2008 GMC ACADIA wiring

Adding Equipment to Your
Airbag-Equipped Vehicle
Q:Is there anything I might add to or change
about the vehicle that could keep the airbags
from working properly?
A:Yes. If you add things that change your vehicle’s
frame, bumper system, height, front end or side
sheet metal, they may keep the airbag system from
working properly. Changing or moving any parts
of the front seats, safety belts, the airbag sensing
and diagnostic module, steering wheel, instrument
panel, roof-rail airbag modules, ceiling headliner
or pillar garnish trim, front sensors, side impact
sensors, rollover sensor module, or airbag wiring
can affect the operation of the airbag system.
In addition, your vehicle has a passenger sensing
system for the right front passenger’s position,
which includes sensors that are part of the
passenger’s seat. The passenger sensing system
may not operate properly if the original seattrim is replaced with non-GM covers, upholstery or
trim, or with GM covers, upholstery or trim
designed for a different vehicle. Any object, such as
an aftermarket seat heater or a comfort enhancing
pad or device, installed under or on top of the
seat fabric, could also interfere with the operation of
the passenger sensing system. This could either
prevent proper deployment of the passenger
airbag(s) or prevent the passenger sensing system
from properly turning off the passenger airbag(s).
SeePassenger Sensing System on page 1-70.
If you have any questions about this, you should
contact Customer Assistance before you modify
your vehicle. The phone numbers and addresses for
Customer Assistance are in Step Two of the
Customer Satisfaction Procedure in this manual.
SeeCustomer Satisfaction Procedure on page 7-2.
If your vehicle has rollover roof-rail airbags, see
Different Size Tires and Wheels on page 5-66
for additional important information.
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Q:Because I have a disability, I have to get my
vehicle modied. How can I nd out whether
this will affect my airbag system?
A:If you have questions, call Customer Assistance.
The phone numbers and addresses for Customer
Assistance are in Step Two of the Customer
Satisfaction Procedure in this manual. See
Customer Satisfaction Procedure on page 7-2.
In addition, your dealer/retailer and the service manual
have information about the location of the airbag sensors,
sensing and diagnostic module and airbag wiring.
Restraint System Check
Checking the Restraint Systems
Safety Belts
Now and then, make sure the safety belt reminder light
and all your belts, buckles, latch plates, retractors
and anchorages 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. Torn or
frayed safety belts may not protect you in a crash.
They can rip apart under impact forces. If a belt is torn
or frayed, get a new one right away.Make sure the safety belt reminder light is working. See
Safety Belt Reminders on page 3-41for more
information.
Keep safety belts clean and dry. SeeCare of Safety
Belts on page 5-92.
Airbags
The airbag system does not need regularly scheduled
maintenance or replacement. Make sure the airbag
readiness light is working. SeeAirbag Readiness Light
on page 3-42for more information.
Notice:If an airbag covering is damaged, opened,
or broken, the airbag may not work properly. Do
not open or break the airbag coverings. If there are
any opened or broken airbag covers, have the
airbag covering and/or airbag module replaced. For
the location of the airbag modules, seeWhat
Makes an Airbag Inflate? on page 1-68. See your
dealer/retailer for service.
1-77

Liftgate
{CAUTION:
It can be dangerous to drive with the liftgate
open because carbon monoxide (CO) gas can
come into your vehicle. You cannot see or
smell CO. It can cause unconsciousness and
even death.
If you must drive with the liftgate open, or if
electrical wiring or other cable connections
must pass through the seal between the body
and the liftgate:
Make sure all other windows are shut.
Turn the fan on your heating or cooling
system to its highest speed with the
recirculation mode off. That will force
outside air into your vehicle. See Climate
Control System in the index.
If you have air outlets on or under the
instrument panel, open them all the way.
If your vehicle has a power liftgate, disable
the power liftgate function.
SeePower Liftgate on page 2-14.If your vehicle has a power liftgate, seePower Liftgate
on page 2-14.
To unlock the liftgate, use the power door lock switch or
press the door unlock button on the Remote Keyless
Entry (RKE) transmitter twice. SeeRemote Keyless
Entry (RKE) System Operation on page 2-5.
To open the liftgate, press the touchpad on the
underside of the liftgate handle. The vehicle must be in
PARK (P) to open the liftgate. To close the liftgate,
use the pull cup or pull strap as an aid.
The liftgate has an electric latch. If the battery is
disconnected or has low voltage, the liftgate will not
open. The liftgate will resume operation when the battery
is reconnected and charged.
If the battery is properly connected and has adequate
voltage, and the liftgate still will not function, your vehicle
should be taken to a dealership for service.
2-13

Power Liftgate
Power Liftgate Operation
{CAUTION:
It can be dangerous to drive with the liftgate
open because carbon monoxide (CO) gas can
come into your vehicle. You cannot see or
smell CO. It can cause unconsciousness and
even death.
If you must drive with the liftgate open, or if
electrical wiring or other cable connections
must pass through the seal between the body
and the liftgate:
Make sure all other windows are shut.
Turn the fan on your heating or cooling
system to its highest speed with the
recirculation mode off. That will force
outside air into your vehicle. See Climate
Control System in the index.
CAUTION: (Continued)
CAUTION: (Continued)

If you have air outlets on or under the
instrument panel, open them all the way.
If your vehicle has a power liftgate, disable
the power liftgate function.
SeePower Liftgate on page 2-14.
Your vehicle may have a power liftgate. The vehicle
must be in PARK (P) to use the power feature.
The taillamps will ash and a chime will sound when the
power liftgate is used.
2-14

The indicator light does not come on when the ignition
is in LOCK/OFF or if no equipment is plugged into
the outlet.
If you try to connect equipment using more than
150 watts or a system fault is detected, a protection
circuit shuts off the power supply and the indicator
light turns off. To reset the circuit, unplug the item
and plug it back in or turn the Remote Accessory Power
(RAP) off and then back on. SeeRetained Accessory
Power (RAP) on page 2-27. The power restarts
when equipment using 150 watts or less is plugged
into the outlet and a system fault is not detected.
The power outlet is not designed for the following
electrical equipment and may not work properly if
these items are plugged into the power outlet:
Equipment with high initial peak wattage such
as: compressor-driven refrigerators and electric
power tools.
Other equipment requiring an extremely stable
power supply such as: microcomputer-controlled
electric blankets, touch sensor lamps, etc.
SeeHigh Voltage Devices and Wiring on page 5-99.
Climate Controls
Climate Control System
With this system you can control the heating, cooling,
defrost, defog, and ventilation of the vehicle.
Manual Operation
9
(Fan):Turn the left knob clockwise or
counterclockwise to increase or decrease the fan speed.
Turn the knob all the way counterclockwise to turn the
front system off.
Temperature Control:Turn the center knob clockwise
or counterclockwise to increase or decrease the
temperature of the air owing from the system.
3-26

Passenger Safety Belt Reminder Light
Several seconds after the engine is started, a chime
will sound for several seconds to remind the front
passenger to buckle their safety belt. This would only
occur if the passenger airbag is enabled. SeePassenger
Sensing System on page 1-70for more information.
The passenger safety belt light, located on the
instrument panel, will come on and stay on for
several seconds and then ash for several more.
This chime and light
are repeated if the
passenger remains
unbuckled and the
vehicle is in motion.
If the passenger’s safety belt is buckled, neither the
chime nor the light will come on.
Airbag Readiness Light
There is an airbag readiness light on the instrument
panel cluster, which shows the airbag symbol. The
system checks the airbag’s electrical system for
malfunctions. The light tells you if there is an electrical
problem. The system check includes the airbag
sensor, the pretensioners, the airbag modules, the
wiring and the crash sensing and diagnostic module.
For more information on the airbag system, see
Airbag System on page 1-61.
This light will come on
when you start your
vehicle, and it will ash
for a few seconds.
The light should go out
and the system is ready.
If the airbag readiness light stays on after you
start the vehicle or comes on when you are driving,
your airbag system may not work properly.
Have your vehicle serviced right away.
3-42

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

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