Tow haul mode GMC SIERRA 2003 Owner's Manual

On cold days, approximately 32°F(0°C) or colder, your
transmission is designed to shift differently until the
engine reaches normal operating temperature. This is
intended to improve heater performance.
Tow/Haul Mode
Your vehicle may be equipped with a tow/haul mode.
The switch is located on the end of the column shift
lever. You can use this feature to assist when towing or
hauling a heavy load.When tow/haul is activated
the tow/haul symbol will
illuminate on the
instrument panel cluster.
SeeTow/Haul Modeunder
Towing a Trailer on
page 4-53for more
information.
All-Wheel Drive
With this feature, engine power is sent to all four wheels
all the time.
This is like four-wheel drive, but there is no separate
lever or switch to engage or disengage the front axle.
It is fully automatic, and adjusts itself as needed for road
conditions.
2-21
2003 - Sierra Denali

Instrument Panel Overview...............................3-2
Hazard Warning Flashers................................3-4
Other Warning Devices...................................3-4
Horn .............................................................3-5
Tilt Wheel.....................................................3-5
Turn Signal/Multifunction Lever.........................3-5
Exterior Lamps.............................................3-11
Interior Lamps..............................................3-15
Accessory Power Outlets...............................3-16
Ashtrays and Cigarette Lighter........................3-17
Climate Controls............................................3-18
Dual Automatic Climate Control System...........3-18
Warning Lights, Gages and Indicators.............3-24
Instrument Panel Cluster................................3-25
Speedometer and Odometer...........................3-26
Tachometer.................................................3-26
Safety Belt Reminder Light.............................3-27
Air Bag Readiness Light................................3-27
Air Bag Off Light..........................................3-28
Passenger Air Bag Status Indicator.................3-31
Battery Warning Light....................................3-33
Voltmeter Gage............................................3-33
Brake System Warning Light..........................3-34
Anti-Lock Brake System Warning Light.............3-35
Engine Coolant Temperature Gage..................3-36Transmission Temperature Gage.....................3-36
Malfunction Indicator Lamp.............................3-37
Oil Pressure Gage........................................3-40
Cruise Control Light......................................3-40
Tow/Haul Mode Light....................................3-41
Fuel Gage...................................................3-41
Low Fuel Warning Light.................................3-41
Driver Information Center (DIC).......................3-42
DIC Operation and Displays...........................3-42
DIC Warnings and Messages.........................3-51
Audio System(s).............................................3-56
Setting the Time...........................................3-57
Radio with Cassette and CD..........................3-57
Navigation/Radio System...............................3-70
Rear Seat Audio (RSA).................................3-71
CD Changer................................................3-73
Theft-Deterrent Feature..................................3-75
Audio Steering Wheel Controls.......................3-76
Understanding Radio Reception......................3-76
Care of Your Cassette Tape Player.................3-77
Care of Your CDs.........................................3-78
Care of Your CD Player................................3-78
Fixed Mast Antenna......................................3-78
XM™ Satellite Radio Antenna System
(United States Only)..................................3-78
Section 3 Instrument Panel
3-1
2003 - Sierra Denali

Tow/Haul Mode Light
This light is displayed
when the tow/haul mode
has been activated.
For more information, seeTowing a Trailer on
page 4-53.
Fuel Gage
When the ignition is on, the fuel gage tells you about
how much fuel you have left in your tank.
The gage willfirst indicate empty before you are out of
fuel, and you should get more fuel as soon as
possible.
Here are some situations you may experience with your
fuel gage. None of these indicate a problem with the
fuel gage.
•At the gas station, the fuel pump shuts off before
the gage reads full.
•It takes a little more or less fuel tofill up than the
fuel gage indicated. For example, the gage may
have indicated the tank was half full, but it actually
took a little more or less than half the tank’s
capacity tofill the tank.
•The gage goes back to empty when you turn off the
ignition.
Low Fuel Warning Light
The light next to the fuel gage will come on briefly when
you are starting the engine.
This light comes on when the fuel tank is low on fuel.
To turn it off, add fuel to the fuel tank. SeeFuel on
page 5-4.
United StatesCanada
3-41
2003 - Sierra Denali

SERVICE 4 WHEEL STEER
If a problem occurs with the 4 wheel steer system, this
message will appear on the DIC. If this message
appears, stop as soon as possible and turn off the
vehicle. Restart the vehicle and check for the message
on the DIC display. If the message is still displayed,
or appears again when you begin driving, the four wheel
steer system needs service.
TRACTION ACTIVE
When the traction control system had detected that any
of the vehicle’s wheels are slipping, the traction
control system will activate and this message will appear
on the DIC. For more information see“Traction Assist”
in the Index.
TRANSMISSION HOT
If the transmissionfluid temperature becomes high, the
message center will display this message.
When the transmission enters the protection mode, you
may notice a change in the transmission shifting
patterns. When the transmissionfluid temperature
returns to normal, the display will turn off and the
transmission shifting patterns will return to normal.Notice:If you keep driving your vehicle with the
transmission TRANS FLUID HOT message
displayed, you can damage the transmission. This
could lead to costly repairs that may not be covered
under your warranty.
The following situations can cause the transmission to
operate at higher temperatures:
•Towing a trailer
•Hot outside air temperatures
•Hauling a large or heavy load
•Low transmissionfluid level
•High transmissionfluid level
•Restricted airflow to the radiator and the auxiliary
transmission oil cooler.
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures
on a frequent basis, seeScheduled Maintenance
on page 6-5for the proper transmission maintenance
intervals.
3-55
2003 - Sierra Denali

You can tow in DRIVE (D). You may want to shift
the transmission to THIRD (3) or, if necessary, a
lower gear selection if the transmission shifts
too often (e.g., under heavy loads and/or hilly
conditions).
Three important considerations have to do with weight:
the weight of the trailer,
the weight of the trailer tongue
and the weight on your vehicle’s tires.
Tow/Haul Mode
Tow/haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. The purpose of the
tow/haul mode is to:
Reduce the frequency and improve the predictability
of transmission shifts when pulling a heavy trailer or
a large or heavy load.
Provide the same solid shift feel when pulling a
heavy trailer or a large or heavy load as when
the vehicle is unloaded.
Improve control of vehicle speed while requiring
less throttle pedal activity when pulling a heavy
trailer or a large or heavy load.
Your vehicle may be equipped with a switch at the end
of the shift lever which when pressed enables
tow/haul. When the switch is pressed, a light on theinstrument panel will illuminate to indicate that tow/haul
has been selected. Tow/haul may be turned off by
pressing the switch again, at which time the indicator
light on the instrument panel will turn off. The vehicle will
automatically turn off tow/haul every time it is started.
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 this 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 benet 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.
4-54
2003 - Sierra Denali

Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you’re turning with a trailer, make wider turns
than normal. Do this so your trailer won’t strike
soft shoulders, curbs, road signs, trees or other objects.
Avoid jerky or sudden maneuvers. Signal well in
advance.
Turn Signals When Towing a Trailer
The arrows on your instrument panel willash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will alsoash, telling other drivers
you’re about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel willash 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’s
important to check occasionally to be sure the trailer
bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don’t shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
You can tow in DRIVE (D). You may want to shift the
transmission to THIRD (3) or, if necessary, a lower gear
selection if the transmission shifts too often (e.g.,
under heavy loads and/or hilly conditions).
You may also want to activate the tow/haul mode if the
transmission shifts too often. See“Tow/Haul Mode”
earlier in this section.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) for a
few minutes before turning the engine off. If you do get
the overheat warning, seeEngine Overheating on
page 5-26.
4-59
2003 - Sierra Denali

Instrument Panel
Cluster.......................................................3-25
Overview..................................................... 3-2
Instrument Panel Brightness Control..................3-15
Instrument Panel Fuse Block............................5-92
Interior Lamps................................................3-15
J
Jump Starting.................................................5-40
K
Key Lock Cylinders Service..............................6-11
Keyless Entry System....................................... 2-3
Keys............................................................... 2-2
L
Lamps
Exterior......................................................3-11
Interior.......................................................3-15
Lamps On Reminder.......................................3-13
Lap Belt........................................................1-22
Lap-Shoulder Belt...........................................1-12
LATCH System
Child Restraints...........................................1-42LATCH System (cont.)
Securing a Child Restraint Designed for
the LATCH System...................................1-45
Leaving Your Vehicle With the Engine Running......2-24
Light
Air Bag Off .................................................3-28
Air Bag Readiness.......................................3-27
Anti-Lock Brake System Warning...................3-35
Battery Warning..........................................3-33
Brake System Warning.................................3-34
Cruise Control.............................................3-40
Low Fuel Warning.......................................3-41
Malfunction Indicator....................................3-37
Passenger Air Bag Status Indicator................3-31
Safety Belt Reminder...................................3-27
Tow/Haul Mode ...........................................3-41
Loading Your Vehicle.......................................4-47
Loading Your Vehicle for Off-Road Driving..........4-19
Locking Rear Axle...........................................4-10
Locks
Door ........................................................... 2-6
Power Door.................................................. 2-7
Programmable Automatic Door Locks............... 2-7
Loss of Control...............................................4-16
LOW COOLANT LEVEL..................................3-52
Low Fuel Warning Light...................................3-41
Lumbar
Power Controls............................................. 1-3
8
2003 - Sierra Denali

T
Tachometer....................................................3-26
Tailgate.........................................................2-10
Tailgate Removal............................................2-10
Taillamps.......................................................5-54
Temperature and Compass Display....................2-28
Testing the Alarm............................................2-14
Theft-Deterrent, Radio.....................................3-75
Theft-Deterrent Systems...................................2-13
Content Theft-Deterrent................................2-13
Passlock
®...................................................2-15
Tilt Wheel........................................................ 3-5
Tire Inflation Check.........................................6-10
Tires.............................................................5-56
Buying New Tires........................................5-60
Chains.......................................................5-64
Changing a Flat Tire....................................5-65
If a Tire Goes Flat.......................................5-64
Inflation -- Tire Pressure...............................5-57
Inspection and Rotation................................5-58
Spare Tire..................................................5-82
Uniform Tire Quality Grading.........................5-61
Wheel Alignment and Tire Balance
.................5-62
Wheel Replacement
.....................................5-62
When It Is Time for New Tires
......................5-59
To Use the Engine Coolant Heater
....................2-18
Tonneau Cover
...............................................2-39
Top Strap
......................................................1-39
Top Strap Anchor Location
...............................1-40Torque Lock...................................................2-25
Total Weight on Your Vehicle’s Tires..................4-56
Tow/Haul Mode ...............................................2-21
Tow/Haul Mode Light.......................................3-41
Towing
Recreational Vehicle.....................................4-47
Towing a Trailer..........................................4-53
Your Vehicle...............................................4-46
Traction
Manual Selectable Ride................................. 4-9
TRACTION ACTIVE........................................3-55
Trailer
Recommendations.......................................4-52
Trailer Brakes.................................................4-57
Trailer Wiring Harness.....................................4-61
Transfer Case................................................5-45
Transmission
Fluid, Automatic...........................................5-20
Temperature Gage.......................................3-36
TRANSMISSION HOT.....................................3-55
Transmission Operation, Automatic....................2-19
Transmission, Transaxle, Transfer Case Unit
Repair Manual............................................7-10
Transportation Options...................................... 7-7
Traveling to Remote Areas...............................4-20
Trip Information Button....................................3-43
Trip Odometer
................................................3-26
Truck-Camper Loading Information
....................4-50
Turn and Lane Change Signals
.......................... 3-6
TURN SIGNAL ON
.........................................3-54
14
2003 - Sierra Denali