2008 GMC ACADIA ECU

Adding Coolant
If more coolant is needed, add the proper DEX-COOL®
coolant mixture at the coolant recovery tank, but be
careful not to spill it.
If the coolant recovery tank is completely empty, add
coolant to the radiator. SeeEngine Overheating
on page 5-25.
{CAUTION:
Turning the radiator pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. With the coolant recovery tank, you will
almost never have to add coolant at the
radiator. Never turn the radiator pressure
cap — even a little — when the engine and
radiator are hot.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
Occasionally check the coolant level in the radiator. For
information on how to add coolant to the radiator,
seeCooling System on page 5-27.
Radiator Pressure Cap
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.
SeeEngine Compartment Overview on page 5-14for
more information on location.
5-24

7. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fan.8. By this time, the coolant level inside the radiator ller
neck may be lower. If the level is lower, add more of
the proper DEX-COOL
®coolant mixture through the
ller neck until the level reaches the base of the ller
neck. Replace the pressure cap.
At any time during this procedure if coolant begins to
ow out of the ller neck, reinstall the pressure cap. Be
sure to secure it tightly.
5-32

Make certain that all wheel nuts are properly
tightened. See “Wheel Nut Torque” under
Capacities and Specifications on page 5-107.
{CAUTION:
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
you change a wheel, remove any rust or
dirt from places where the wheel attaches
to the vehicle. In an emergency, you can
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. SeeChanging a Flat Tire on page 5-72.
Make sure the spare tire is stored securely. Push,
pull, and then try to rotate or turn the tire. If it
moves, tighten the cable. SeeStoring a Flat or
Spare Tire and Tools on page 5-84.
When It Is Time for New Tires
Various factors, such as maintenance, temperatures,
driving speeds, vehicle loading, and road conditions
inuence when you need new tires.
One way to tell when it is
time for new tires is to
check the treadwear
indicators, which will
appear when your tires
have only 1/16 inch
(1.6 mm) or less of tread
remaining.
5-63

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, seeSecondary Latch System on
page 5-81.
If it is visible, rst 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 did lower to the ground, continue
with Step 5 under “Removing the Spare Tire” listed
previously.
5. If you still cannot lower the spare tire to the ground,
seeSecondary Latch System on page 5-81.Removing the Flat Tire and
Installing the Spare Tire
1. Do a safety check before proceeding. SeeChanging
a Flat Tire on page 5-72for 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 at 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 at tire repaired or
replaced.
If your vehicle has aluminum wheels, remove the
wheel nut caps using the wheel wrench.
5-76

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.
6. Make sure the tire is stored securely. 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
Notice:Storing the full-size at tire in the
underbody hoist system can expose it to heat from
the exhaust system. This can damage the tire
and underbody hoist system. Do not store the
full-size at tire in the underbody hoist system.
1. Remove the cable package from the 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 at tire in the rear storage area with the
valve stem pointing toward the rear of the vehicle.
5-85

4. Hook on end of the cable onto the outside portion
of the liftgate hinge opposite (B).
5. Pull the cable (A) through the center of the
wheel (D), then the door striker (E), and the plastic
spare tire heat shield (C), as shown.6. Hook the other end of the cable onto the outside
portion of the liftgate hinge (B).
7. Pull on the cable to make sure it is secure.
8. Make sure the metal tube is centered at the striker.
5-86

Put back all tools as they were stored in the jack
storage compartment and put the compartment cover
back on.
1. Attach the tool bag to the jack.
2. Make sure that the bottom of the jack is facing
toward you.
3. Turn the jack (C) on its side and place it down on
the holding bracket.
4. Reinstall the wing bolt (B) by turning it clockwise.
5. To replace the cover, line up the tabs on the bottom
of the cover with the slots in the cover opening.
Push the cover in place, insuring that the upper front
and rear tabs are in the opening and push the
cover closed. Make sure that the center latch is fully
engaged. This secures the cover in place.
Store the center cap or the plastic bolt-on wheel covers
until a full size tire is put back on the vehicle. When you
replace the compact spare with a full-size tire, reinstall
the bolt-on wheel covers or the center cap. Hand-tighten
them over the wheel nuts, using the lug wrench.Compact Spare Tire
Although the compact spare tire was fully inated when
the vehicle was new, it can lose air after a time.
Check the ination pressure regularly. It should be
60 psi (420 kPa).
After installing the compact spare on the vehicle, stop
as soon as possible and make sure the spare tire
is correctly inated. The compact spare is made to
perform well at speeds up to 65 mph (105 km/h)
for distances up to 3,000 miles (5 000 km), so you can
nish your trip and have the full-size tire repaired or
replaced at your convenience. Of course, it is best
to replace the spare with a full-size tire as soon as
possible. The spare tire will last longer and be in good
shape in case it is needed again.
Notice:When the compact spare is installed, do
not take your vehicle through an automatic car wash
with guide rails. The compact spare can get
caught on the rails. That can damage the tire and
wheel, and maybe other parts of your vehicle.
Do not use the compact spare on other vehicles.
And do not mix the compact spare tire or wheel with
other wheels or tires. They will not t. Keep the
spare tire and its wheel together.
5-88

At Least Once a Month
Tire Ination Check
Inspect your vehicle’s tires and make sure they are
inated to the correct pressures. Do not forget to check
the spare tire. SeeInflation - Tire Pressure on
page 5-55. Check to make sure the spare tire is stored
securely. SeeChanging a Flat Tire on page 5-72.
Tire Wear Inspection
Tire rotation may be required for high mileage highway
drivers prior to the Engine Oil Life System service
notication. Check the tires for wear and, if necessary,
rotate the tires. SeeTire Inspection and Rotation on
page 5-62.
At Least Once a Year
Starter Switch Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular
brake. SeeParking Brake on page 2-35.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. Try to start the engine in each gear. The vehicle
should start only in PARK (P) or NEUTRAL (N).
If the vehicle starts in any other position, contact
your dealer/retailer for service.
6-9