engine GMC YUKON DENALI 2003 Owner's Manual

2. Set the driver’s and passenger’s temperature.
To find your comfort setting, start with a
74°F (23°C)
temperature setting and allow about
20 minutes
for the system to regulate. Turn the driver’s or
passenger’s side temperature knob
to adjust the
temperature setting as necessary.
If you choose the temperature setting of 60°F
(15°C) the system will remain at the maximum
cooling setting.
If you choose the temperature
setting of
90°F (32°C) the system will remain at the
maximum heat setting. Choosing either maximum
setting will not cause the vehicle to heat or cool
any faster.
Be careful not to cover the sensor located on the
top of the instrument panel near the windshield. This
sensor regulates air temperature based on sun
load, and also turns on your headlamps.
To avoid blowing cold air in cold weather, the
system will delay turning on the fan until warm air is
available. The length of delay depends on the
engine coolant temperature. Pressing the fan switch
will override this delay and change the fan to a
selected speed.
Manual Operation
You may manually adjust the air delivery mode or
fan speed.
0 (Off): Press this button to turn off the entire climate
control system. Outside air will still enter the vehicle, and
will be directed
to the floor. This direction can be changed
by pressing the mode button. The temperature can also
be adjusted using either temperature knob. Press the up
or down arrows on the fan switch, the defrost button, the
AUTO button, or the air conditioning button to turn the
system on when it is
off.
v (Fan): The switch with the fan symbol allows
you
to manually adjust the fan speed. Press the up
arrow
to increase fan speed and the down arrow
to decrease fan speed.
Pressing this button when the system
is off will turn the
system on.
% *d (Mode): Press this button to manually change the
direction of the airflow in your vehicle; keep pressing the
button until the desired mode appears on the display.
If you press the mode button to select an air delivery
mode, the display will change to show you the selected
air mode delivery. The display will then show the
current status of the system. When the system is turned
off, the display will go blank after displaying the
current status of the system.
3-21

Warning Lights, Gages and
Indicators
This part describes the warning lights and gages on
your vehicle. The pictures will help you locate them.
Warning lights and gages can signal that something is
wrong before it becomes serious enough
to cause
an expensive repair or replacement. Paying attention
to
your warning lights and gages could also save you
or others from injury.
Warning lights come on when there may be or is a
problem with one of your vehicle’s functions.
As you will
see in the details on the next few pages, some
warning lights come on briefly when you start the
engine
just to let you know they’re working. If you are
familiar with this section, you should not be alarmed
when this happens. Gages can indicate
when there may be or
is a problem
with one of your vehicle’s functions. Often gages
and warning lights work together
to let you know when
there’s a problem with your vehicle.
When one of the warning lights comes on and stays on
when you are driving, or when one of the gages
shows there may be a problem, check the section that
tells you what to do about it. Please follow this
manual’s advice. Waiting to do repairs can be
costly
- and even dangerous. So please get to know
your warning lights and gages. They’re
a big help.
Your vehicle also has a message center that works
along with warning lights and gages. See
DIC Warnings
and Messages on page
3-52.
3-28

Speedometer and Odometer
Your speedometer lets you see your speed in both
miles per hour (mph) and kilometers per hour (km/h).
Your vehicle’s odometer works together with the driver information center. You can set
a personal trip
and business trip odometer. See “Trip Information” under
DIC Operation and Displays on page 3-43.
The odometer mileage can be checked without the
vehicle running. Simply press the trip stem
on the
instrument panel cluster.
If your vehicle ever needs a new odometer installed, the
new one will be set
to the correct mileage total of the
old odometer.
Tachometer
Your tachometer displays the engine speed in
revolutions per minute (rpm).
Safety Belt Reminder Light
When the key is turned to RUN or START, a chime will
come
on for several seconds to remind people to
fasten their safety belts, unless the driver’s safety belt is
already buckled.
The safety belt light will
also come on and stay on
for several seconds,
then it will flash for
several more.
If the driver’s belt is already buckled, neither the chime
nor the light will come
on.
Notice: Do not operate the engine with the
tachometer in the shaded warning area, or engine
damage may occur.
3-30

If the word OFF or the off symbol is lit on the air bag
status indicator,
it means that the passenger sensing
system has turned
off the right front passenger’s frontal
air bag. See Passenger Sensing System on page
7 -8 7
for more on this, including important safety information.
If, after several seconds, all status indicator lights
remain on, or
if there are no lights at all, there may be a
problem with the lights or the passenger sensing
system. See your dealer for service.
__ -he ofl ..jdicator and the air bag readiness
light ever come on together, it means that
something may be wrong with the air bag
system.
If this ever happens, have the vehicle
serviced promptly, because an adult-size
person sitting in the right front passenger seat
may not have the protection of the frontal air
bag. See “Air Bag Readiness Light” in the
Index.
Charging System Light
The charging system light
will come on briefly when you turn on the ignition,
but the engine is
not
running, as a check to
show you it
is working.
It should go out once the engine is running. If it stays
on, or comes on while you are driving, you may have a
problem with the charging system.
It could indicate
that you have problems with a generator drive belt, or
another electrical problem. Have it checked right
away. Driving while this light is on could drain your
battery.
When this light comes on the DIC will also display the
battery not charging message. See
DIC Warnings
and Messages
on page 3-52.
If you must drive a short distance with the light on, be
certain to turn
off all your accessories, such as the radio
and air conditioner.
3-33

Voltmeter Gage
When your engine is not
running, but the ignition is
in
RUN, this gage
shows your battery’s state
of charge in
DC volts.
When the engine is running, the gage shows the
condition of the charging system. Readings between the
low and high warning zones indicate the normal
operating range.
Readings in the low warning zone may occur when a
large number of electrical accessories are operating in
the vehicle and the engine is left at an idle for an
extended period. This condition is normal since the
charging system is not able
to provide full power
at engine idle.
As engine speeds are increased, this
condition should correct itself as higher engine speeds allow the charging system
to create maximum power. 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.
3-34

w,
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 4-44.
Your brake system may not be working
properly
if the brake system warning light is
on. Driving with the brake system warning light
on can lead to an accident.
If the light is still
on after you’ve pulled off the road and stopped
carefully, have the vehicle towed for service.
Anti-Lock Brake System
Warning Light
With the anti-lock brake
system, this light will come
on when you start your
engine and may stay on for
several seconds.
That’s normal. If the light doesn’t come on then, have
it
fixed so it will be ready to warn you if there is a
problem.
3-35

If the light stays on, or comes on when you’re driving,
your vehicle needs service. You will also hear a
chime sound when the light is on steady.
If the regular
brake system warning light isn’t on, you still have
brakes, but you don’t have anti-lock brakes.
If the
regular brake system warning light is also on you don’t
have anti-lock brakes and there’s a problem with
your regular brakes. In addition to both lights, you will
also hear a chime sound on the first occurrence of
a problem and each time the car is shut off and then
restarted. See Brake System Warning Light on
page
3-34.
Traction Off Light
If you have the
Stabilitrak@system, this
light should come on briefly
when you turn the
ignition to
RUN.
If the light doesn’t come on then, the system may
require service; have it fixed
so it will be there to warn
you
if the system is turned off.
For more information on the traction off light, see
Stabilitrak@
System on page 4-9.
3-36
Engine Coolant Temperature Gage
~~ ~
United States
I I
Canada
This gage shows the engine coolant temperature.
It also provides an indicator
of how hard your vehicle is
working. During a majority of the operation, the gage
will read 21
0°F (100°C) or less. If you are pulling a load
or going up hills, it is normal for the temperature to
fluctuate and approach the 250°F (122°C) mark.
If the
gage reaches the 260°F
(125°C) mark, it indicates
that the cooling system
is working beyond its capacity.
See Engine Overheating on page
5-25.

Transmission Temperature Gage
--
United States Canada
Your vehicle is equipped with a transmission
temperature gage.
When your ignition is on, the gage shows the
temperature of the transmission fluid. The normal
operating range is from
100°F (38°C) to about 265°F
(1 30°C).
At approximately 265°F (130°C), the DIC will display a
TRANSMISSION HOT message and the transmission
will enter a transmission protection mode. When
the transmission enters the protection mode, you may
notice a change in the transmission shifting patterns.
The transmission will return to normal shifting patterns
when the transmission fluid temperature falls below
260°F
(1 27°C). See
Driver Information
Center (DIC) on page 3-43 for
further information.
If the transmission fluid reaches temperatures of
approximately 275°F (135°C) or greater, the DIC will
display a TRANS
HOT tDLE ENGtNE warning message
and a chime will sound. 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 (127°C).
If the transmission continues
to operate above 265°F
(1 30"C), please contact your
nearest dealer or the
GM Roadside Assistance Center.
Notice: 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,
* hot outside air temperatures,
0 hauling a large or heavy load,
low transmission fluid level,
high transmission fluid level,
0 restricted air flow to the radiator.

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.
Malfunction Indicator Lamp
Check Engine Light
Your vehicle is equipped
with
a computer which
monitors operation of the
fuel, ignition and emission
control systems.
This system is called OBD
II (On-Board
Diagnostics-Second Generation) and is intended to
assure that emissions are at acceptable levels for the
life of the vehicle, helping
to produce a cleaner
environment. The Check Engine light comes on
to
indicate that there is a problem and service is required.
Malfunctions often will be indicated by the system
before any problem is apparent. This may prevent more
serious damage
to your vehicle. This system is also
designed to
assist your service technician in correctly
diagnosing any malfunction.
Notice: If you keep driving your vehicle with this
light on, after a while, your emission controls
may not work as well, your fuel economy may not
be as good and your engine may not run as
smoothly. This could lead to costly repairs that may
not be covered by your warranty.
Notice: Modifications made to the engine,
transmission, exhaust, intake or fuel system of your
vehicle or the replacement of the original tires
with other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and may cause this light to come on.
Modifications to these systems could lead to costly
repairs not covered by your warranty. This may
also result
in a failure to pass a required Emission
Inspection/Maintenance test.
This light should come on, as a check to show you it is
working, when the ignition is on and the engine is
not running. If the light doesn’t come on, have it
repaired. This light will also come on during
a
malfunction in one of two ways:
Light Flashing - A misfire condition has been
detected.
A misfire increases vehicle emissions
and may damage the emission control system on
your vehicle. Dealer or qualified service center
diagnosis and service may be required.
3-38

Light On Steady - An emission control system
malfunction has been detected on your vehicle.
Dealer or qualified service center diagnosis
and service may be required.
If the Light is Flashing
The following may prevent more serious damage to
your vehicle:
Reducing vehicle speed.
Avoiding hard accelerations.
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 Filling
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.