engine GMC ACADIA 2007 Manual PDF
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You may go further and think you must limit
tongue weight to less than 1,000 lbs (454 kg) to
avoid exceeding GVWR. But, you must still
consider the effect on the rear axle. Because your
rear axle now weighs 3,100 lbs (1 406 kg), you
can only put 900 lbs (408 kg) 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 you
with being able to handle only 600 lbs (272 kg) of
tongue weight. Since tongue weight is usually
at least 10 percent of total loaded trailer weight,
you can expect that the largest trailer your vehicle
can properly handle is 6,000 lbs (2 721 kg).
It is important that you make sure your vehicle
does not exceed any of its ratings — GCWR,
GVWR, RGAWR, Maximum Trailer Rating
or Tongue Weight. The only way to be sure you
are not exceeding any of these ratings is to weigh
your vehicle and trailer.Total Weight on Your Vehicle’s Tires
Be sure your vehicle’s tires are in ated to the upper
limit for cold tires. You’ll nd these numbers on the
Certi cation/Tire label. SeeLoading Your Vehicle
on page 361. Then be sure you don’t go over the
GVW limit for your vehicle, including the weight of
the trailer tongue.
Hitches
It’s important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough
roads are a few reasons why you’ll need the
right hitch. Here are some rules to follow:
The rear bumper on your 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 you have to make any holes in the body of
your vehicle when you install a trailer hitch?
If you do, then be sure to seal the holes later
when you remove the hitch. If you don’t seal
them, deadly carbon monoxide (CO) from your
exhaust can get into your vehicle. SeeEngine
Exhaust on page 138. Dirt and water can, too.
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Driving on Grades
Your vehicle is designed primarily as a passenger
and load carrying vehicle. If you tow a trailer,
your vehicle will require more frequent
maintenance due to the additional load. Because
of the added load of the trailer, your 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.
Reduce speed and shift to a lower gear before
you start down a long or steep downgrade. If you
don’t shift down, you might have to use your
brakes so much that they would get hot and no
longer work well.
On a long uphill grade, shift down and reduce
your speed to around 55 mph (88 km/h) to reduce
the possibility of the engine and the transmission
overheating.
Parking on Hills
{CAUTION:
You really should not park your vehicle,
with a trailer attached, on a hill.
If something goes wrong, your rig could
start to move. People can be injured, and
both your vehicle and the trailer can be
damaged.
But if you ever have to park your rig on a hill,
here’s how to do it:
1. Apply your regular brakes, but don’t shift
into PARK (P).
When parking uphill, turn your wheels away
from the curb. When parking downhill,
turn your wheels into the curb.
2. Have someone place chocks behind the
trailer wheels.
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3. When the chocks are in place, release the
regular brakes until the chocks absorb
the load.
4. Reapply the regular brakes. Then apply your
parking brake and shift into PARK (P).
5. Release the regular brakes.
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal
down while you:
start your 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
Your vehicle will need service more often
when you’re pulling a trailer. SeeScheduled
Maintenance on page 502for more information.
Things that are especially important in trailer
operation are automatic transmission uid
(don’t over ll), engine oil, axle lubricant, drive
belt, cooling system and brake system. Each of
these is covered in this manual, and the Index will
help you nd them quickly. If you’re trailering,
it’s a good idea to review this information before
you start your trip.
Check periodically to see that all hitch nuts and
bolts are tight.
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Trailer Wiring Harness
Your vehicle is equipped with the following wiring
harness for towing a trailer.
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
White: Ground
Light Green: Back-up Lamps
Red: Battery Feed*
Dark Blue: Trailer Brake*
*The fuses for these two circuits are installed in
the underhood electrical center, but the wires
are not connected. They should be connected by
your dealer/retailer or a quali ed service center.
If you are charging a remote (non-vehicle) battery,
press the tow/haul mode button located at the
end of the shift lever. This will boost the vehicle
system voltage and properly charge the battery.
If the trailer is too light for tow/haul mode, you can
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
Your cooling system may temporarily overheat
during severe operating conditions. SeeEngine
Overheating on page 410.
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