check engine HUMMER H3 2008 Owners Manual

If you set off the alarm by accident, you can turn it off
by pressing unlock on the remote keyless entry
transmitter, starting the vehicle with the correct key, or
by having OnStar
®unlock the doors. The alarm will
not stop if you try to unlock a door any other way.
Testing the Alarm
To test the alarm:
1. From inside the vehicle, activate the system by
locking the doors with the remote keyless entry
transmitter.
2. Unlock the door with the manual door lock and
open the door. This should set off the pre-alarm.
Wait 10 seconds for the full alarm to activate.
3. To turn the alarm off, press the unlock button
on the remote keyless entry transmitter or start
the engine.
If the alarm does not sound when it should but the
lights ash, check to see if the horn works. The horn
fuse may be blown. To replace the fuse, seeFuses
and Circuit Breakers on page 5-102.
If the alarm does not sound or the front turn signal
lamps do not ash, see your dealer/retailer for service.
Passlock®(U. S. Only)
Your vehicle has 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 an incorrect key is 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 engine is started.
SeeSecurity Light on page 3-39.
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/retailer.
Your vehicle is not protected by Passlock
®at this time.
See your dealer/retailer for service.
In an emergency, call the Roadside Assistance Center.
SeeRoadside Assistance Program on page 7-6.
Do not leave the key or device that disarms or
deactivates the theft deterrent system in the vehicle.
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PASS-Key®III+
The PASS-Key®III+ system operates on a radio
frequency subject to Federal Communications
Commission (FCC) Rules and with Industry Canada.
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
1. This device may not cause harmful interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation.
This device complies with RSS-210 of Industry Canada.
Operation is subject to the following two conditions:
1. This device may not cause interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
Changes or modications to this system by other than
an authorized service facility could void authorization to
use this equipment.
PASS-Key
®III+ uses a radio frequency transponder in
the key that matches a decoder in your vehicle.
PASS-Key®III+ Operation
(Canada Only)
Your vehicle has a passive theft-deterrent system.
The system is automatically armed when the key
is removed from the ignition.
The system is automatically disarmed when the key is
turned to ON/RUN.
You do not have to manually arm or disarm the system.
The security light will come on if there is a problem
with arming or disarming the theft-deterrent system.
The key uses a transponder that matches an immobilizer
control unit in your vehicle. Only the correct key will
start the vehicle. If the key is ever damaged, you may
not be able to start your vehicle.
When trying to start the vehicle, if the engine does not
start and the security light comes on, there may be
a problem with your theft-deterrent system. Turn
the ignition off and try again.
If the engine still does not start, and the key appears
to be undamaged, try another ignition key. At this
time, you may also want to check the fuse.
SeeFuses and Circuit Breakers on page 5-102.
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Starting Procedure
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. Do not race the engine
immediately after starting it. Operate the engine and
transmission gently to allow the oil to warm up
and lubricate all moving parts.
Your vehicle has a Computer-Controlled Cranking
System. This feature assists in starting the
engine and protects components. If the ignition
key is turned to the START position, and then
released when the engine begins cranking, the
engine will continue cranking for a few seconds or
until the vehicle starts. If the engine does not
start and the key is held in START for many
seconds, cranking will be stopped after 15 seconds
to prevent cranking motor damage. To prevent
gear damage, this system also prevents cranking if
the engine is already running. Engine cranking
can be stopped by turning the ignition switch
to ACC/ACCESSORY or LOCK/OFF.
Notice:Cranking the engine for long periods of
time, by returning the key to the START position
immediately after cranking has ended, can overheat
and damage the cranking motor, and drain the
battery. Wait at least 15 seconds between each try,
to let the cranking motor cool down.2. If the engine does not start after 5-10 seconds,
especially in very cold weather (below 0°F or−18°C),
it could be ooded with too much gasoline. Try
pushing the accelerator pedal all the way to the oor
and holding it there as you hold the key in START for
up to a maximum of 15 seconds. Wait at least
15 seconds between each try, to allow the cranking
motor to cool down. When the engine starts, let go of
the key and accelerator. If the vehicle starts briey
but then stops again, do the same thing. This clears
the extra gasoline from the engine. Do not race the
engine immediately after starting it. Operate the
engine and transmission gently until the oil warms
up and lubricates all moving parts.
Notice:The 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/retailer. If you do not, your
engine might not perform properly. Any resulting
damage would not be covered by your vehicle’s
warranty.
2-21

Move the louvers up or down to change the direction of
the airow. Use the thumbwheel under the outlets to
change the direction of the airow from left to right.
Operation Tips

Enable recirculation mode for maximum air
conditioning performance.
Clear away any ice, snow or leaves from the air
inlets at the base of the windshield that may
block the ow of air into your vehicle.
Use of non-GM approved hood deectors may
adversely affect the performance of the system.
Keep the path under the front seats clear of objects
to help circulate the air inside of your vehicle more
effectively.
Warning Lights, Gages, and
Indicators
This part describes the warning lights and gages on
your vehicle. The pictures help to 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 the
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 the
details show on the next few pages, some warning lights
come on briey when you start the engine just to let you
know they are 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 is
a problem with your vehicle.
When one of the warning lights comes on and stays on as
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 vehicle’s warning lights and
gages. They can be a big help.
Your vehicle may also have a Driver Information Center
(DIC) that works along with the warning lights and gages.
SeeDriver Information Center (DIC) on page 3-40for
more information.
3-25

Speedometer and Odometer
The speedometer lets you see your speed in both miles
per hour (mph) and kilometers per hour (km/h).
The odometer shows how far your vehicle has been
driven, in either miles (used in the United States)
or kilometers (used in Canada).
The odometer mileage can be checked without the
vehicle running by pressing the trip information stem.
See “Odometer” underDIC Operation and Displays
on page 3-40for more information.
If the cluster is replaced the new one will automatically
detect and update the vehicle’s accumulated mileage.
Trip Odometer
Your vehicle has a trip odometer that can tell you how
far your vehicle has been driven since you last set
the trip odometer to zero.
See “Trip Odometer” underDIC Operation and Displays
on page 3-40for more information.
Tachometer
The 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.3.7L L5 Shown,
5.3L V8 Similar
3-27

Airbag Readiness Light
There is an airbag readiness light on the instrument
panel cluster, which shows the airbag symbol. The
system checks the airbag’s electrical system for
malfunctions. The light tells you if there is an electrical
problem. The system check includes the airbag
sensor, the pretensioners, the airbag modules, the
wiring and the crash sensing and diagnostic module.
For more information on the airbag system, seeAirbag
System on page 1-54.
This light will come on
when you start your
vehicle, and it will ash
for a few seconds.
The light should go out
and the system is ready.
If the airbag readiness light stays on after you start
the vehicle or comes on when you are driving,
your airbag system may not work properly. Have
your vehicle serviced right away.{CAUTION:
If the airbag readiness light stays on after you
start your vehicle, it means the airbag system
may not be working properly. The airbags in
your vehicle may not inate in a crash, or they
could even inate without a crash. To help
avoid injury to yourself or others, have your
vehicle serviced right away if the airbag
readiness light stays on after you start your
vehicle.
The airbag readiness light should ash for a few
seconds when you start the engine. If the light does not
come on then, have it xed immediately. If there is a
problem with the airbag system, an airbag Driver
Information Center (DIC) message may also come on.
SeeDIC Warnings and Messages on page 3-43for
more information.
3-29

Charging System Light
This 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. A charging system
Driver Information Center (DIC) message may also
appear. SeeDIC Warnings and Messages on page 3-43
for more information. This light could indicate that you
have problems with a generator drive belt, or another
electrical problem. Have it checked right away. 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.
Up-Shift Light
Your vehicle may have an
up-shift light.
When this light comes on, you should shift to the next
higher gear if weather, road, and traffic conditions allow
you to.
SeeManual Transmission Operation on page 2-26for
more information.
3-32

Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
If the gage pointer is in the shaded area of the gage,
the engine is too hot. It means that your engine coolant
has overheated. If you have been operating your
vehicle under normal driving conditions, you should pull
off the road, stop your vehicle and turn off the engine
as soon as possible.
SeeEngine Overheating on page 5-29for more
information.
Tire Pressure Light
This light comes on briey
when the engine is started.
This light will also come on when one or more of your
tires are signicantly underinated.
A tire pressure message in the Driver Information
Center (DIC), may accompany the light. SeeDIC
Warnings and Messages on page 3-43for more
information.
Stop and check your tires as soon as it is safe to do so.
If underinated, inate to the proper pressure. See
Tires on page 5-54for more information.
If a problem is detected with the Tire Pressure Monitor
System, this light will ash for approximately
60 seconds and then stay on solid for the remainder of
the ignition cycle. SeeTire Pressure Monitor System
on page 5-63for more information. United States
Canada
3-35

Malfunction Indicator Lamp
Check Engine Light
A computer system called OBD II (On-Board
Diagnostics-Second Generation) monitors operation of
the fuel, ignition, and emission control systems. It makes
sure 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 an OBD II
problem and service
is required.
Malfunctions often are indicated by the system before
any problem is apparent. This can 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, the emission controls might
not work as well, your vehicle’s fuel economy might
not be as good, and the engine might not run as
smoothly. This could lead to costly repairs that might
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 can cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This could
also result in a failure to pass a required Emission
Inspection/Maintenance test. SeeAccessories
and Modifications on page 5-3.
This light comes on, as a check to show it is working,
when the ignition is turned ON/RUN but the engine is not
running. If the light does not come on, have it repaired.
This light also comes on during a malfunction in
one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and could damage the emission control system on
your vehicle. Diagnosis and service might be
required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service might be required.
3-36

If the Light is Flashing
The following can prevent more serious damage to your
vehicle:
Reduce vehicle speed.
Avoid hard accelerations.
Avoid 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 the vehicle.
Turn the ignition 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/retailer
for service as soon as possible.
If the Light Is On Steady
You might 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 the Tank on page 5-8. The
diagnostic system can determine if the fuel cap hasbeen left off or improperly installed. A loose or missing
fuel cap allows 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 vehicle’s electrical system might be wet.
The condition is usually 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 causes
the engine not to run as efficiently as designed. You
might 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 might 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/retailer can check the vehicle. Your
dealer/retailer has the proper test equipment and
diagnostic tools to x any mechanical or electrical
problems that might have developed.
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