ignition HUMMER H2 2008 Service Manual

Automatic Headlamp System
When it is dark enough outside and the headlamp
switch is in AUTO, the automatic headlamp system will
turn on the headlamps at the normal brightness along
with other lamps such as the taillamps, sidemarker,
parking lamps, roof marker lamps, and the instrument
panel lights. The radio lights will also be dim.
To turn off the automatic headlamp system, turn the
exterior lamps switch to the off position and then
release. For vehicles rst sold in Canada, the
transmission must be in the PARK (P) position, before
the automatic headlamp system can be turned off.
The vehicle has a light sensor located on the top of
the instrument panel. Be sure it is not covered,
or the system will be on whenever the ignition is on.
The system may also turn on the headlamps when
driving through a parking garage, heavy overcast
weather, or a tunnel. This is normal.
There is a delay in the transition between the
daytime and nighttime operation of the Daytime
Running Lamps (DRL) and the automatic headlamp
systems so that driving under bridges or bright
overhead street lights does not affect the system.The DRL and automatic headlamp system will only be
affected when the light sensor sees a change in lighting
lasting longer than the delay.
If the vehicle is started in a dark garage, the automatic
headlamp system will come on immediately. Once
the vehicle leaves the garage, it takes approximately
one minute for the automatic headlamp system to
change to DRL if it is light outside. During that delay,
the instrument panel cluster may not be as bright
as usual. Make sure the instrument panel brightness
control is in the full bright position. SeeInstrument
Panel Brightness on page 3-18.
Instrument Panel Brightness
D(Instrument Panel Brightness):This feature
controls the brightness of the instrument panel lights
and is located next to the exterior lamp control.
Push the knob to extend out and then it can be turned.
Turn the knob clockwise or counterclockwise to
brighten or dim the instrument panel lights. Turning
the knob to the farthest clockwise position turns
on the dome lamps.
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Dome Lamps
The dome lamps come on when any door is opened
and turns off when all doors are closed.
The dome lamps can also be turned on by turning the
instrument panel brightness knob, located next to
the exterior lamps control, clockwise to the farthest
position. In this position, the dome lamps will remain
on whether a door is opened or closed.
Dome Lamp Override
The dome lamp override button is located next to the
exterior lamps control.
k(Dome Off):Press the button in and the dome
lamps remain off when a door is opened. Press
the button again to return it to the extended position so
that the dome lamps come on when a door is opened.
Entry/Exit Lighting
Your vehicle has an illuminated entry/exit feature.
When a door is opened or the key is removed from
the ignition, the dome lamps will come on if the
dome override button is in the out position.
Reading Lamps
There are reading lamps located in the overhead
console and on the DVD Rear Seat Entertainment (RSE)
system console, if equipped. Press the button located
next to each lamp to turn it on or off.
These lamps will also come on with the dome lamps.
Battery Run-Down Protection
This feature shuts off the dome lamps if they are left on
for more than 10 minutes when the ignition is in LOCK.
This will help prevent the battery from running down.
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Accessory Power Outlet(s)
Accessory power outlets can be used to connect
auxiliary electrical equipment, such as a cellular
telephone or CB radio.
Your vehicle may have one outlet located inside the
storage bin below the climate control system, one outlet
inside the center oor console and two outlets on the
rear of the center oor console.
The outlet located inside the storage bin below the
climate control system can only use equipment that
does not exceed 15 amperes.
Notice:Leaving electrical equipment on for
extended periods will drain the battery. Always
turn off electrical equipment when not in use
and do not plug in equipment that exceeds the
maximum
15 ampere rating.
There may also be an accessory power outlet located
in the rear of the vehicle near the liftgate. To use
an accessory power outlet, remove the protective cap.
When not in use, always cover the accessory power
outlet with the protective cap.If your vehicle is the SUT model, there is an accessory
power outlet in the rear cargo area on the passenger
side of the vehicle.
Notice:Adding any electrical equipment to your
vehicle may damage it or keep other components
from working as they should. The repairs would not
be covered by your warranty. Do not use equipment
exceeding maximum amperage rating of 20 amperes.
Check with your dealer/retailer before adding
electrical equipment.
Certain power accessory plugs may not be compatible
to the accessory power outlets and could result in
blown vehicle or adapter fuses. If you experience
a problem, see your dealer/retailer for additional
information on the accessory power plugs.
The accessory power outlets are powered, even
when the ignition is in LOCK/OFF. Continuing to use
power outlets while the ignition is in LOCK/OFF
may cause the vehicle’s battery to run down.
Notice:Improper use of the power outlet can cause
damage not covered by your warranty. Do not
hang any type of accessory or accessory bracket
from the plug because the power outlets are
designed for accessory power plugs only.
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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 Trip odometer.
See “Trip Odometer” underDIC Operation and
Displays (Using DIC Buttons) on page 3-49or
DIC Operation and Displays (Using Trip Odometer
Reset Stem) on page 3-54for more information.
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.
Trip Odometer
The trip odometer can tell you how far your vehicle has
been driven since you last set the trip odometer to zero.
Press the trip stem to toggle between the trip odometer
and the regular odometer. Holding the trip stem for
approximately one second while the trip odometer is
displayed will reset it.
To display the odometer reading with the ignition off,
press the trip stem.
Tachometer
Your tachometer displays the engine speed in
revolutions per minute (rpm).
Safety Belt Reminders
Safety Belt Reminder Light
When the engine is started, 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.
This chime and light is repeated if the driver remains
unbuckled and the vehicle is in motion. If the driver’s
belt is already buckled, neither the chime nor the
light will come on.
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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 3-56
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.
Voltmeter Gage
When your engine is
not running, but the
ignition is on, this gage
shows the battery’s
state of charge in
DC volts.
When the engine is running, the gage shows the
condition of the charging system. The charging system
regulates voltage based on the state of the battery
for improved fuel economy and battery life. The gage
may transition from a higher to lower or a lower to
higher reading, this is normal. Readings between
the low and high warning zones indicate the normal
operating range. The gage may also read low during
the fuel economy mode, this is normal.
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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 full power.
If there is a problem with the battery charging system,
this light will come on or the SERVICE BATTERY
CHARGING SYSTEM DIC message will display.
SeeDIC Warnings and Messages on page 3-56
andCharging System Light on page 3-37for
more information.
Brake System Warning Light
With the ignition on, the brake system warning
light will come on when you set the parking brake.
If you try to drive with the parking brake engaged,
a chime will sound when the vehicle speed is
greater than 5 mph (8 km/h).Your vehicle’s hydraulic brake system is divided into
two parts. If one part is not 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.
This light may also come on due to low brake uid.
SeeBrakes on page 5-36for more information.
This light should come on briey when you turn the
ignition key to RUN. If it does not come on then,
have it xed so it will be ready to warn you if there
is a problem.United StatesCanada
3-38

{CAUTION:
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
have pulled off the road and stopped carefully,
have the vehicle towed for service.
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 may go closer to the oor.
It may take longer to stop. If the light is still on, have
the vehicle towed for service. SeeTowing Your
Vehicle on page 4-51.
Antilock Brake System
Warning Light
For vehicles with
the Antilock Brake
System (ABS), this
light will come on
briey when you
start the engine.
That is normal. If the light does not come on then,
have it xed so it will be ready to warn you if there
is a problem.
If the ABS light stays on, turn the ignition off, if the light
comes on when you are driving, stop as soon as it is
safely possible and turn the ignition off. Then start the
engine again to reset the system. If the ABS light still
stays on, or comes on again while you are driving,
your vehicle needs service. If the regular brake system
warning light is not on, you still have brakes, but you do
not have antilock brakes. If the regular brake system
warning light is also on, you do not have antilock
brakes and there is a problem with your regular brakes.
SeeBrake System Warning Light on page 3-38
For vehicles with a Driver Information Center (DIC),
seeDIC Warnings and Messages on page 3-56for
all brake related DIC messages.
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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 3-56for more
information.
Stop and check your tires as soon as it is safe to
do so. If underinated, inate to the proper pressure.
SeeTires on page 5-55for 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 5-62for more information.
3-41

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.
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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.
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 5-7. The diagnostic
system can determine if the fuel cap has been 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.
3-43