trailer GMC ACADIA 2008 Owner's Guide

But let us say your specic vehicle is equipped with
some of the latest options and you have a front
seat passenger and two rear seat passengers with
some luggage and gear in the vehicle as well. You may
add 300 lbs (136 kg) to the front axle weight and
400 lbs (181 kg) to the rear axle weight. Your vehicle
now weighs:
Weight is still below 7,200 lbs (3 266 kg) and you may
think that you should subtract 700 additional pounds
(318 kg) from your trailering capacity to stay within
GCWR limits. Your maximum trailer would only be
7,800 lbs (3 538 kg). 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 nowweighs 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 inated to the upper limit
for cold tires. You will nd these numbers on the
Certication/Tire label. SeeLoading Your Vehicle on
page 4-21. Then be sure you do not go over the GVW
limit for your vehicle, including the weight of the
trailer tongue.
4-36

Hitches
It is important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads are
a few reasons why you will 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 do not seal them,
deadly carbon monoxide (CO) from your exhaust
can get into your vehicle. SeeEngine Exhaust
on page 2-38. Dirt and water can, too.
Safety Chains
You should always attach chains between your vehicle
and your trailer. Cross the safety chains under the tongue
of the trailer so that the tongue will not drop to 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 you can turn with your rig. And, never allow
safety chains to drag on the ground.
Trailer Brakes
If you tow more than 1,000 lbs (450 kg), use trailer
brakes. Because your vehicle has Antilock brakes, do not
try to tap into your vehicle’s hydraulic brake system. If you
do, both brake systems will not work well, or at all.
Be sure to read and follow the instructions for the trailer
brakes so you will be able to install, adjust and
maintain them properly.
4-37

Driving with a Trailer
Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you will want to
get to know your rig. Acquaint yourself 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 a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check all trailer hitch parts and
attachments, safety chains, electrical connector, lamps,
tires and mirror adjustment. If the trailer has electric
brakes, start your vehicle and trailer moving and then
apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your 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 your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
Passing
You will need more passing distance up ahead when you
are towing a trailer. And, because you are a good deal
longer, you will need to go much farther beyond the
passed vehicle before you can return to your lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, just 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. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you’re turning with a trailer, make wider turns
than normal. Do this so your trailer won’t strike
soft shoulders, curbs, road signs, trees or other objects.
Avoid jerky or sudden maneuvers. Signal well in
advance.
4-38

Turn Signals When Towing a Trailer
When you tow a trailer, your vehicle may need a
different turn signal asher and/or extra wiring. Check
with your dealer/retailer. The arrows on your instrument
panel will ash whenever you signal a turn or lane
change. Properly hooked up, the trailer lamps will also
ash, telling other drivers you’re about to turn,
change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It
is important to check occasionally to be sure the trailer
bulbs are still working.
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 do not 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.
4-39

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 is
how to do it:
1. Apply your regular brakes, but do not 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.
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 are
pulling a trailer. SeeScheduled Maintenance on
page 6-4for more information. Things that are especially
important in trailer operation are automatic transmission
uid (do not overll), 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 are trailering, it is a good idea
to review this information before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
4-40

Trailer Wiring Harness
Your vehicle is equipped with the following wiring
harness for towing a trailer.
Basic Trailer Wiring
If your vehicle is equipped for heavy duty trailering, 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
Black: Ground
Light Green: Back-up Lamps
Red/Black: Battery Feed
Dark Blue: Trailer Brake**The fuse for this circuit is installed in the underhood
electrical center, but the wires are not connected. They
should be connected by your dealer/retailer or a
qualied service center.
If the back-up lamp circuit is not functional, contact your
dealer/retailer.
If you are charging a remote (non-vehicle) battery, press
the Tow/Haul mode switch located on the center
console near the climate controls. 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 5-25.
4-41

Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your vehicle can
affect the airow around it. This can cause wind
noise and can affect fuel economy and windshield
washer performance. Check with your dealer/retailer
before adding equipment to the outside of your vehicle.
Fuel
Use of the recommended fuel is an important part of the
proper maintenance of your vehicle. To help keep the
engine clean and maintain optimum vehicle
performance, we recommend the use of gasoline
advertised as TOP TIER Detergent Gasoline.
Gasoline Octane
Use regular unleaded gasoline with a posted octane
rating of 87 or higher. For best performance or
trailer towing, you could choose to use middle grade 89
octane unleaded gasoline. If the octane rating is less
than 87, you might notice an audible knocking noise
when you drive, commonly referred to as spark knock. If
this occurs, use a gasoline rated at 87 octane or
higher as soon as possible. If you are using gasoline
rated at 87 octane or higher and you hear heavy
knocking, the engine needs service.
Gasoline Specications
At a minimum, gasoline should meet ASTM specication
D 4814 in the United States or CAN/CGSB-3.5 or
3.511 in Canada. Some gasolines contain an
octane-enhancing additive called methylcyclopentadienyl
manganese tricarbonyl (MMT). We recommend
against the use of gasolines containing MMT. See
Additives on page 5-7for additional information.
5-6

If No Steam Is Coming From Your
Engine
If you get an engine overheat warning but see or hear
no steam, the problem may not be too serious.
Sometimes the engine can get a little too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. If your air conditioner is on, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the windows as necessary.
3. If you are in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving — DRIVE (D) or LOW (L).
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning does not come back on, you can drive
normally.
If the warning continues, pull over, stop, and park your
vehicle right away.If there is still no sign of steam, idle the engine for three
minutes while you are parked. If you still have the
warning, turn off the engine and get everyone out of the
vehicle until it cools down. Also, see “Overheated
Engine Protection Operating Mode” later in this section.
You may decide not to lift the hood but to get service
help right away.
Overheated Engine Protection
Operating Mode
This emergency operating mode lets your vehicle be
driven to a safe place in an emergency situation. If an
overheated engine condition exists, an overheat
protection mode which alternates ring groups of
cylinders helps prevent engine damage. In this mode,
there is a signicant loss in power and engine
performance. The temperature gage indicates an
overheat condition exists. Driving extended distances
and/or towing a trailer in the overheat protection
mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any
repair. The engine oil will be severely degraded.
Repair the cause of coolant loss, change the oil and
reset the oil life system. SeeEngine Oil on
page 5-15.
5-26

Fuses Usage
LT PRK Left Parking Lamp
RT PRK Right Parking Lamp
TRLR PRK
LAMPTrailer Parking Lamps
AIRBAG Airbag System
PCM IGN Powertrain Control Module Ignition
AFS Adaptive Forward Lighting System
TRANS Transmission
REAR
CAMERARear Camera
EMISSION 1 Antilock Brakes System 2
TRLR BRK Trailer Brake
AWD All-Wheel-Drive System
TRLR PWR Trailer Power
EVEN COILS Even Injector Coils
RR HVAC Rear Climate Control System
SPARE Spare
ODD COILS Odd Injector Coils
SPARE Spare
LT HI BEAM Left High-Beam Headlamp
SPARE SpareFuses Usage
LT TRLR
STOP/TRNTrailer Left Stoplamp and Turn
Signal
EMISSION 2 Emission 2
ECM Engine Control Module
RT HI BEAM Right High-Beam Headlamp
RVC SNSR Regulated Voltage Control Sensor
RT TRLR
STOP/TRNTrailer Right Stoplamp and Turn
Signal
ECM 1 Engine Control Module 1
SPARE Spare
WPR/WSW Windshield Wiper/Washer
SPARE Spare
PWR OUTLET Power Outlet
AUX POWER Auxiliary Power
RT LO BEAM Right Low-Beam Headlamp
RR APO Rear Accessory Power Outlet
LT LO BEAM Left Low-Beam Headlamp
TCM Transmission Control Module
TRLR BCK/UP Trailer Back-up Lamps
HTD MIR Heated Outside Rearview Mirror
ABS MTR Antilock Brake System Motor
5-105

Fuses Usage
FOG LAMP Fog Lamps
HORN Horn
A/C CLTCH Air Conditioning Clutch
FUEL PUMP Fuel Pump
SPARE Spare
J-Case Fuses Usage
FAN 2 Cooling Fan 2
PWR L/GATE Power Liftgate
FAN 1 Cooling Fan 1
HVAC BLWR Climate Control System Blower
STRTR Starter
BATT 2 Battery 2
HTD WASH Heated Windshield Washer System
BATT 1 Battery 1
BATT 3 Battery 3
ABS MTR Antilock Brake System Motor
RR DEFOG Rear Defogger
S/ROOF/
SUNSHADESunroof, Sunshade
Relays Usage
FAN 3 Cooling Fan 3
FAN 2 Cooling Fan 2
PRK LAMP Park Lamp
FAN 1 Cooling Fan 1
RT TRLR
STOP/TRNTrailer Right Stoplamp and Turn
Signal
LT TRLR
STOP/TRNTrailer Left Stoplamp and Turn
Signal
IGN Ignition Main
CRNK Switched Power
PWR/TRN Powertrain
HI BEAM High-Beam Headlamps
WPR Windshield Wiper
WPR HI Windshield Wiper High Speed
RR DEFOG Rear Window Defogger
HID/LO BEAMHigh Intensity Discharge (HID)
Low-Beam Headlamps
SPARE Spare
FOG LAMP Fog Lamps
HORN Horn
A/C CMPRSR
CLTCHAir Conditioning Compressor Clutch
FUEL PUMP Fuel Pump
TRLR BCK/UP Trailer Back-up Lamps
5-106