2003 GMC SIERRA DENALI towing

Running Your Engine While You
Are Parked
It’s better not to park with the engine running. But if you
ever have
to, here are some things to know.
Idling the engine with the climate control
system
off could allow dangerous exhaust into
your vehicle. See the earlier Caution under
“Engine Exhaust.’’
Also, idling in a closed-in place can let deadly
carbon monoxide (CO) into your vehicle even if
the fan is at the highest setting. One place
this
can happen is a garage. Exhaust - with
CO
- can come in easily. NEVER park in a
garage with the engine running.
Another closed-in place can be
a blizzard. See
“Winter Driving’’ in the Index.
It can be d,,,gersus to b-. dt of your vehicle
if the shift lever
is not fully in PARK (P) with
the parking brake firmly set. Your vehicle can
roll. Don’t leave your vehicle when the engine
is running unless you have to. If you’ve left the
engine running, the vehicle can move suddenly. You or others could be injured.
To
be sure your vehicle won’t move, even when
you’re on fairly level ground, always set your parking brake and move the shift lever to
PARK (P).
Follow the proper steps to be sure your vehicle won’t
move. See
Shifting Into Park (P) on page 2-23.
If you’re pulling a trailer, see Towing a Trailer on
page 4-5 1.
2-27

You can only drive for a short time with the reading in
either warning zone.
If you must drive, turn off all
unnecessary accessories.
Readings in either warning zone indicate a possible
problem in the electrical system. Have the vehicle
serviced as soon as possible.
Brake System Warning Light
With the ignition on, the brake system warning light will
flash when you set the parking brake. The light will
flash
if the parking brake doesn’t release fully. If you try
to drive with the parking brake engaged, a chime
will sound when the vehicle speed is greater than
3 mph (5 km/h).
Your vehicle’s hydraulic brake system is divided into two
parts.
If one part isn’t working, the other part can still
work and stop you. For good braking, though, you need
both parts working well.
If the warning light comes on and a chime sounds there
could be a brake problem. Have your brake system
inspected right away.
I BRAKE I
-
United States Canada
This light should come on briefly when you turn the
ignition key
to RUN. If it doesn’t come on then, have it
fixed
so it will be ready to warn you if there’s a problem.
If the light comes on while you are driving, pull off the
road and stop carefully. You may notice that the pedal is
harder
to push. Or, the pedal may go closer to the
floor. It may take longer
to stop. If the light is still on,
have the vehicle towed for service. See Towing
Your Vehicle on page 4-45.
3-34

See Driver Information Center (DIC) on page 3-43 for
further information.
If the transmission fluid reaches temperatures of
approximately 275°F
(1 35°C) or greater, the Driver
Information Center wiil display a
TRANS HOT IDLE
ENG warning message. Pull the vehicle off the roadway
when it
is safe to do so. Set the parking brake, place
the transmission in PARK
(P) and allow the engine
to idle until the transmission temperature falls below
260°F (1 27°C). If the transmission continues to operate
above
265°F (13O"C), contact your nearest dealer or
the
GM Roadside Assistance Center. See Roadside
Assistance Program
on page 7-5.
Notices If you keep driving your vehicle with the
transmission temperature gage above the normal
operating range, 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:
0 Towing a trailer
0 Hot outside air temperatures
0 Hauling a large or heavy load
0 Low transmission fluid level
High transmission fluid level
0 Restricted air flow to the radiator and the auxiliary
transmission oil cooler
(if equipped).
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, see
Scheduled Maintenance
on page
6-5 for the proper transmission maintenance
intervals.
3-37

If the Light is Flashing
The following may prevent more serious damage to
your vehicle:
Reducing vehicle speed.
Avoiding hard accelerations.
0 Avoiding steep uphill grades.
If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible.
If the light stops flashing and remains on steady, see “If
the Light
Is On Steady” following.
If the light continues to flash, when it is safe to do
so,
stop the vehicle. Find a safe place to park your vehicle.
Turn the key
off, wait at least 10 seconds and restart
the engine. If the light remains on steady, see
“If
the Light Is On Steady” following. If the light is still
flashing, follow the previous steps, and drive the vehicle
to your dealer or qualified service center for service.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If
so, reinstall the fuel cap, making sure to fully install
the cap. See
Fi//ing Your Tank on page 5-7. The
diagnostic system can determine
if the fuel cap has
been left
off or improperly installed. A loose or missing fuel
cap will allow fuel to evaporate into the atmosphere.
A few driving trips with the cap properly installed
should turn the light
off.
Did you just drive through a deep puddle of water?
If so, your electrical system may be wet. The condition
will usually be corrected when the electrical system
dries out. A few driving trips should turn the light
off.
Have you recently changed brands of fuel?
If
so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 5-5. Poor fuel quality will
cause your engine not to run
as efficiently as designed.
You may notice this as stalling after start-up, stalling
when you put the vehicle into gear, misfiring, hesitation
on acceleration or stumbling on acceleration. (These
conditions may go away once the engine is warmed up.)
This will be detected by the system and cause the
light to turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at least
one full tank of the proper fuel to turn the light off.
If none of the above steps have made the light turn off,
have your dealer or qualified service center check
the vehicle. Your dealer has the proper test equipment
and diagnostic tools to
fix any mechanical or electrical
problems that may have developed.
3-39

A reading in the low pressure zone may be caused by a
dangerously low oil level or some other problem
causing
low oil pressure. Check your oil as soon as
possible. See
DIC Warnings and Messages on
page 3-53
and ‘vgine Oil on page 5-13.
Don’t keep driving if the oil pressure is low. If
you do, your engine can become
so hot that it
catches fire. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice: Damage to your engine from neglected oil
problems can be costly and is not covered by
your warranty.
Cruise Control Light
The cruise light comes on
whenever you set your
cruise control. See “Cruise
Control” under
Turn
SignaVMultifunction Lever
on page 3-5.
Tow/HauI Mode Light
This light is displayed
when the tow/haul mode
has been activated.
For more information, see
Towing a Trailer on
page 4-5
I.
3-41

TRANSMISSION HOT
If the transmission fluid 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 transmission fluid temperature
returns to normal, the display will turn
off and the
transmission shifting patterns will return
to normal.
Nofice: 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
0 Hauling a large or heavy load
Low transmission fluid level
High transmission fluid level
transmission oil cooler.
0 Restricted air flow to the radiator and the auxiliary
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, see
Scheduled Maintenance
on page 6-5 for the proper transmission maintenance
intervals.
3-59

Section Driving Your Vehicle
Your Driving. the Road. and Your Vehicle .......... 4-2
Drunken Driving
............................................. 4-2
Control
of a Vehicle ........................................ 4-5
Defensive Driving
........................................... 4.2
Braking
......................................................... 4-6
Locking Rear Axle
.......................................... 4-8
Steering
........................................................ 4-9
Off -Road Recovery ....................................... 4-13
Passing
....................................................... 4-14
Loss
of Control ............................................. 4-15
Operating Your All-Wheel-Drive Vehicle
Off
Paved Roads ............................................ 4-16
Driving in Rain and on Wet Roads
................. -4-30
QUADRASTEERTM
....................................... 4-10
Driving at Night
................................ ..... 4-29
City Driving
.................................................. 4-33
Freeway Driving
........................................... 4-34 Before Leaving
on a Long
Trip ....................... 4-35
Hill and Mountain Roads
................................ 4-36
If You Are Stuck: In Sand, Mud,
Highway Hypnosis
........................................ 4.36
Winter Driving
.............................................. 4-38
Ice or Snow
.............................................. 4-42
Towing
.......................................................... 4-45
Towing Your Vehicle
..................................... 4-45
Recreational Vehicle Towing
........................... 4-45
Loading Your Vehicle
................................... -4-45
Truck-Camper Loading Information
.................. 4-48
Trailer Recommendations
.................. ...... 4-50
Pickup Conversion to
Chassis Cab
............................................. 4-50
Towing a Trailer
........................................... 4-51
4- 1

I
Higher Speeds (40 m.p.h./64 km/h and above)
J
At higher speeds the front and rear wheels will turn in
the same direction. This improves stability of the vehicle
during lane changes and sweeping turns.
(4 Wheel Steer tow mode): When towing a trailer
the
4 wheel steer tow mode provides enhanced
stability allowing the trailer to follow the path of the tow
vehicle more closely, especially during lane changes.
In this mode the system operates much like the
4 mode,
but is enhanced for trailer towing. It is recommended
for all types and weights
of trailers.
To engage the
4 wheel steer tow mode, press the 4
Wheel Steer button until the 4 and tow indicators light up
on the instrument panel.
If the tow indicator is flashing
you will have to center the steering wheel by turning it to
the left or right. While in the
4 wheel steer tow mode,
it is possible the steering wheel may be slightly
off
center. For more information, see Towing a Trailer on
page
4-5 I.
4-1 2