2009 GMC ACADIA ECU

Recreational Vehicle
Towing
Recreational vehicle towing means
towing the vehicle behind another
vehicle – such as behind a
motorhome. The two most common
types of recreational vehicle towing
are known as “dinghy towing” (towing
the vehicle with all four wheels on the
ground) and “dolly towing” (towing
the vehicle with two wheels on the
ground and two wheels up on a
device known as a “dolly”).
Here are some important things to
consider before recreational
vehicle towing:
What is the towing capacity of the
towing vehicle? Be sure to read
the tow vehicle manufacturer’s
recommendations.
What is the distance that will be
travelled? Some vehicles have
restrictions on how far and how
long they can tow.
Is the proper towing equipment
going to be used? See your
dealer/retailer or trailering
professional for additional advice
and equipment recommendations.
Is the vehicle ready to be towed?
Just as preparing the vehicle for a
long trip, make sure the vehicle is
prepared to be towed. SeeBefore
Leaving on a Long Trip on
page 4-12.
Dinghy Towing
If the vehicle is front-wheel-drive, it
can be dinghy towed from the front.These vehicles may also be towed
by putting the front wheels on a dolly.
See “Dolly Towing” later in this
section.
If the vehicle is all-wheel-drive, it can
be dinghy towed from the front.
These vehicles can also be towed by
placing them on a platform trailer
with all four wheels off of the ground.
These vehicles cannot be towed
using a dolly.
For vehicles being dinghy towed, the
vehicle should be run at the
beginning of each day and at each
RV fuel stop for about ve minutes.
This will ensure proper lubrication of
transmission components. Re-install
the fuse to start the vehicle.
To tow the vehicle from the front
with all four wheels on the ground:
1. Position the vehicle to tow
and then secure it to the towing
vehicle.
2. Shift the transmission to P (Park)
and turn the ignition to
LOCK/OFF.
Driving Your Vehicle 4-21

Dolly Towing
(Front-Wheel-Drive
Vehicles Only)
To tow a front-wheel-drive vehicle
from the front with two wheels
on the ground:
1. Put the front wheels on a dolly.
2. Move the shift lever to P (Park).
3. Set the parking brake.4. Clamp the steering wheel in a
straight-ahead position with a
clamping device designed
for towing.
5. Remove the key from the
ignition.
6. Secure the vehicle to the dolly.
7. Release the parking brake.
Towing the Vehicle From
the Rear
Notice:Towing the vehicle from
the rear could damage it. Also,
repairs would not be covered by
the warranty. Never have the
vehicle towed from the rear.
Do not tow the vehicle from the rear.
Driving Your Vehicle 4-23

Safety Chains
Always attach chains between the
vehicle and the trailer. Cross
the safety chains under the tongue
of the trailer to help prevent the
tongue from contacting the road
if it becomes separated from
the hitch. Instructions about safety
chains may be provided by the
hitch manufacturer or by the
trailer manufacturer. Follow the
manufacturer’s recommendation
for attaching safety chains and do
not attach them to the bumper.
Always leave just enough slack
so the rig can turn. Never allow
safety chains to drag on the ground.
Trailer Brakes
A loaded trailer that weighs more
than 1,000 lbs (450 kg) needs
to have its own brake system that is
adequate for the weight of the
trailer. Be sure to read and follow
the instructions for the trailer brakes
so they are installed, adjusted
and maintained properly.Because the vehicle has antilock
brakes, do not try to tap into
the vehicle’s hydraulic brake system.
If you do, both brake systems will
not work well, or at all.
Driving with a Trailer
Towing a trailer requires a certain
amount of experience. Get to know
the rig before setting out for the open
road. Get acquainted with the feel of
handling and braking with the added
weight of the trailer. And always keep
in mind that the vehicle you are
driving is now longer and not as
responsive as the vehicle is by itself.
Before starting, 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. This checks the electrical
connection at the same time.During the trip, check occasionally
to be sure that the load is secure,
and that the lamps and any
trailer brakes are still working.
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
much farther beyond the passed
vehicle before returning to the lane.
Driving Your Vehicle 4-29

3. Keep turning the pressure cap
slowly and remove it.
4. Fill the radiator to the base of the
ller neck with the proper
DEX-COOL coolant mixture.
5. When coolant begins to ow out
of the ller neck, reinstall the
pressure cap. Be sure to secure
it tightly.6. Fill the coolant recovery tank to
the 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 run
until the upper radiator hose
feels warm. Any time during this
procedure, watch out for the
engine cooling fan(s).
5-20 Service and Appearance Care

9. If the coolant level inside the
radiator ller neck is low, add
more of the proper DEX-COOL
coolant mixture through the
ller neck until the level is back
up to the base of the ller
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. SeeEngine Coolant
Temperature Gage on page 3-40.The vehicle may also display
an ENGINE OVERHEATED
IDLE ENGINE and ENGINE
OVERHEATED STOP ENGINE
message in the Driver Information
Center (DIC). SeeDIC Warnings
and Messages on page 3-56.
You may decide not to lift the hood
when this warning appears, but
instead get service help right away.
SeeRoadside Assistance Program
on page 7-6.
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 re
while driving with no coolant, the
vehicle can be badly damaged.
The costly repairs would not be
covered by the vehicle warranty.
SeeOverheated Engine Protection
Operating Mode on page 5-23for
information on driving to a safe
place in an emergency.
Service and Appearance Care 5-21

Reset the Tire Pressure Monitor
System. SeeTire Pressure
Monitor Operation on page 5-44.
Make certain that all wheel
nuts are properly tightened.
See “Wheel Nut Torque” under
Capacities and Specifications
on page 5-96.
{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
(Continued)
CAUTION (Continued)
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 5-69.
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
Storing a Flat or Spare Tire and
Tools on page 5-78.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 the tires have only 1/16 inch
(1.6 mm) or less of tread remaining.
5-48 Service and Appearance Care

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, seeSecondary
Latch System on page 5-76.Removing the Flat Tire
and Installing the
Spare Tire
1. Do a safety check before
proceeding. SeeChanging a
Flat Tire on page 5-69for 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 the vehicle has aluminum
wheels, remove the wheel nut
caps using the wheel wrench.3. Loosen the wheel nuts — but do
not remove them — using the
lug wrench. For wheels with
a wheel lock key, use the wheel
lock key between the lock nut
and lug wrench. The key is
supplied in the front passenger
door pocket.
Notice:If this vehicle has wheel
locks and an impact wrench is
used to remove the wheel nuts,
the lock nut or wheel lock key
could be damaged. Do not use
an impact wrench to remove the
wheel nuts if this vehicle has
wheel locks.
5-72 Service and Appearance Care

Storing a Flat or Spare
Tire and Tools
Storing the Spare Tire
{CAUTION
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.
{CAUTION
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.
5-78 Service and Appearance Care