Page 84 of 600

Airbag Off Switch
If your instrument panel has one of the switches pictured
in the following illustrations your vehicle has an airbag off
switch that you can use to turn off the right front
passenger’s airbag.This switch should only be turned to the off position if the
person in the right front passenger’s position is a member
of a passenger risk group identi ed by the national
government as follows:
Infant.An infant (less than 1 year old) must
ride in the front seat because:
my vehicle has no rear seat;
my vehicle has a rear seat too small to accommodate
a rear-facing infant seat; or
the infant has a medical condition which, according
to the infant’s physician, makes it necessary for the
infant to ride in the front seat so that the driver can
constantly monitor the child’s condition.
Child age 1 to 12.A child age 1 to 12 must
ride in the front seat because:
my vehicle has no rear seat;
although children ages 1 to 12 ride in the rear
seat(s) whenever possible, children ages 1 to 12
sometimes must ride in the front because no space
is available in the rear seat(s) of my vehicle; or
the child has a medical condition which, according
to the child’s physician, makes it necessary for the
child to ride in the front seat so that the driver
can constantly monitor the child’s condition. United States
Canada
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Page 91 of 600

{CAUTION:
If the airbag readiness light in the instrument
panel cluster ever comes on and stays on, it
means that something may be wrong with the
airbag system. If this ever happens, have the
CAUTION: (Continued)
CAUTION: (Continued)
vehicle serviced promptly, because an
adult-size person sitting in the right front
passenger’s seat may not have the protection
of the frontal airbag. SeeAirbag Readiness
Light on page 3-35for more on this, including
important safety information.
Aftermarket equipment, such as seat covers, can affect
how well the passenger sensing system operates.
You may want to consider not using seat covers or other
aftermarket equipment if your vehicle has the passenger
sensing system. SeeAdding Equipment to Your
Airbag-Equipped Vehicle on page 1-86for more
information about modi cations that can affect how the
system operates.
{CAUTION:
Stowing of articles under the passenger’s seat
or between the passenger’s seat cushion and
seatback may interfere with the proper
operation of the passenger sensing system.
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Page 93 of 600

Q:What if I added a snow plow? Will it keep the
airbags from working properly?
A:We have designed our airbag systems to work
properly under a wide range of conditions,
including snow plowing with vehicles equipped with
the optional Snow Plow Prep Package (RPO
VYU). But do not change or defeat the snow plow’s
“tripping mechanism.” If you do, it can damage
your snow plow and your vehicle, and it may cause
an airbag in ation.
Q:Because I have a disability, I have to get my
vehicle modi ed. How can I nd out whether
this will affect my advanced airbag system?
A:Changing or moving any parts of the front seats,
safety belts, the airbag sensing and diagnostic
module (located under the driver’s seat), or
the inside rearview mirror can affect the operation
of the advanced airbag system. 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. SeeCustomer
Satisfaction Procedure on page 7-2.
Restraint System Check
Checking the Restraint Systems
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.
Also look for any opened or broken airbag covers, and
have them repaired or replaced. (The airbag system
does not need regular maintenance.)
Notice:If you damage the covering for the driver’s
or the right front passenger’s airbag, the airbag
may not work properly. You may have to replace the
airbag module in the steering wheel or both the
airbag module and the instrument panel for the right
front passenger’s airbag. Do not open or break
the airbag coverings.
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Page 113 of 600

Theft-Deterrent Systems
Vehicle theft is big business, especially in some cities.
Although your vehicle has a number of theft-deterrent
features, we know that nothing we put on it can make
it impossible to steal.
Content Theft-Deterrent
Your vehicle may be equipped with a content
theft-deterrent alarm system.
The security light is located
on the instrument panel
cluster. SeeSecurity Light
on page 3-49for additional
information.To activate the theft-deterrent system, do the following:
1. Close all the doors.
2. Lock the door with the remote keyless entry
transmitter. The security light should come on
and ash.
If the lock button on the remote keyless entry
transmitter is pressed, but a door is open, you may hear
three chimes indicating delayed locking is enabled. See
Delayed Locking on page 2-10for additional information.
Close the door and the content theft-deterrent system will
be activated.
If a locked door is opened without using the remote
keyless entry transmitter or OnStar, if equipped with
an active subscription, the alarm will go off. Your vehicle’s
lamps will ash and the horn will sound
for about two minutes, then will turn off to save the
battery power. If this occurs, you can turn off the alarm
by pressing unlock on the remote keyless entry
transmitter or by placing the key in the ignition and
turning it to START.
If your vehicle has a Driver Information Center (DIC),
you can customize your alarm warning. SeeDIC Vehicle
Customization on page 3-64for additional information.
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Page 114 of 600

The horn may chirp for 10 seconds before the alarm
goes off if the theft-deterrent system is activated using
the remote keyless entry transmitter and the driver’s door
is opened. If this occurs, you can turn off the alarm by
pressing unlock on the remote keyless entry transmitter
or by placing the key in the ignition and turning it to
START.
Here is how to avoid setting off the alarm by accident:
If you do not want to activate the theft-deterrent
system, the vehicle should be locked with the
door key after the doors are closed.
Always unlock a door with the remote keyless entry
transmitter.
If you set off the alarm by accident, turn off the alarm by
pressing unlock on the remote keyless entry transmitter
or by placing the key in the ignition and turning it to
START.
Testing the Alarm
The alarm can be tested by following these steps:
1. From inside the vehicle, activate the system by
locking the doors with the remote keyless entry
transmitter.
2. Wait for the security light to go out.
3. Unlock the door with the manual door lock and
open the door. This should set off the alarm.
4. Turn off the alarm by pressing unlock on the remote
keyless entry transmitter or by placing the key in
the ignition and turning it to START.
If the alarm does not sound when it should, but the
vehicle’s headlamps ash, check to see if the horn
works. The horn fuse may be blown. To replace the
fuse, seeInstrument Panel Fuse Block on page 5-124
andUnderhood Fuse Block on page 5-127.
If the alarm does not sound or the vehicle’s headlamps
do not ash, see your dealer for service.
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Page 120 of 600

Automatic Transmission Operation
If your vehicle is has an automatic transmission, it
features an electronic shift position indicator within the
instrument panel cluster. This display must be powered
anytime the shift lever is moved out of PARK (P).
SeeFuses and Circuit Breakers on page 5-123.
There are several different positions for your shift lever.
See “Range Selection Mode” later in this section.PARK (P):This position locks your rear wheels. It is the
best position to use when you start your engine because
your vehicle cannot move easily. If your vehicle has the
Allison Transmission®, with the Power Takeoff (PTO),
use PARK (P) when starting. The Allison Transmission®
has a park pawl that is designed to hold the weight of
commercial medium duty trucks. Therefore, the Allison
Transmission
®uses larger parts than other automatic
transmissions. These larger parts may sometimes make
a clunk noise when the selector lever is moved from
DRIVE (D) or REVERSE (R) to PARK (P). This is normal
and there is no damage occurring during these shifts.
When parked on a hill, especially when loaded, you may
notice an increase in the effort to shift out of Park. See
Torque Lock (Automatic Transmission) underShifting
Into Park (P) (Automatic Transmission) on page 2-53for
more information.
Automatic Transmission
Allison Transmission®
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Page 125 of 600

Cold Weather Operation
(Allison Transmission®)
On cold days, approximately 32°F (0°C) or colder, your
automatic transmission is designed to shift differently.
The transmission uses a warm-up mode shift schedule
until the engine reaches normal operating temperature.
While the transmission is in warm-up mode it is normal for
transmission upshifts to be delayed or held longer. This
feature improves heater performance by giving quicker
vehicle warm-ups.
When temperatures are below−13°F (−25°C), the
transmission will prevent certain operations to protect
against damage. When active the DIC will display
the message “Trans in Warm-up”.
SeeDIC Warnings and Messages on page 3-55for
more information.
Tow/Haul Mode
If your vehicle has an automatic transmission, it may
have a Tow/Haul mode. If your vehicle has an
Allison Transmission
®see “Tow/Haul Mode (Allison
Transmission®) following. Tow/Haul mode adjusts
the transmission shift pattern to reduce shift cycling,
providing increased performance, vehicle control, and
transmission cooling when towing or hauling heavy loads.
The selector button is located on the end of the shift
lever. Turn the Turn Tow/Haul on and off by pressing
the button. When the Tow/Haul is on, a light on the
instrument panel cluster will come on.
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Page 126 of 600

SeeTow/Haul Mode Light on page 3-50for more
information.
If your vehicle is equipped with the Performance
Package-Enhanced Towing, activating the manual
selectable ride will adjust the shock absorber
characteristics to enhance the ride and handling of the
vehicle for towing or hauling heavy loads.
Also see Tow Haul Mode underTowing a Trailer on
page 4-67for more information.
Tow/Haul Mode
(Allison Transmission®)
If your vehicle has an Allison Transmission®,itmay
have a Tow/Haul mode. Tow/Haul mode adjusts the
transmission shift pattern to reduce shift cycling,
providing increased performance, vehicle control, and
transmission cooling when towing or hauling heavy loads.
The selector button is located on the end of the shift
lever. Turn the Turn Tow/Haul on and off by pressing
the button. When the Tow/Haul is on, a light on the
instrument panel cluster will come on.
SeeTow/Haul Mode Light on page 3-50for more
information.
Also see “Tow Haul Mode” underTowing a Trailer on
page 4-67for more information.
2-32