2012 GMC ACADIA tow

Black plate (17,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-17
If the vehicle cannot be pulled
over, and must be shut off while
driving, turn the ignition to
ACC/ACCESSORY.
The steering can bind with the
wheels turned off center. If this
happens, move the steering wheel
from right to left while turning the
key to ACC/ACCESSORY. If this
does not work, then the vehicle
needs service.
ACC (ACC/ACCESSORY):This is
the position in which you can
operate the electrical accessories or
items plugged into the accessory
power outlets. This position unlocks
the ignition and steering wheel. Use
this position if the vehicle must be
pushed or towed.
R(ON/RUN): This position can be
used to operate the electrical
accessories and to display some
instrument panel warning and indicator lights. This position can
also be used for service and
diagnostics, and to verify the
proper operation of the malfunction
indicator lamp as may be required
for emission inspection purposes.
The switch stays in this position
when the engine is running.
The transmission is also unlocked
in this position. If you leave the
key in the ACC/ACCESSORY or
ON/RUN position with the engine
off, the battery could be drained.
You may not be able to start the
vehicle if the battery is allowed to
drain for an extended period of time.
/(START):
This is the position
that starts the engine. When the
engine starts, release the key.
The ignition switch will return to
ON/RUN for driving.
Key Lock Release
Vehicles with an automatic
transmission are equipped with an
electronic key lock release system.
This system is to prevent ignition
key removal unless the shift lever is
in P (Park).
The key lock release will not work
if the battery is charged less than
9‐volts, or uncharged. Try charging
or jump starting the battery. See
Jump Starting on page 10‑78.

Black plate (18,1)GMC Acadia/Acadia Denali Owner Manual - 2012
9-18 Driving and Operating
If charging or jump starting the
battery does not work, there is a
manual key lock release. Locate the
hole below the ignition lock. Insert a
tool or key into the opening. Locate
the lever, and press it toward the
driver while removing the key from
the ignition.
Starting the Engine
Move the shift lever to P (Park) or
N (Neutral). The engine will not start
in any other position. To restart the
engine when the vehicle is already
moving, use N (Neutral) only.
Notice:Do not try to shift to
P (Park) if the vehicle is moving.
If you do, you could damage the
transmission. Shift to P (Park)
only when the vehicle is stopped.
Starting Procedure
1. With your foot off the accelerator
pedal, turn the ignition to START.
When the engine starts, let go of
the key. The idle speed will slow
down as the engine warms. Do not race the engine
immediately after starting it.
Operate the engine and
transmission gently to allow
the oil to warm up and lubricate
all moving parts.
The vehicle has a
Computer-Controlled Cranking
System. This feature assists in
starting the engine and protects
components. If the ignition key is
turned to the START position,
and then released when the
engine begins cranking, the
engine will continue cranking
for a few seconds or until the
vehicle starts. If the engine
does not start and the key is
held in START, cranking will be
stopped after 15 seconds to
prevent cranking motor damage.
To prevent gear damage, this
system also prevents cranking if
the engine is already running.
Engine cranking can be stopped
by turning the ignition switch to
the ACC/ACCESSORY or
LOCK/OFF position.Notice:
Cranking the engine for
long periods of time, by returning
the key to the START position
immediately after cranking has
ended, can overheat and damage
the cranking motor, and drain the
battery. Wait at least 15 seconds
between each try, to let the
cranking motor cool down.
2. If the engine does not start
after five to 10 seconds,
especially in very cold weather
(below 0°F or −18°C), it could be
flooded with too much gasoline.
Try pushing the accelerator
pedal all the way to the floor
and holding it there as you hold
the key in START for up to a
maximum of 15 seconds.
Wait at least 15 seconds
between each try, to allow the
cranking motor to cool down.
When the engine starts, let go
of the key and accelerator.

Black plate (20,1)GMC Acadia/Acadia Denali Owner Manual - 2012
9-20 Driving and Operating
Retained Accessory
Power (RAP)
These vehicle accessories can be
used for up to 10 minutes after the
ignition key is turned off:
.Audio System
.Power Windows
.Sunroof (if equipped)
Power to the windows and sunroof
will work up to 10 minutes or until a
door is opened.
The radio continues to work for
10 minutes or until the driver door
is opened.
For an additional 10 minutes of
operation, close all the doors and
turn the key to ON/RUN and then
back to LOCK/OFF.
All these features will work when
the key is in the ON/RUN or
ACC/ACCESSORY positions.
Shifting Into Park
{WARNING
It can be dangerous to get out of
the vehicle if the shift lever is not
fully in P (Park) with the parking
brake firmly set. The vehicle can
roll. If you have left the engine
running, the vehicle can move
suddenly. You or others could be
injured. To be sure the vehicle will
not move, even when you are on
fairly level ground, use the steps
that follow. If you are pulling a
trailer, see Driving Characteristics
and Towing Tips on page 9‑45.
1. Hold the brake pedal down and set the parking brake.
See Parking Brake on page 9‑28
for more information.
2. Move the shift lever into P (Park) by holding in the button on the
shift lever and pushing the shift
lever all the way toward the front
of the vehicle. 3. Turn the ignition key to
LOCK/OFF.
4. Remove the key and take it with you. If you can leave the vehicle
with the ignition key in your
hand, the vehicle is in P (Park).
Leaving the Vehicle with the
Engine Running
{WARNING
It can be dangerous to leave the
vehicle with the engine running.
The vehicle could move suddenly
if the shift lever is not fully in
P (Park) with the parking brake
firmly set. And, if you leave the
vehicle with the engine running,
it could overheat and even catch
fire. You or others could be
injured. Do not leave the vehicle
with the engine running.

Black plate (23,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-23
Running the Vehicle
While Parked
It is better not to park with the
engine running. But if you ever have
to, here are some things to know.
{WARNING
Idling a vehicle in an enclosed
area with poor ventilation is
dangerous. Engine exhaust may
enter the vehicle. Engine exhaust
contains Carbon Monoxide (CO)
which cannot be seen or smelled.
It can cause unconsciousness
and even death. Never run the
engine in an enclosed area that
has no fresh air ventilation.
For more information, seeEngine
Exhaust on page 9‑22.
{WARNING
It can be dangerous to get out of
the vehicle if the automatic
transmission shift lever is not fully
in P (Park) with the parking brake
firmly set. The vehicle can roll.
Do not leave the vehicle when the
engine is running unless you
have to. If you have left the
engine running, the vehicle can
move suddenly. You or others
could be injured. To be sure the
vehicle will not move, even when
you are on fairly level ground,
always set the parking brake and
move the shift lever to P (Park).
Follow the proper steps to be
sure the vehicle will not move.
See Shifting Into Park on page 9‑20.
If parking on a hill and pulling a
trailer, see Driving Characteristics
and Towing Tips on page 9‑45.
Automatic
Transmission
The automatic transmission has a
shift lever located on the console
between the seats.
P (Park): This position locks the
front wheels. It is the best position
to use when starting the engine
because the vehicle cannot move
easily.

Black plate (24,1)GMC Acadia/Acadia Denali Owner Manual - 2012
9-24 Driving and Operating
{WARNING
It is dangerous to get out of the
vehicle if the shift lever is not fully
in P (Park) with the parking brake
firmly set. The vehicle can roll.
Do not leave the vehicle when the
engine is running unless you
have to. If you have left the
engine running, the vehicle can
move suddenly. You or others
could be injured. To be sure the
vehicle will not move, even when
you are on fairly level ground,
always set the parking brake and
move the shift lever to P (Park).
SeeShifting Into Park on
page 9‑20. If you are pulling a
trailer, see Driving Characteristics
and Towing Tips on page 9‑45. Make sure the shift lever is fully in
P (Park) before starting the engine.
The vehicle has an automatic
transmission shift lock control
system. You must fully apply the
regular brake first and then press
the shift lever button before shifting
from P (Park) when the ignition key
is in ON/RUN. If you cannot shift out
of P (Park), ease pressure on the
shift lever, then push the shift lever
all the way into P (Park) as you
maintain brake application. Then
press the shift lever button and
move the shift lever into another
gear. See
Shifting out of Park on
page 9‑21.
R (Reverse): Use this gear to
back up.
Notice: Shifting to R (Reverse)
while the vehicle is moving
forward could damage the
transmission. The repairs would
not be covered by the vehicle
warranty. Shift to R (Reverse)
only after the vehicle is stopped. To rock the vehicle back and forth to
get out of snow, ice, or sand without
damaging the transmission, see
If the Vehicle Is Stuck on page 9‑10.
N (Neutral):
In this position, the
engine does not connect with the
wheels. To restart the engine when
the vehicle is already moving, use
N (Neutral) only. Also, use
N (Neutral) when the vehicle is
being towed.
{WARNING
Shifting into a drive gear while the
engine is running at high speed is
dangerous. Unless your foot is
firmly on the brake pedal, the
vehicle could move very rapidly.
You could lose control and hit
people or objects. Do not shift
into a drive gear while the engine
is running at high speed.

Black plate (25,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-25
Notice:Shifting out of P (Park)
or N (Neutral) with the engine
running at high speed may
damage the transmission. The
repairs would not be covered by
the vehicle warranty. Be sure the
engine is not running at high
speed when shifting the vehicle.
D (Drive): This position is for
normal driving. It provides the best
fuel economy. If you need more
power for passing, and you are:
.Going less than 56 km/h
(35 mph), push the accelerator
pedal about halfway down.
.Going about 56 km/h (35 mph) or
more, push the accelerator all
the way down.
Notice: If the vehicle seems to
accelerate slowly or not shift
gears when you go faster, and
you continue to drive the vehicle
that way, you could damage the transmission. Have the vehicle
serviced right away. You can
drive in L (Low) when you are
driving less than 56 km/h (35 mph)
and D (Drive) for higher speeds
until then.
If the vehicle is stopped on a hill,
with your foot off the brake pedal,
the vehicle may roll. This is normal
and is due to the torque converter
designed to improve fuel economy
and performance. Use the brake to
hold the vehicle on a hill. Do not use
the accelerator pedal.
L (Low):
This position gives you
access to gear ranges. This
provides more engine braking but
lower fuel economy than D (Drive).
You can use it on very steep hills,
or in deep snow or mud.
Manual Mode
Electronic Range Select
(ERS) Mode
ERS mode allows you to choose
the top-gear limit of the transmission
and the vehicle's speed while
driving downhill or towing a trailer.
The vehicle has an electronic
shift position indicator within the
instrument panel cluster. When
using the ERS mode a number will
display next to the L, indicating the
current gear that has been selected.
To use this feature:
1. Move the shift lever to L (Low).
2. Press the plus/minus button located on the shift lever, to
increase or decrease the gear
range available.

Black plate (26,1)GMC Acadia/Acadia Denali Owner Manual - 2012
9-26 Driving and Operating
When you shift from D (Drive) to
L (Low), the transmission will shift to
a pre-determined lower gear range.
The highest gear available for this
pre-determined range is displayed
next to the L in the DIC. SeeDriver
Information Center (DIC) (Without
DIC Buttons) on page 5‑30 orDriver
Information Center (DIC) (With DIC
Buttons) on page 5‑25 for more
information. The number displayed
in the DIC is the highest gear that
the transmission will be allowed to
operate in. This means that all
gears below that number are
available. For example, when
4 (Fourth) is shown next to the L,
1 (First) through 4 (Fourth) gears
are automatically shifted by the
vehicle. The transmission will not
shift into 5 (Fifth) until the + (Plus)
button is used or you shift back
into D (Drive). While in L (Low), the transmission
will prevent shifting to a lower gear
range if the engine speed is too
high. You have a brief period of time
to slow the vehicle. If vehicle speed
is not reduced within the time
allowed, the lower gear range shift
will not be completed. You must
further slow the vehicle, then press
the
−(Minus) button to the desired
lower gear range.
Automatic Engine Grade Braking
is not available when the ERS is
active. It is available in D (Drive) for
both normal and Tow/Haul mode.
While using the ERS, cruise control
and the Tow/Haul mode can be
used. See Tow/Haul Mode following.Tow/Haul Mode
_
(Tow/Haul): The vehicle may
have a Tow/Haul mode.
The button is located on the
instrument panel under the climate
controls.
Push the button to activate the
system. Push it again to deactivate
the system. You can use this feature
to assist when towing or hauling a
heavy load.
When Tow/Haul is activated the
Tow/Haul symbol will come on
the instrument panel cluster.
See “Tow/Haul Mode” underDriving
Characteristics and Towing Tips on
page 9‑45 for more information.

Black plate (27,1)GMC Acadia/Acadia Denali Owner Manual - 2012
Driving and Operating 9-27
Automatic Engine Grade
Braking
Automatic Engine Grade Braking
assists when driving on a downhill
grade. It maintains vehicle speed by
automatically implementing a shift
schedule that uses the engine and
the transmission to slow the vehicle.
The system will automatically
command downshifts to reduce
vehicle speed, until the brake pedal
is no longer being pressed.
While in the Electronic Range
Select (ERS) mode, grade braking
is deactivated, allowing the driver
to select a range and limiting the
highest gear available. Grade
braking is available for normal
driving and in Tow/Haul mode.
SeeAutomatic Transmission on
page 9‑23.
Drive Systems
All-Wheel Drive
Vehicles with this feature always
send engine power to all four
wheels. It is fully automatic, and
adjusts itself as needed for road
conditions.
When using a compact spare tire
on an AWD vehicle, the system
automatically detects the compact
spare and disables AWD. To restore
AWD operation and prevent
excessive wear on the system,
replace the compact spare with a
full-size tire as soon as possible.
See Compact Spare Tire on
page 10‑77 for more information.
Brakes
Antilock Brake
System (ABS)
This vehicle has the Antilock Brake
System (ABS), an advanced
electronic braking system that helps
prevent a braking skid.
When the engine is started and the
vehicle begins to drive away, ABS
checks itself. A momentary motor or
clicking noise might be heard while
this test is going on, and it might
even be noticed that the brake
pedal moves a little. This is normal.
If there is a problem with ABS, this
warning light stays on. See Antilock
Brake System (ABS) Warning Light
on page 5‑22.