2010 GMC ACADIA transmission

9-46 Driving and Operating
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.
.Improve control of vehicle speed
while requiring less throttle pedal
activity.
.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 comes 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
Trailer Towing
on page 9‑49.
Tow/Haul is most useful when
pulling a heavy trailer or a large or
heavy load under the following
driving conditions:
.Travelling through rolling terrain.
.Travelling in stop and go traffic.
.Travelling 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
will not cause damage but there is
no benefit. Such a selection when
unloaded may result in unpleasant
engine and transmission driving
characteristics and reduced fuel
economy.

Driving and Operating 9-47
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid situations
that require heavy braking and
sudden turns.
Passing
More passing distance is needed
when towing a trailer. Because the
rig is longer, it is necessary to go
farther beyond the passed vehicle
before returning to the lane.
Backing Up
Hold the bottom of the steering
wheel with one hand. 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 so the
trailer will not strike soft shoulders,
curbs, road signs, trees or other
objects. Use the turn signal well in
advance and avoid jerky or sudden
maneuvers.
Turn Signals When Towing a
Trailer
The turn signal indicators on the
instrument panel flash whenever
signaling a turn or lane change. Properly hooked up, the trailer
lamps also flash, telling other
drivers the vehicle is turning,
changing lanes or stopping.
When towing a trailer, the arrows on
the instrument panel flash for turns
even if the bulbs on the trailer are
burned out. Check occasionally to
be sure the trailer bulbs are still
working.
Driving On Grades
Reduce speed and shift to a lower
gear before starting 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.

9-48 Driving and Operating
The vehicle can tow in D (Drive).
Use a lower gear if the transmission
shifts too often.
When towing at high altitude on
steep uphill grades, engine coolant
will boil at a lower temperature than
at normal altitudes. If the engine is
turned off immediately after towing
at high altitude on steep uphill
grades, the vehicle may show
signs similar to engine overheating.
To avoid this, 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. If the
overheat warning comes on, see
Engine Overheating on page 10‑19.
On a long uphill grade, shift down
and reduce the vehicle speed to
around 88 km/h (55 mph) to reduce
the possibility of the engine and the
transmission overheating.Parking on Hills
{WARNING
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 flat 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
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.
.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.

Driving and Operating 9-49
Maintenance When Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See this
manual's Maintenance Schedule or
Index for more information. 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. SeeEngine Overheating
on page 10‑19.
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.

Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-3
California Proposition 65Warning . . . . . . . . . . . . . . . . . . . . 10-3
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-4
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-6
Engine Cover . . . . . . . . . . . . . . . . 10-7 Engine Oil . . . . . . . . . . . . . . . . . . . 10-8
Engine Oil Life System . . . . . 10-10
Automatic Transmission
Fluid . . . . . . . . . . . . . . . . . . . . . . 10-11
Engine Air Cleaner/Filter . . . . 10-12
Cooling System . . . . . . . . . . . . 10-14
Engine Coolant . . . . . . . . . . . . . 10-14
Engine Overheating . . . . . . . . 10-19
Overheated Engine
Protection
Operating Mode . . . . . . . . . . . 10-21
Power Steering Fluid . . . . . . . 10-21
Washer Fluid . . . . . . . . . . . . . . . 10-22
Brakes . . . . . . . . . . . . . . . . . . . . . 10-23
Brake Fluid . . . . . . . . . . . . . . . . . 10-24
Battery . . . . . . . . . . . . . . . . . . . . . 10-25
All-Wheel Drive . . . . . . . . . . . . . 10-26
Starter Switch Check . . . . . . . 10-26
Automatic Transmission Shift Lock Control System
Check . . . . . . . . . . . . . . . . . . . . . 10-26 Ignition Transmission Lock
Check . . . . . . . . . . . . . . . . . . . . . 10-27
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-27
Wiper Blade
Replacement . . . . . . . . . . . . . . 10-27
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-28
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-29
Halogen Bulbs . . . . . . . . . . . . . . 10-29
License Plate Lamp . . . . . . . . 10-29
Replacement Bulbs . . . . . . . . . 10-29
Electrical System
High Voltage Devices andWiring . . . . . . . . . . . . . . . . . . . . . 10-30
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-30

Vehicle Care 10-7
A. Radiator Pressure Cap . SeeCooling System on page 10‑14.
B. Engine Coolant Recovery Cap. See Cooling System
on
page 10‑14.
C. Remote Negative (−) Terminal. See Jump Starting
on
page 10‑78.
D. Engine Compartment Fuse
Block on page 10‑31.
E. Remote Positive (+) Terminal. See Jump Starting
on
page 10‑78.
F. Power Steering Reservoir and Cap (under engine cover). See
Power Steering Fluid
on
page 10‑21.
G. Engine Oil Fill Cap. See “When
to Add Engine Oil” underEngine
Oil on page 10‑8. H.
Engine Cover on page 10‑7.
I. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil on page 10‑8.
J. Automatic Transmission Fluid Dipstick. See “Checking the
Fluid Level” underAutomatic
Transmission Fluid
on
page 10‑11.
K. Brake Master Cylinder Reservoir. See “Brake Fluid”
under Brakes on page 10‑23.
L. Engine Air Cleaner/Filter
on
page 10‑12.
M. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid
on
page 10‑22.
Engine Cover
A. Oil Fill Cap
B. Engine Cover
To remove:
1. Remove the oil fill cap (A).
2. Raise the engine cover (B) to release from the retainers.
3. Lift and remove the engine cover.
4. Reverse Steps 1 through 3 to reinstall engine cover.

Vehicle Care 10-11
2. Press and hold the trip odometerreset stem until OIL LIFE
REMAINING shows 100%.
Three chimes sound and the
CHANGE ENGINE OIL SOON
message goes off.
3. Turn the key to LOCK/OFF. If the CHANGE ENGINE OIL
SOON message comes back on
when the vehicle is started, the
engine oil life system has not
reset. Repeat the procedure.
If the vehicle has Driver Information
Center (DIC) buttons:
1. Turn the ignition to ON/RUN, with the engine off.
2. Press the vehicle information button until OIL LIFE
REMAINING displays. 3. Press and hold the set/reset
button until 100% is displayed.
Three chimes sound and the
CHANGE ENGINE OIL SOON
message goes off.
4. Turn the key to LOCK/OFF.
If the CHANGE ENGINE OIL SOON
message comes back on when the
vehicle is started, the engine oil life
system has not reset. Repeat the
procedure.
What to Do with Used Oil
Used engine oil contains certain
elements that can be unhealthy for
your skin and could even cause
cancer. Do not let used oil stay on
your skin for very long. Clean your
skin and nails with soap and water,
or a good hand cleaner. Wash or
properly dispose of clothing or rags
containing used engine oil. See the
manufacturer's warnings about the
use and disposal of oil products. Used oil can be a threat to the
environment. If you change your
own oil, be sure to drain all the oil
from the filter before disposal. Never
dispose of oil by putting it in the
trash, pouring it on the ground, into
sewers, or into streams or bodies of
water. Recycle it by taking it to a
place that collects used oil.
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/retailer and have it repaired
as soon as possible.

10-12 Vehicle Care
Change the fluid at the intervals
listed inScheduled Maintenanceon
page 11‑2, and be sure to use the
transmission fluid listed in
Recommended Fluids and
Lubricants on page 11‑8.
Notice: Use of the incorrect
automatic transmission fluid may
damage the vehicle, and the
damages may not be covered by
the vehicle's warranty. Always
use the automatic transmission
fluid listed in Recommended
Fluids and Lubricants
on
page 11‑8.
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/
retailer.
Engine Air Cleaner/Filter
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter at the
Maintenance IIintervals and replace
it at the first oil change after each
80 000 km (50,000 mile) interval.
See Scheduled Maintenance
on
page 11‑2for more information.
If driving in dusty/dirty conditions,
inspect the filter at each engine oil
change.
See Engine Compartment Overview
on page 10‑6for 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 caked
with dirt, a new filter is required. To inspect or replace the engine air
cleaner/filter, do the following:
1. Remove the engine cover. See
Engine Cover on page 10‑7.
A. Ventilation Tube
B. Sensor
2. Disconnect the cover fitting from the ventilation tube (A).
3. Disconnect the wiring harness connector from the sensor (B).