2010 GMC ACADIA ECU

Driving and Operating 9-15
{WARNING
Things you put inside your
vehicle can strike and injure
people in a sudden stop or
turn, or in a crash.
.Put things in the cargo
area of your vehicle. Try to
spread the weight evenly.
.Never stack heavier
things, like suitcases,
inside the vehicle so that
some of them are above
the tops of the seats.
.Do not leave an
unsecured child restraint
in your vehicle.
.When you carry something
inside the vehicle, secure
it whenever you can.
.Do not leave a seat folded
down unless you need to.
Starting and
Operating
New Vehicle Break-In
Notice: The vehicle does not
need an elaborate break-in. But it
will perform better in the long run
if you follow these guidelines:
.If you have all-wheel drive,
keep your speed at 88 km/h
(55 mph) or less for the first
805 km (500 miles).
.Do not drive at any one
constant speed, fast or slow,
for the first 805 km
(500 miles). Do not make
full-throttle starts. Avoid
downshifting to brake or
slow the vehicle.
.Avoid making hard stops for
the first 322 km (200 miles) or
so. During this time the new
brake linings are not yet
broken in. Hard stops with
new linings can mean
premature wear and earlier
replacement. Follow this
breaking-in guideline every
time you get new brake
linings.
.Do not tow a trailer during
break-in. See Driving
Characteristics and Towing
Tips
on page 9‑44for the
trailer towing capabilities of
your vehicle and more
information.
Following break-in, engine speed
and load can be gradually
increased.

Driving and Operating 9-45
The following information has
important trailering tips and rules for
your safety and that of your
passengers. Read this section
carefully before pulling a trailer.
Pulling A Trailer
Here are some important points:
.There are many laws, including
speed limit restrictions that apply
to trailering. Check for legal
requirements with state or
provincial police.
.Consider using sway control.
SeeTowing Equipmenton
page 9‑53.
.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.

10-18 Vehicle Care
3. Keep turning the pressure capslowly and remove it.
4. Fill the radiator to the base of the filler neck with the proper
DEX-COOL coolant mixture.
5. When coolant begins to flow out of the filler neck, reinstall the
pressure cap. Be sure to secure
it tightly.
6. Fill the coolant recovery tank tothe FULL COLD mark.
7. Reinstall the cap on the coolant recovery tank but leave the
radiator pressure cap off.8. Start the engine and let it rununtil the upper radiator hose
feels warm. Any time during this
procedure, watch out for the
engine cooling fan(s).

Vehicle Care 10-19
9. If the coolant level inside theradiator filler neck is low, add
more of the proper DEX-COOL
coolant mixture through the filler
neck until the level is back up to
the base of the filler neck.
Replace the pressure cap. Be
sure to secure it tightly.
Notice: If the pressure cap is not
tightly installed, coolant loss and
possible engine damage may
occur. Be sure the cap is properly
and tightly secured.
Engine Overheating
The vehicle has several indicators
to warn of engine overheating.
There is an engine coolant
temperature gage on the instrument
panel cluster. See Engine Coolant
Temperature Gage on page 5‑13. The vehicle may also display an
ENGINE OVERHEATED IDLE
ENGINE and ENGINE
OVERHEATED STOP ENGINE
message in the Driver Information
Center (DIC). See
Warning Lights,
Gages, and Indicators
on
page 5‑10.
You may decide not to lift the hood
when this warning appears, but
instead get service help right away.
See Roadside Assistance Program
on page 13‑5.
If you do decide to lift the hood ,
make sure the vehicle is parked on
a level surface.
Then check to see if the engine
cooling fans are running. If the
engine is overheating, both fans
should be running. If they are not,
do not continue to run the engine
and have the vehicle serviced. Notice:
Engine damage from
running the engine without
coolant is not covered by the
warranty.
Notice: If the engine catches fire
while driving with no coolant, the
vehicle can be badly damaged.
The costly repairs would not be
covered by the vehicle warranty.
See Overheated Engine
Protection Operating Mode
on
page 10‑21for information on
driving to a safe place in an
emergency.

10-50 Vehicle Care
Make certain that all wheel nuts
are properly tightened. See
“Wheel Nut Torque”under
Capacities and Specifications
on
page 12‑2
.
{WARNING
Rust or dirt on a wheel, or on the
parts to which it is fastened, can
make wheel nuts become loose
after time. The wheel could come
off and cause an accident. When
changing a wheel, remove any
rust or dirt from places where the
wheel attaches to the vehicle. In
an emergency, use a cloth or a
paper towel to do this; but be sure
to use a scraper or wire brush
later, if needed, to get all the rust
or dirt off. See If a Tire Goes Flat
on page 10‑56.
Make sure the spare tire, if the
vehicle has one, is stored
securely. Push, pull, and then try to rotate or turn the tire. If it
moves, tighten the cable. See
Tire Changing
on page 10‑66.
When It Is Time for New
Tires
Various factors, such as
maintenance, temperatures, driving
speeds, vehicle loading, and road
conditions influence when you need
new tires.
One way to tell when it is time for
new tires is to check the treadwear
indicators, which appear when the
tires have only 1.6 mm (1/16 inch) or
less of tread remaining.
The vehicle needs new tires if any
of the following statements are true:
.You can see the indicators at
three or more places around
the tire.
.You can see cord or fabric
showing through the tire's
rubber.
.The tread or sidewall is cracked,
cut, or snagged deep enough to
show cord or fabric.
.The tire has a bump, bulge,
or split.
.The tire has a puncture, cut,
or other damage that cannot be
repaired well because of the size
or location of the damage.

10-68 Vehicle Care
6. Turn the wrench clockwise toraise the cable back up after
removing the spare tire.
Do not store a full-size or a flat
road tire under the vehicle. See
“Storing a Flat or Spare Tire and
Tools” later in this section.
To continue changing the flat tire,
see “Removing the Flat Tire and
Installing the Spare Tire” later in this
section.
If the spare tire will not lower, the
secondary latch could be engaged. Do the following to check the cable:
1. Check under the vehicle to see if
the cable is visible.
2. If it is not visible, see Secondary
Latch System on page 10‑74.
If it is visible, first try to tighten
the cable by turning the lug
wrench clockwise until you hear
two clicks or feel it skip twice.
You cannot over-tighten the
cable.
3. Loosen the cable by turning the wrench counterclockwise three
or four turns.
4. If the spare tire has not lowered, tighten the cable all the way and
then loosen it at least two times.
If the spare tire did lower to the
ground, continue with Step 5
under “Removing the Spare Tire
(Vehicles with the Rear
Convenience Center)” listed
previously. 5. If you still cannot lower the spare
tire to the ground, see
Secondary Latch System
on
page 10‑74.
Removing the Flat Tire and
Installing the Spare Tire
1. Do a safety check before proceeding. See If a Tire Goes
Flat
on page 10‑56for more
information.
2. If the vehicle has a wheel cover, loosen the plastic nut caps with
the wheel wrench. They will not
come off. Then, using the flat
end of the wheel wrench, pry
along the edge of the cover until
it comes off. Be careful; the
edges may be sharp. Do not try
to remove the cover with your
bare hands.
Store the wheel cover securely
in the rear of the vehicle until
you have the flat tire repaired or
replaced.

10-72 Vehicle Care
Storing the Spare Tire
{WARNING
The underbody-mounted spare
tire needs to be stored with the
valve stem pointing down. If the
spare tire is stored with the valve
stem pointing upwards, the
secondary latch will not work
properly and the spare tire could
loosen and suddenly fall from the
vehicle. If this happened when
the vehicle was being driven, the
tire might contact a person or
another vehicle, causing injury
and damage to itself. Be sure the
underbody-mounted spare tire is
stored with the valve stem
pointing down.
{WARNING
Storing a jack, a tire, or other
equipment in the passenger
compartment of the vehicle could
cause injury. In a sudden stop or
collision, loose equipment could
strike someone. Store all these in
the proper place.
To store the spare tire:
1. Lay the compact spare tire near the rear of the vehicle with the
valve stem down.
2. Reinstall the plastic spare tire heat shield on the compact
spare tire.
3. Slide the cable retainer through the center of the wheel and start
to raise the compact spare tire.
Make sure the retainer is fully
seated across the underside of
the wheel. 4. When the compact spare tire is
almost in the stored position,
turn the tire so the valve is
toward the rear of the vehicle.
This position helps when
checking the air pressure in the
compact spare tire.
5. Raise the tire fully against the underside of the vehicle.
Continue turning the lug wrench
until you feel more than two
clicks. This indicates that the
compact spare tire is secure and
the cable is tight. The spare tire
hoist cannot be overtightened.

Vehicle Care 10-73
6. Make sure the tire is storedsecurely. Push, pull (A), and then
try to turn (B) the tire. If the tire
moves, use the lug wrench to
tighten the cable.
Storing the Flat Tire
1. Remove the cable package fromthe jack storage area.
2. Remove the small center cap by tapping the back of the cap with
the extension of the shaft, if the
vehicle has aluminum wheels. 3. Put the flat tire in the rear
storage area with the valve stem
pointing toward the rear of the
vehicle.4. Pull the cable (A) through the
door striker (E), the center of the
wheel (D), and the plastic spare
tire heat shield (C), as shown.
5. Hook the cable onto the outsideportion of the liftgate hinges (B).
6. Hook the other end of the cable onto the outside portion of the
liftgate hinge on the other side of
the vehicle.
7. Pull on the cable to make sure it is secure.