2004 GMC YUKON XL DENALI check engine

3. Pull (push if you are exiting the third row with no
assistance) the seat forward until it stops.
{CAUTION:
If the seatback isn't locked, it could move
forward in a sudden stop or crash. That could
cause injury to the person sitting there. Always
press rearward on the seatback to be sure it is
locked.
{CAUTION:
A safety belt that is improperly routed, not
properly attached, or twisted won't provide the
protection needed in a crash. The person
wearing the belt could be seriously injured.
After raising the rear seatback, always check
to be sure that the safety belts are properly
routed and attached, and are not twisted.
Be sure to return the seat to the passenger position
when ®nished. Pull forward and push rearward on the
seat to make sure it is locked in place.
Heated Seats
The buttons used to
control this feature are
located on the back of the
center console. The
engine must be running for
the heated seat feature
to work.
To heat the seat, press the button to cycle through the
temperature settings of high and low. Press the
button a third time to turn the seats off. An Indicator
light will glow for each heat setting when the seats are
operating.
The heated rear seats will shut off automatically when
the ignition is turned off.
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Passlockž
Your vehicle is equipped with the Passlockž
theft-deterrent system.
Passlockžis a passive theft-deterrent system. Passlockž
enables fuel if the ignition lock cylinder is turned with
a valid key. If a correct key is not used or the ignition
lock cylinder is tampered with, the fuel system is
disabled and the vehicle will not start.
During normal operation, the security light will turn off
approximately ®ve seconds after the key is turned
to RUN.
If the engine stalls and the security light ¯ashes, wait
about 10 minutes until the light stops ¯ashing before
trying to restart the engine. Remember to release
the key from START as soon as the engine starts.
If the engine does not start after three tries, the vehicle
needs service.
If the engine is running and the security light comes on,
you will be able to restart the engine if you turn the
engine off. However, your Passlock
žsystem is
not working properly and must be serviced by your
dealer. Your vehicle is not protected by Passlock
žat this
time. You may also want to check the fuse. See
Fuses and Circuit Breakers on page 5-103. See your
dealer for service.
In an emergency, call the Roadside Assistance Center.
See
Roadside Assistance Program on page 7-5.
Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice:Your vehicle does not need an elaborate
ªbreak-in.º 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 ®rst 500 miles (805 km).
·Do not drive at any one speed Ð fast or
slow Ð for the ®rst 500 miles (805 km). Do not
make full-throttle starts.
·Avoid making hard stops for the ®rst 200 miles
(322 km) or so. During this time your new
brake linings are not 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.
·Do not tow a trailer during break-in. SeeTowing
a Trailer on page 4-51
for more information.
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Notice:Do not try to shift to PARK (P) if your
vehicle is moving. If you do, you could damage the
transmission. Shift to PARK (P) only when your
vehicle is stopped.
1. With your foot off the accelerator pedal, turn the
ignition key to START. When the engine starts,
let go of the key. The idle speed will go down as
your engine gets warm.
Notice:Holding your key in START for longer than
15 seconds at a time will cause your battery to
be drained much sooner. And the excessive heat
can damage your starter motor. Wait about 15
seconds between each try to help avoid draining
your battery or damaging your starter.
2. If it doesn't start within 10 seconds, push the
accelerator pedal all the way to the ¯oor, while you
hold the ignition key in START. When the engine
starts, let go of the key and let up on the accelerator
pedal. Wait about 15 seconds between each try.
When starting your engine in very cold weather
(below 0ÉF or-18ÉC), do this:
1. With your foot off the accelerator pedal, turn the
ignition key to START and hold it there up to
15 seconds. When the engine starts, let go of
the key.2. If your engine still won't start (or starts but then
stops), it could be ¯ooded with too much gasoline.
Try pushing your accelerator pedal all the way to the
¯oor and holding it there as you hold the key in
START for about three seconds. When the engine
starts, let go of the key and accelerator. If the
vehicle starts brie¯y but then stops again, do the
same thing, but this time keep the pedal down
for ®ve or six seconds. This clears the extra
gasoline from the engine.
Notice:Your engine is designed to work with the
electronics in your vehicle. If you add electrical
parts or accessories, you could change the way the
engine operates. Before adding electrical equipment,
check with your dealer. If you do not, your engine
might not perform properly.
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Warning Lights, Gages and
Indicators
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 brie¯y 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 3-57.
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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 ªTrip Informationº under
DIC Operation and Displays on page 3-46.
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).
Notice:If you operate the engine with the
tachometer in the shaded warning area, your vehicle
could be damaged, and the damages would not
be covered by your warranty. Do not operate
the engine with the tachometer in the shaded
warning area.
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 ¯ash for several more.
If the driver's belt is already buckled, neither the chime
nor the light will come on.
Air Bag Readiness Light
There is an air bag readiness light on the instrument
panel, which shows the air bag symbol. The system
checks the air bag's electrical system for malfunctions.
The light tells you if there is an electrical problem.
The system check includes the air bag sensors, the air
bag modules, the wiring and the crash sensing and
diagnostic module. For more information on the air bag
system, see
Air Bag Systems on page 1-72.
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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 1-81for 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.
{CAUTION:
If the off indicator 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 ªAir Bag Readiness Lightº in the
Index.
Charging System Light
The charging system light
will come on brie¯y 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 3-57.
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.
3-35

·Low transmission ¯uid level
·High transmission ¯uid level
·Restricted air ¯ow 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 6-4for the proper transmission maintenance
intervals.
Tire Pressure Light
If your vehicle is equipped
with the Tire Pressure
Monitor system, this light
will come on if the
system detects low tire
pressure.
A CHECK TIRE PRESSURE DIC message will
accompany the light.
This light will also come on for a bulb check when the
vehicle is started.See
Tire Pressure Monitor System on page 5-64for
more information.
For more information on the proper tire pressure, see
Loading Your Vehicle on page 4-44. For more
information on your tires, seeTires on page 5-54.
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
3-40

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:Modi®cations 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.
Modi®cations 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 does not come on, have it
repaired. This light will also come on during a
malfunction in one of two ways:
·Light FlashingÐ A mis®re condition has been
detected. A mis®re increases vehicle emissions and
may damage the emission control system on your
vehicle. Diagnosis and service may be required.
·Light On SteadyÐ An emission control system
malfunction has been detected on your vehicle.
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 ¯ashing and remains on steady, see ªIf
the Light Is On Steadyº following.
If the light continues to ¯ash, 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 ªIf
the Light Is On Steadyº following. If the light is still
¯ashing, follow the previous steps, and see your dealer
for service as soon as possible.
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