state or
provincial police.
Consider using a sway control.
See “Hitches” later in this section.
Do not tow a trailer at all during
the rst 500 miles (800 km) the
new vehicle is driven. The engine,
axle or other parts could be
damaged.
Then, during the rst 500 miles
(800 km) that a trailer is towed, do
not drive over 50 mph (80 km/h)
and do not make starts at full
throttle. This helps the engine and
other parts of the vehicle wear in
at the heavier loads.
4-24 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

Backing Up
Hold the bottom of the steering
wheel with one hand. Then, to move
the trailer to the left, move that
hand to the left. To move the trailer
to the right, move your hand to
the right. Always back up slowly
and, if possible, have someone
guide you.
Making Turns
Notice:Making very sharp turns
while trailering could cause
the trailer to come in contact with
the vehicle. The vehicle could
be damaged. Avoid making very
sharp turns while trailering.
When turning with a trailer, make
wider turns than normal. Do this so
the trailer won’t strike soft shoulders,
curbs, road signs, trees or other
objects. Avoid jerky or sudden
maneuvers. Signal well in advance.
Turn Signals When Towing a
Trailer
The arrows on the instrument panel
ash whenever signaling a turn
or lane change. Properly hooked up,
the trailer lamps also ash, telling
other drivers the vehicle is turning,
changing lanes or stopping.
When towing a trailer, the arrows on
the instrument panel ash for turns
even if the bulbs on the trailer are
burned out. For this reason you may
think other drivers are seeing the
signal when they are not. It is
important to check occasionally to be
sure the trailer bulbs are still working.
Driving on Grades
Because of the added load of the
trailer, the vehicle’s engine may
overheat on hot days, when going
up a long or steep grade with a
trailer. If the engine coolant
temperature gage indicates
overheating, turn off the air
conditioning to reduce engine load,
pull off the road and stop in a
safe spot. Let the engine run while
parked, preferably on level
ground, with the transmission in
P (Park) for a few minutes before
turning the engine off.
Reduce speed and shift to a lower
gearbeforestarting down a long
or steep downgrade. If the
transmission is not shifted down, the
brakes might have to be used so
much that they would get hot and no
longer work well.
On a long uphill grade, shift down
and reduce the vehicle speed
to around 55 mph (88 km/h) to
reduce the possibility of the engine
and the transmission overheating.
4-30 Driving Your Vehicle

Tow/Haul Mode
Tow/Haul is a feature that 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 when pulling
a heavy trailer or a large or
heavy load.
Provide the same solid shift feel
when pulling a heavy trailer or a
large or heavy load as when
the vehicle is unloaded.
Improve control of vehicle speed
while requiring less throttle pedal
activity when pulling a heavy
trailer or a large or heavy load.
Increase the charging system
voltage to assist in recharging
a battery installed in a trailer.Press this button located on the
console to turn on and turn off the
Tow/Haul mode.
The Tow/Haul light on the
instrument panel will come on to
indicate that Tow/Haul mode
has been selected.
Tow/Haul may be turned off by
pressing the button again, at which
time the indicator light on the
instrument panel will turn off. The
vehicle will automatically turn
off Tow/Haul every time it is started.
Tow/Haul is designed to be most
effective when the vehicle and
trailer combined weight is at
least 75 percent of the vehicle’s
Gross Combined Weight Rating
(GCWR). See Weight of the Trailerearlier in this section. Tow/Haul is
most useful under the following
driving conditions:
When pulling a heavy trailer or a
large or heavy load through
rolling terrain.
When pulling a heavy trailer or a
large or heavy load in stop and
go traffic.
When pulling a heavy trailer or a
large or heavy load in busy
parking lots where improved low
speed control of the vehicle is
desired.
Operating the vehicle in Tow/Haul
when lightly loaded or with no trailer
at all will not cause damage.
However, there is no benet to the
selection of Tow/Haul when the
vehicle is unloaded. Such a selection
when unloaded may result in
unpleasant engine and transmission
driving characteristics and reduced
fuel economy. Tow/Haul is
recommended only when pulling a
heavy trailer or a large or heavy load.
Driving Your Vehicle 4-31

Parking on Hills
{CAUTION
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a at surface.
If parking the rig on a hill:
1. Press the brake pedal, but do
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 the transmission into
P (Park).
5. Release the brake pedal.
Leaving After Parking
on a Hill
1. Apply and hold the brake pedal
while you:
start the engine,
shift into a gear, and
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.
SeeScheduled Maintenance on
page 6-3for more information.
Things that are especially important
in trailer operation are automatic
transmission uid, engine oil,
axle lubricant, belts, cooling system
and brake system. It is a good
idea to inspect these before and
during the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Trailer Wiring Harness
The vehicle is equipped with the
following wiring harness for towing
a trailer.
4-32 Driving Your Vehicle

Basic Trailer Wiring
The trailer wiring harness, with a
seven-pin connector, is located
at the rear of the vehicle and is
tied to the vehicle’s frame.
The harness connector can be
plugged into a seven-pin universal
heavy-duty trailer connector
available through your
dealer/retailer.
The seven-wire harness contains
the following trailer circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn
Signal
Brown: Taillamps
Black: Ground
Light Green: Back-up Lamps
Red/Black: Battery Feed
Dark Blue: Trailer Brake*
*The fuse for this circuit is installed
in the underhood electrical center,
but the wires are not connected.
They should be connected by your
dealer/retailer or a qualied
service center.
If the back-up lamp circuit is not
functional, contact your
dealer/retailer.If a remote (non-vehicle) battery is
being charged, press the Tow/Haul
mode switch located on the center
console near the climate controls.
This will boost the vehicle system
voltage and properly charge the
battery. If the trailer is too light for
Tow/Haul mode, turn on the
headlamps (Non-HID only) as a
second way to boost the vehicle
system and charge the battery.
Engine Cooling When Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. SeeEngine Overheating
on page 5-21.
Driving Your Vehicle 4-33

Service and
Appearance Care
Service
Service...............................5-3
Accessories and
Modications.....................5-3
California Proposition 65
Warning............................5-3
California Perchlorate
Materials Requirements.....5-3
Doing Your Own
Service Work....................5-4
Adding Equipment to the
Outside of the Vehicle......5-4
Fuel
Fuel....................................5-5
Gasoline Octane.................5-5
Gasoline Specications.......5-5
California Fuel....................5-5
Additives.............................5-5
Fuels in Foreign
Countries..........................5-6
Filling the Tank...................5-7
Filling a Portable Fuel
Container..........................5-8
Checking Things
Under the Hood
Checking Things Under
the Hood..........................5-9
Hood Release.....................5-9
Engine Compartment
Overview.........................5-10
Engine Oil.........................5-11
Engine Oil Life System.....5-13
Engine Air Cleaner/Filter. . .5-15
Automatic Transmission
Fluid................................5-16
Cooling System.................5-16
Engine Coolant.................5-17
Engine Overheating...........5-21
Overheated Engine
Protection
Operating Mode
...............5-23
Power Steering Fluid.........5-23
Windshield Washer Fluid. . .5-24
Brakes..............................5-25
Battery..............................5-28
Jump Starting...................5-28
All-Wheel Drive
All-Wheel Drive.................5-33
Headlamp Aiming
Headlamp Aiming..............5-33
Bulb Replacement
Bulb Replacement.............5-33
Halogen Bulbs..................5-33
License Plate Lamp..........5-34
Replacement Bulbs...........5-34
Windshield Wiper
Blade Replacement
Windshield Wiper Blade
Replacement...................5-34
Tires
Tires.................................5-35
Tire Sidewall Labeling.......5-36
Tire Terminology and
Denitions.......................5-38
Ination - Tire Pressure. . . .5-41
Tire Pressure Monitor
System............................5-42
Tire Pressure Monitor
Operation........................5-44
Tire Inspection and
Rotation..........................5-47
Service and Appearance Care 5-1

Service
For service and parts needs, visit
your dealer/retailer. You will receive
genuine GM parts and GM-trained
and supported service people.
Genuine GM parts have one
of these marks:
Accessories and
Modications
When non-dealer/non-retailer
accessories are added to the
vehicle, they can affect vehicleperformance and safety, including
such things as airbags, braking,
stability, ride and handling,
emissions systems, aerodynamics,
durability, and electronic systems
like antilock brakes, traction control,
and stability control. Some of
these accessories could even
cause malfunction or damage not
covered by the vehicle warranty.
GM Accessories are designed to
complement and function with other
systems on the vehicle. Your GM
dealer/retailer can accessorize
the vehicle using genuine GM
Accessories. When you go to your
GM dealer/retailer and ask for GM
Accessories, you will know that
GM-trained and supported service
technicians will perform the work
using genuine GM Accessories.
Also, seeAdding Equipment to
Your Airbag-Equipped Vehicle on
page 1-60.
California Proposition 65
Warning
Most motor vehicles, including this
one, contain and/or emit chemicals
known to the State of California to
cause cancer and birth defects
or other reproductive harm. Engine
exhaust, many parts and systems
(including some inside the vehicle),
many uids, and some component
wear by-products contain and/or
emit these chemicals.
California Perchlorate
Materials Requirements
Certain types of automotive
applications, such as airbag
initiators, seat belt pretensioners,
and lithium batteries contained
in remote keyless transmitters,
may contain perchlorate materials.
Special handling may be necessary.
For additional information, see
www.dtsc.ca.gov/hazardouswaste/
perchlorate.
Service and Appearance Care 5-3

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.
Gasoline Octane
Use regular unleaded gasoline with
a posted octane rating of 87 or
higher. If the octane rating is less
than 87, you might notice an audible
knocking noise when you drive,
commonly referred to as spark
knock. If this occurs, use a gasoline
rated at 87 octane or higher as
soon as possible. If you are using
gasoline rated at 87 octane or higher
and you hear heavy knocking, the
engine needs service.
Gasoline Specications
At a minimum, gasoline
should meet ASTM specication
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. SeeAdditives on
page 5-5for additional information.
California Fuel
If the vehicle is certied to meet
California Emissions Standards,
it is designed to operate on fuels
that meet California specications.
See the underhood emission control
label. If this fuel is not available in
states adopting California emissions
standards, the vehicle will operate
satisfactorily on fuels meeting federal
specications, but emission controlsystem performance might be
affected. The malfunction indicator
lamp could turn on and the vehicle
might fail a smog-check test. See
Malfunction Indicator Lamp on
page 3-41. If this occurs, return to
your authorized dealer/retailer for
diagnosis. If it is determined that the
condition is caused by the type of
fuel used, repairs might not be
covered by the vehicle warranty.
Additives
To provide cleaner air, all gasolines
in the United States are now required
to contain additives that help prevent
engine and fuel system deposits
from forming, allowing the emission
control system to work properly.
In most cases, you should not have
to add anything to the fuel. However,
some gasolines contain only the
minimum amount of additive required
to meet U.S. Environmental
Protection Agency regulations.
Service and Appearance Care 5-5

Filling the Tank
{CAUTION
Fuel vapor burns violently and a
fuel re can cause bad injuries.
To help avoid injuries to you and
others, read and follow all the
instructions on the pump island.
Turn off the engine when you are
refueling. Do not smoke if you are
near fuel or refueling the vehicle.
Do not use cellular phones. Keep
sparks, ames, and smoking
materials away from fuel. Do not
leave the fuel pump unattended
when refueling the vehicle. This is
against the law in some places.
Do not re-enter the vehicle while
pumping fuel. Keep children away
from the fuel pump; never let
children pump fuel.
The tethered fuel cap is located
behind a hinged fuel door on
the driver side of the vehicle.To open the fuel door, push the
rearward center edge in and release
and it will open.
To remove the fuel cap, turn it
slowly counterclockwise. The fuel
cap has a spring in it; if the cap
is released too soon, it will spring
back to the right.
While refueling, hang the tethered
fuel cap from the hook on the
fuel door.
{CAUTION
Fuel can spray out on you if you
open the fuel cap too quickly. If
you spill fuel and then something
ignites it, you could be badly
burned. This spray can happen if
the tank is nearly full, and is more
likely in hot weather. Open the
fuel cap slowly and wait for any
hiss noise to stop. Then unscrew
the cap all the way.
Be careful not to spill fuel. Do not top
off or overll the tank and wait a few
seconds after you have nished
pumping before removing the nozzle.
Clean fuel from painted surfaces as
soon as possible. SeeWashing Your
Vehicle on page 5-84.
When replacing the fuel cap, turn
it clockwise until it clicks. Make
sure the cap is fully installed.
The diagnostic system can
determine if the fuel cap has
been left off or improperly installed.
Service and Appearance Care 5-7