2008 GMC ACADIA trailer

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

Maintenance Footnotes
(a)Visually inspect brake lines and hoses for proper
hook-up, binding, leaks, cracks, chafing, etc. Inspect
disc brake pads for wear and rotors for surface
condition. Inspect other brake parts, including calipers,
parking brake, etc. Check parking brake adjustment.
(b)Visually inspect front and rear suspension and
steering system for damaged, loose, or missing parts or
signs of wear. Inspect power steering lines and hoses
for proper hook-up, binding, leaks, cracks, chafing, etc.
(c)Visually inspect hoses and have them replaced if they
are cracked, swollen, or deteriorated. Inspect all pipes,
fittings and clamps; replace with genuine parts as
needed. To help ensure proper operation, a pressure test
of the cooling system and pressure cap and cleaning the
outside of the radiator and air conditioning condenser is
recommended at least once a year.
(d)Inspect wiper blades for wear, cracking, or
contamination. Clean the windshield and wiper blades,
if contaminated. Replace wiper blades that are worn
or damaged. See Windshield Wiper Blade Replacement
on page 5-47andWindshield, Backglass, and Wiper
Blades on page 5-94 for more information.(e)Make sure the safety belt reminder light and safety
belt assemblies are working properly. Look for any
other loose or damaged safety belt system parts. If you
see anything that might keep a safety belt system
from doing its job, have it repaired. Have any torn or
frayed safety belts replaced. Also see Checking
the Restraint Systems on page 1-77.
(f)Lubricate all key lock cylinders, hood latch
assemblies, secondary latches, pivots, spring anchor
and release pawl, hood and door hinges, rear folding
seats, and liftgate hinges. More frequent lubrication may
be required when exposed to a corrosive environment.
Applying silicone grease on weatherstrips with a
clean cloth will make them last longer, seal better,
and not stick or squeak.
(g)A fluid loss in any vehicle system could indicate
a problem. Have the system inspected and repaired
and the fluid level checked. Add fluid if needed.
(h)Change automatic transmission fluid if the vehicle is
mainly driven under one or more of these conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police, or delivery
service.
6-7

Tires (cont.)
Changing a Flat Tire....................................5-72
Cleaning....................................................5-95
Compact Spare Tire.....................................5-88
Different Size..............................................5-66
If a Tire Goes Flat.......................................5-71
Ination - Tire Pressure................................5-55
Inspection and Rotation................................5-62
Installing the Spare Tire................................5-76
Pressure Monitor Operation...........................5-58
Pressure Monitor System..............................5-57
Removing the Flat Tire.................................5-76
Removing the Spare Tire and Tools...............5-73
Secondary Latch System..............................5-81
Storing a Flat or Spare Tire and Tools............5-84
Tire Sidewall Labeling..................................5-49
Tire Terminology and Denitions....................5-52
Uniform Tire Quality Grading.........................5-67
Wheel Alignment and Tire Balance.................5-68
Wheel Replacement.....................................5-68
When It Is Time for New Tires......................5-63
Tow/Haul Mode...............................................2-34
Tow/Haul Mode Light.......................................3-55
Towing
Recreational Vehicle.....................................4-26
Towing a Trailer..........................................4-30
Your Vehicle...............................................4-26Traction
StabiliTrak®System....................................... 4-6
Transmission
Fluid, Automatic...........................................5-21
Transmission Operation, Automatic....................2-30
Turn and Lane-Change Signals.......................... 3-8
Turn Signal/Multifunction Lever........................... 3-8
U
Ultrasonic Rear Parking Assist (URPA)...............2-45
Uniform Tire Quality Grading............................5-67
Universal Home Remote System.......................2-50
Operation...................................................2-51
Using this Manual............................................... iii
V
Vehicle
Control........................................................ 4-3
Damage Warnings........................................... iv
Loading......................................................4-21
Symbols......................................................... iv
Vehicle Customization, DIC..............................3-75
Vehicle Data Recording and Privacy..................7-15
13