trailer GMC SIERRA DENALI 2003 Owners Manual

Starting and Operating Your
Vehicle
New Vehicle Break-In
Notices Your vehicle doesn’t need an elaborate
“break-in.” But
it will perform better in the long run
if you follow these guidelines:
* Keep your speed at 55 mph (88 km/h) or less for
the first
500 miles (805 km).
Don’t drive at any one speed - fast or slow - for
the first
500 miles (805 km). Don’t make
full-throttle starts.
Avoid making hard stops for the first 200 miles
(322 km) or so. During this time your new brake
linings aren’t yet broken
in. Hard stops with new
linings can mean premature wear and earlier
replacement. Follow this breaking-in guideline
every time you get new brake linings.
Don’t tow a trailer during break-in. See “Towing a
Trailer” in the Index for more information.
Ignition Positions
With your key in the ignition switch you can turn it to
four different positions.
c
A
~~~ ~
Notice: If your key seems stuck in LOCK and you
can’t turn
it, be sure you are using the correct key; if
so, is it all the way in? Turn the key only with
your hand. Using a tool to force
it could break the
key or the ignition switch. If none of these works,
then your vehicle needs service.
2-1 5

It is dangerous to get out 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 have 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). See “Shifting
Into Park
(P)” in the Index. If you’re pulling a
trailer, see “Towing a Trailer”
in the Index.
REVERSE
(R): Use this gear to back up.
Notice: Shifting to REVERSE (R) while your vehicle
is moving forward could damage your transmission.
Shift to REVERSE (R) only after your vehicle is
stopped.
To rock your vehicle back and forth to get out of snow, ice
or sand without damaging your transmission, see
If You
Are Stuck: In Sand, Mud, Ice or Snow on page 4-42.
NEUTRAL (N): In this position, your engine doesn’t
connect with the wheels. To restart when you’re already
moving, use NEUTRAL (N) only. Also, use
NEUTRF’
lk’’ when your vehicle is beir- towed.
Shifting into a drive gear while your engine
is
“racing” (running at high speed) is dangerous.
Unless your foot
is firmly on the brake pedal,
your vehicle could move very rapidly. You could lose control and
hit people or objects. Don’t
shift into a drive gear while your engine
is
racing.
Notice: Damage to your transmission caused by
shifting out of PARK
(P) or NEUTRAL (N) with
the engine racing isn’t covered by your warranty.
DRIVE (D): This position is for normal driving. If
you need more power for passing, and you’re:
0 Going less than about 35 mph (55 km/h), push your
Going about 35 mph (55 km/h) or more, push the
accelerator
pedal about halfway down.
accelerator all the way down.
You’ll shift down to the next gear and have more power.
2-1 9

DRIVE (D) can be used when towing a trailer, carrying a
heavy load, driving on steep hills or for off-road
driving. You may want to shift the transmission to
THIRD
(3) or, if necessary, a lower gear selection if the
transmission shifts too often.
THIRD
(3): This position is also used for normal driving,
however it offers more power and lower fuel economy
than DRIVE (D).
SECOND
(2): This position gives you more power but
lower fuel economy. You can use SECOND
(2) on
hills. It can help control your speed as you go down
steep mountain roads, but then you would also want to
use your brakes occasionally.
If you manually select SECOND
(2), the transmission
will drive in second gear. You may use this feature
for reducing the speed of the rear wheels when you are
trying to start your vehicle from a stop on slippery
road surfaces. FIRST
(1): This position
gives you even more power
(but lower fuel economy) than SECOND
(2). You
can use it on very steep hills, or in deep snow or mud.
If the shift lever is put in FIRST (1) while the vehicle
is moving forward, the transmission won’t shift into first
gear until the vehicle is going slowly enough.
Notice: If your rear wheels won’t turn, don’t try to
drive. This might happen
if you were stuck in
very deep sand or mud or were up against a solid
object. You could damage your transmission.
Also, if you stop when going uphill, don’t hold your
vehicle there with only the accelerator pedal.
This could overheat and damage the transmission.
Use your brakes or shift into PARK (P) to hold
your vehicle in position on a hill.
On cold days, approximately
32°F (OOC) or colder, your
transmission is designed to shift differently until the
engine reaches normal operating temperature. This is
intended to improve heater performance.
2-20

Tow/HauI 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.
I
00
When tow/haul is activated
the tow/haul symbol will
illuminate
on the
instrument panel cluster.
See
Tow/Haul Mode under
Towing a Trailer on
page 4-51 for 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.
2-2 1

Parking Brake
To set the parking brake, hold the regular brake pedal
down with your right foot. Push down the parking
brake pedal with your left foot.
A chime will activate and the warning light will flash
when the parking brake is applied and the vehicle
is moving at least
3 mph (5 km/h) for at least three
seconds.
If the ignition is on when the parking brake is released,
the brake system warning light will go
off.
Notice: Driving with the parking brake on can
cause your rear brakes
to overheat. You may have
to replace them, and you could also damage
other parts
of your vehicle.
If you are towing a trailer and are parking on any hill,
see
Towing a Trailer on page 4-51.
To release the parking brake, hold the regular brake
pedal down. Pull the bottom edge
of the lever, located
above the parking brake pedal, with the parking
brake symbol, to release the parking brake.
2-22

Shifting Into Park (P)
It can be dangerous to get out of your vehicle
if the shift lever is not fully
in PARK (P) with
the parking brake firmly set. Your vehicle can
roll. If you have 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,
use the steps that follow.
With four-wheel
drive, if your transfer case
is in NEUTRAL,
your vehicle will be free to roll, even if your
shift lever is in PARK (P).
So, be sure the
transfer case is
in a drive gear - not in
NEUTRAL. If you’re pulling a trailer, see
“Towing a Trailer’’
in the Index.
1. Hold the brake pedal down with your right foot and
2. Move the shift lever into PARK (P) like this:
set
the parking brake.
/ 1
I.
Pull the shift lever toward you.
2-23

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

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