check engine light HUMMER H2 2004 Owners Manual

Passlock®
Your vehicle is equipped with the Passlock®
theft-deterrent system.
Passlock
®is a passive theft-deterrent system. Passlock®
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
®system is not working
properly and must be serviced by your dealer. Your
vehicle is not protected by Passlock
®at this time. You
may also want to check the fuse. SeeFuses and Circuit
Breakers on page 5-102. See your dealer for service.
In an emergency, call the Roadside Assistance Center.
SeeRoadside Assistance Program on page 7-5.
Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice:Your vehicle does not 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 rst 500 miles (805 km).
Do not drive at any one speed — fast or
slow — 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 4-75for more information.
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Off-Road Lamps
Notice:If you drive your vehicle through an
automatic car wash that does not have enough
clearance for any roof-mounted accessories (such
as off-road lamps or a roof basket) on your vehicle,
you can damage your vehicle. To avoid damaging
your vehicle in a car wash, remove any
roof-mounted accessories if you can, and do not
use an automatic car wash while roof-mounted
accessories are on your vehicle. SeeCleaning the
Outside of Your Vehicle on page 5-95for more
information.
The off-road lamps, if equipped, are designed to
enhance the appearance of your vehicle and to provide
auxiliary lighting when your vehicle is used off road.
The safety characteristics of these lamps are limited and
they are not intended to be used in conjunction with,
or in place of, existing vehicle lighting. The lamps are not
to be used on any public street or highway and are to
be covered when not in use. Check your state and local
laws before installing or using any auxiliary lighting.
In some states it may be necessary to remove the roof
lamps when operating the vehicle on the highway.
The button for the off-road lamps is located in the
overhead console.To use the lamps, be sure the engine is running.
Remove the covers form the lamps and press the button
to turn them on. Press the button again to turn them
off. An indicator light will glow near the button when the
lamps are on.
Notice:Turning on the off-road lamps before
removing the lamp covers could damage the
off-road lamps and the covers. Always remove the
covers before turning on the off-road lamps.
The off-road lamps will remain on even after the ignition
is turned off. The off-road lamps button must be
pressed to turn them off.
Interior Lamps
Instrument Panel Brightness
The thumbwheel for this feature is located next to the
exterior lamps control.
D(Instrument Panel Lights):Turn the thumbwheel
up or down to brighten or dim the instrument panel lights
and the radio display. This will only work if the
headlamps or parking lamps are on.
To turn on the dome lamps, with the vehicle doors
closed, turn the thumbwheel all the way up.
3-16

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 briey 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. SeeDIC Warnings
and Messages on page 3-56.
3-26

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 3-44.
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, seeAir Bag System on page 1-61.
3-28

Charging System Light
The charging system light
will come on briey 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. SeeDIC Warnings
and Messages on page 3-56.
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.
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.
3-32

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:Modications 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.
Modications 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.
3-38

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 Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and may damage the emission control system on
your vehicle. Diagnosis and service may be
required.
Light On Steady— 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 “If
the Light Is On Steady” 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 “If
the Light Is On Steady” following. If the light is still
ashing, follow the previous steps, and see your dealer
for service as soon as possible.
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. SeeFilling 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.
3-39

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, misring, 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,
your dealer can check the vehicle. Your dealer has
the proper test equipment and diagnostic tools to x any
mechanical or electrical problems that may have
developed.Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have or
may begin programs to inspect the emission control
equipment on your vehicle. Failure to pass this
inspection could prevent you from getting a vehicle
registration.
Here are some things you need to know to help your
vehicle pass an inspection:
Your vehicle will not pass this inspection if the check
engine light is on or not working properly.
Your vehicle will not pass this inspection if the OBD
(on-board diagnostic) system determines that critical
emission control systems have not been completely
diagnosed by the system. The vehicle would be
considered not ready for inspection. This can happen if
you have recently replaced your battery or if your
battery has run down. The diagnostic system is
designed to evaluate critical emission control systems
during normal driving. This may take several days
of routine driving. If you have done this and your vehicle
still does not pass the inspection for lack of OBD
system readiness, your GM dealer can prepare the
vehicle for inspection.
3-40

GM Oil Life System
Press the fuel information button until ENGINE OIL LIFE
appears in the display. The GM Oil Life System shows
an estimate of the oil’s remaining useful life. It will show
100% when the system is reset after an oil change. It
will alert you to change your oil on a schedule consistent
with your driving conditions.
Always reset the engine oil life after an oil change. To
reset the Oil Life System use the fuel button to reach the
ENGINE OIL LIFE screen and then press and hold the
select button for ve seconds while ENGINE OIL LIFE is
displayed. OIL LIFE RESET will appear on the display for
10 seconds to let you know the system is reset.
The DIC does not replace the need to maintain your
vehicle as recommended in the Maintenance Schedule
in this manual. Also, the oil change reminder will not
detect dusty conditions or engine malfunctions that may
affect the oil. Also, the oil change reminder does not
measure how much oil you have in your engine. So, be
sure to check your oil level often. SeeEngine Oil on
page 5-14.
Personalization Button
You can program certain features to a preferred setting
for up to two people. Press the personalization button
to scroll through the following personalization features.
All of the personalization options may not be available
on your vehicle. Only the options available will be
displayed on your DIC.
AUTOMATIC LOCKING
AUTOMATIC UNLOCKING
DELAYED LOCKING
REMOTE LOCK FEEDBACK
ALARM WARNING TYPE
REMOTE UNLOCK FEEDBACK
HEADLAMPS ON AT EXIT
PERIMETER LIGHTING
SEAT POSITION RECALL
EASY EXIT DRIVER SEAT
CURB VIEW ASSIST
DISPLAY LANGUAGE
DISPLAY UNITS (ENG/MET)
3-48

TIGHTEN FUEL CAP
If the vehicle’s fuel cap is not tightened properly this
message may appear along with the check engine light
on the instrument panel. SeeMalfunction Indicator
Lamp on page 3-38. Reinstall the fuel cap, making sure
to fully install the cap. SeeFilling 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 and message off.
CHECK WASHER FLUID
If the washer uid level is low, this message will appear
on the DIC. Adding washer uid will clear the message.
Pressing the select button will clear it from the DIC
display. This message will clear itself after 10 seconds
until the next ignition cycle.
TRACTION ACTIVE
When the traction control system has detected that any
of the vehicle’s wheels are slipping, the traction
control system will activate and this message will appear
on the DIC. SeeTraction Control System (TCS) on
page 4-9for more information.
TRANSMISSION HOT
If the transmission uid 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 uid temperature
returns to normal, the display will turn off and the
transmission shifting patterns will return to normal.
Notice:If you drive your vehicle while the
transmission uid is overheating and the
transmission temperature warning is displayed on
the instrument panel cluster and/or DIC, you
can damage the transmission. This could lead to
costly repairs that would not be covered by
your warranty. Do not drive your vehicle with
overheated transmission uid or while transmission
temperature warning is displayed.
3-59