
2 (Second):This position reduces vehicle speed even
more than 3 (Third) without using the brakes. You
can use 2 (Second) on hills. It can help control vehicle
speed as you go down steep mountain roads, but
then you would also want to use the brakes off and on.
You may use this feature for reducing torque to the
rear wheels when you are trying to start the vehicle from
a stop on slippery road surfaces.
1 (First):This position reduces vehicle speed even
more than 2 (Second) without using the brakes. You can
use it on very steep hills, or in deep snow or mud.
If the shift lever is put in 1 (First) while the vehicle is
moving forward, the transmission will not shift into first
gear until the vehicle is going slowly enough.
Notice:Spinning the tires or holding the vehicle
in one place on a hill using only the accelerator
pedal may damage the transmission. The repair will
not be covered by the vehicle warranty. If you
are stuck, do not spin the tires. When stopping on a
hill, use the brakes to hold the vehicle in place.Tow/Haul Mode
Tow/haul is designed to assist while the vehicle is
pulling a large or heavy load or trailer. Tow/haul is
most useful while pulling such a load in rolling terrain,
in stop-and-go traffic, or when you need improved
low-speed control, such as when parking. The purpose
of the tow/haul mode is to:
•Reduce the frequency and improve the predictability
of transmission shifts,
•provide the same solid shift feel when pulling a heavy
load as when the vehicle is unloaded,
•improve control of vehicle speed while requiring less
throttle pedal activity.
Press this button located
to the right of the steering
wheel on the instrument
panel to turn tow/haul
mode on and off.
2-25

This indicator light on the
instrument panel cluster
comes on when the
tow/haul mode is on.
Tow/Haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. SeeTow/Haul Mode
on page 2-25for more information.
Tow/Haul is designed to be most effective when the
vehicle and trailer combined weight is at least 75 percent
of the vehicle’s Gross Combined Weight Rating
(GCWR). See “Weight of the Trailer” later in the section.
Tow/Haul is most useful under the following driving
conditions:
•When pulling a heavy trailer or a large or heavy
load through rolling terrain.
•When pulling a heavy trailer or a large or heavy
load in stop and go traffic.
•When pulling a heavy trailer or a large or heavy
load in busy parking lots where improved low
speed control of the vehicle is desired.Operating the vehicle in Tow/Haul when lightly loaded
or with no trailer at all will not cause damage. However,
there is no benefit to the selection of Tow/Haul when
the vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission
driving characteristics and reduced fuel economy.
Tow/Haul is recommended only when pulling a heavy
trailer or a large or heavy load.
Trailer Brakes
A loaded trailer that weighs more than 1,500 lbs
(680 kg) needs to have its own brake system that is
adequate for the weight of the trailer. Be sure to read
and follow the instructions for the trailer brakes so
they are installed, adjusted and maintained properly.
4-36

Radiator Pressure Cap
The radiator pressure cap is located near the center of
the engine compartment. SeeEngine Compartment
Overview on page 5-14for more information on location.
Notice:If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.
Engine Overheating
If your vehicle has the DURAMAX Diesel engine, see
the DURAMAX Diesel manual for more information.
The vehicle has an indicator to warn of engine
overheating.
You will find an engine coolant temperature gage on
your vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 3-33for more information.You may decide not to lift the hood when this warning
appears, but instead get service help right away.
SeeRoadside Assistance Program on page 7-7.
If you do decide to lift the hood, make sure the vehicle
is parked on a level surface.
Then check to see if the engine cooling fans are
running. If the engine is overheating, both fans should
be running. If they are not, do not continue to run
the engine and have the vehicle serviced.
See if the engine cooling fan speed increases when idle
speed is doubled by pushing the accelerator pedal down.
If it does not, your vehicle needs service. Turn off the
engine.
Notice:Engine damage from running the engine
without coolant is not covered by the warranty.
Notice:If the engine catches re because of being
driven with no coolant, your vehicle can be badly
damaged. The costly repairs would not be covered
by the vehicle warranty.
5-31

Perchlorate Materials Requirements, California...... 5-4
Power
Door Locks.................................................. 2-6
Retained Accessory.....................................2-20
Seat ............................................................ 1-3
Steering Fluid.............................................5-34
Windows....................................................2-14
Privacy..........................................................7-18
Event Data Recorders..................................7-18
Navigation System.......................................7-19
OnStar.......................................................7-19
Radio Frequency Identification.......................7-19
Programmable Automatic Door Locks.................. 2-7
R
Radiator Pressure Cap....................................5-31
Radio Frequency Identification (RFID), Privacy......7-19
Radio(s)........................................................3-67
Radios
Reception...................................................3-84
Setting the Clock.........................................3-64
Theft-Deterrent............................................3-82
Reading Lamps..............................................3-16
Rear Air Conditioning and Heating System.........3-22
Rear Axle......................................................5-45
Locking........................................................ 4-8
Rear Door Security Locks.................................. 2-8Rear Doors....................................................2-12
Rear Heating System......................................3-21
Rear Seat Operation......................................... 1-6
Rearview Mirrors.............................................2-32
Reclining Seatbacks.......................................... 1-3
Recommended Fluids and Lubricants.................6-13
Recreational Vehicle Towing.............................4-25
Remote Keyless Entry (RKE) System.................. 2-3
Remote Keyless Entry (RKE) System, Operation..... 2-4
Removing the Flat Tire and Installing the
Spare Tire..................................................5-84
Removing the Spare Tire and Tools...................5-81
Replacement Bulbs.........................................5-52
Replacement Parts, Maintenance......................6-15
Reporting Safety Defects
Canadian Government..................................7-15
General Motors...........................................7-16
United States Government............................7-15
Restraint System Check
Checking the Restraint Systems....................1-78
Replacing Restraint System Parts After
a Crash..................................................1-79
Retained Accessory Power...............................2-20
Roadside
Assistance Program....................................... 7-7
Rocking Your Vehicle to Get it Out....................4-19
Routing, Engine Drive Belt...............................6-16
Running the Vehicle While Parked.....................2-31
9