warning light HUMMER H2 2009 Owner's Manual

Braking
SeeBrake System Warning Light on page 3-37.
Braking action involves perception time and reaction
time. Deciding to push the brake pedal is perception
time. Actually doing it is reaction time.
Average reaction time is about three-fourths of a
second. But that is only an average. It might be less
with one driver and as long as two or three seconds or
more with another. Age, physical condition, alertness,
coordination, and eyesight all play a part. So do alcohol,
drugs, and frustration. But even in three-fourths of a
second, a vehicle moving at 60 mph (100 km/h) travels
66 feet (20 m). That could be a lot of distance in an
emergency, so keeping enough space between
the vehicle and others is important.And, of course, actual stopping distances vary greatly
with the surface of the road, whether it is pavement
or gravel; the condition of the road, whether it is
wet, dry, or icy; tire tread; the condition of the brakes;
the weight of the vehicle; and the amount of brake force
applied.
Avoid needless heavy braking. Some people drive
in spurts — heavy acceleration followed by heavy
braking — rather than keeping pace with traffic. This is a
mistake. The brakes might not have time to cool between
hard stops. The brakes will wear out much faster with a
lot of heavy braking. Keeping pace with the traffic and
allowing realistic following distances eliminates a lot of
unnecessary braking. That means better braking and
longer brake life.
Adding non-dealer/non-retailer accessories can affect
vehicle performance. SeeAccessories and Modifications
on page 5-3.
4-4

Antilock Brake System (ABS)
This vehicle has the Antilock Brake System (ABS), an
advanced electronic braking system that helps prevent a
braking skid.
When the engine is started and the vehicle begins to
drive away, ABS checks itself. A momentary motor
or clicking noise might be heard while this test is going
on. This is normal.
If there is a problem with
the ABS, this warning light
stays on. SeeAntilock
Brake System (ABS)
Warning Light on
page 3-38.Let us say the road is wet and you are driving safely.
Suddenly, an animal jumps out in front of you. You slam
on the brakes and continue braking. Here is what
happens with ABS:
A computer senses that the wheels are slowing down.
If one of the wheels is about to stop rolling, the computer
will separately work the brakes at each front wheel
and at both rear wheels.
ABS can change the brake pressure to each wheel, as
required, faster than any driver could. This can help
the driver steer around the obstacle while braking hard.
As the brakes are applied, the computer keeps
receiving updates on wheel speed and controls braking
pressure accordingly.
Remember: ABS does not change the time needed to get
a foot up to the brake pedal or always decrease stopping
distance. If you get too close to the vehicle in front of you,
there will not be enough time to apply the brakes if that
vehicle suddenly slows or stops. Always leave enough
room up ahead to stop, even with ABS.
4-5

Traction Control Operation
The traction control system is part of the
StabiliTrak system. Traction control limits wheel
spin by reducing engine power to the wheels (engine
speed management) and by applying brakes to
each individual wheel (brake-traction control) as
necessary.
The traction control system is enabled automatically
when the vehicle is started. It will activate and the
StabiliTrak light will ash if it senses that any of the
wheels are spinning or beginning to lose traction while
driving. If the traction control is turned off, only the
brake-traction control portion of traction control will work.
The engine speed management will be disabled. In this
mode, engine power is not reduced automatically and the
driven wheels can spin more freely. This can cause the
brake-traction control to activate constantly.
Notice:If the wheel(s) of one axle is allowed to
spin excessively while the StabiliTrak, ABS
and brake warning lights and any relevant DIC
messages are displayed, the transfer case could bedamaged. The repairs would not be covered by the
vehicle warranty. Reduce engine power and do
not spin the wheel(s) excessively while these lights
and messages are displayed.
The traction control system may activate on dry or
rough roads or under conditions such as heavy
acceleration while turning or abrupt upshifts/downshifts
of the transmission. When this happens, a reduction
in acceleration may be noticed, or a noise or vibration
may be heard. This is normal.
If cruise control is being used when StabiliTrak activates,
the cruise control automatically disengages. The
cruise control can be re-engaged when road conditions
allow. SeeCruise Control on page 3-12.
StabiliTrak may also turn off automatically if it determines
that a problem exists with the system. If the problem does
not clear itself after restarting the vehicle, see your
dealer/retailer for service.
4-8

Driving in Rain and on Wet Roads
Rain and wet roads can reduce vehicle traction
and affect your ability to stop and accelerate. Always
drive slower in these types of driving conditions
and avoid driving through large puddles and
deep-standing or owing water.
{CAUTION:
Wet brakes can cause crashes. They might not
work as well in a quick stop and could cause
pulling to one side. You could lose control of the
vehicle.
After driving through a large puddle of water or a
car/vehicle wash, lightly apply the brake pedal until
the brakes work normally.
Flowing or rushing water creates strong forces.
Driving through owing water could cause your
vehicle to be carried away. If this happens, you
and other vehicle occupants could drown. Do not
ignore police warnings and be very cautious about
trying to drive through owing water.
Hydroplaning
Hydroplaning is dangerous. Water can build up under
your vehicle’s tires so they actually ride on the
water. This can happen if the road is wet enough and
you are going fast enough. When your vehicle is
hydroplaning, it has little or no contact with the road.
There is no hard and fast rule about hydroplaning.
The best advice is to slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet weather driving tips
include:
Allow extra following distance.
Pass with caution.
Keep windshield wiping equipment in good shape.
Keep the windshield washer uid reservoir lled.
Have good tires with proper tread depth. SeeTires
on page 5-57.
Turn off cruise control.
4-34

To use this feature, ensure that the following conditions
are met:
The engine must be running.
All doors must be fully closed. The suspension will
not raise or lower if a door is open.
The vehicle speed must be less than 40 mph
(64 km/h). The system will not activate otherwise.
Press the height control button to raise the rear of the
vehicle.
A light in the button will begin to ash as the rear of
the vehicle rises. Once the extended height has been
reached (this may take up to a minute), the warning light
will stop ashing and will stay lit while the vehicle is at the
extended height.
To lower the vehicle to the normal ride height, press the
button again. The light in the button will ash as the
suspension lowers. When the light in the button stops
ashing and goes out, the suspension has reached
the normal ride height.
This feature will lower the vehicle to the normal height if
vehicle speed exceeds 40 mph (64 km/h).
This feature may also be used when ascending,
descending or cresting a steep hill to help prevent the
rear bumper from dragging on the base of the hill
or prevent the vehicle from grounding out (high
centering) on the crest of the hill.
Do not use this feature when towing a trailer.
Electronically Controlled Air
Suspension System
With this feature, the electronically controlled air
suspension keeps the rear of the vehicle level under all
load conditions. The system maintains the vehicle at the
currently selected ride height. There are two ride heights:
Normal Ride Height and Extended Ride Height. The
Extended Ride Height feature is only available if the
vehicle speed is below 40 mph (64 km/h). If the vehicle is
at Extended Ride Height and the speed exceeds 40 mph
(64 km/h), the system will automatically return the vehicle
to Normal Ride Height.
The activation and
deactivation of the
Extended Ride Height
feature is controlled by
this switch on the
instrument panel.
4-53

The system includes a compressor, two height sensors
and two air springs supporting the vehicle.
The system is activated when the engine is started
and deactivated when the ignition is returned to OFF.
The engine must be running for the rear of the vehicle to
be raised and the doors must be closed to enable a
transition between Normal Ride Height and Extended
Ride Height.
The compressor may be heard while the system is
active and the release of air similar to a hissing sound
may also be heard. This is normal.
Load leveling will not function normally with the inater
hose attached to the inator outlet. Remove the
hose from the outlet when it is not in use. See
Accessory Inflator on page 5-78.Overload and Overheat Protection
Overload protection is designed to protect the air
suspension system and is an indication to the driver that
the vehicle is overloaded.
If the rear suspension remains at a low height, the rear
axle load has exceeded GAWR (Gross Axle Weight
Rating). When the overload protection mode is activated,
the compressor operates for about 30 seconds to one
minute without raising the vehicle depending on the
amount of overload. This will continue each time the
ignition is turned on until the rear axle load is reduced
below GAWR. The system may reactivate without cycling
the ignition if some of the excess load is removed.
If the total rear GAWR (Gross Axle Weight Rating) is
reached, the suspension may be slightly less than level.
This is normal and does not mean there is a problem
with the air suspension.
In some instances the compressor may stop working
due to being overheated. This is normal. In the instance
of an abnormal overheat condition though the
compressor will stop working and the SERVICE
SUSPENSION SYSTEM will be displayed on the DIC.
SeeDIC Warnings and Messages on page 3-56for
more information.
4-54

Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. The vehicle could be damaged. Avoid
making very sharp turns while trailering.
When turning with a trailer, make wider turns than
normal. Do this so the trailer will not strike soft shoulders,
curbs, road signs, trees or other objects. Avoid jerky or
sudden maneuvers. Signal well in advance.
Turn Signals When Towing a Trailer
The arrows on the instrument panel ash whenever
signaling a turn or lane change. Properly hooked up, the
trailer lamps also ash, telling other drivers the vehicle
is turning, changing lanes or stopping.
When towing a trailer, the arrows on the instrument panel
ash for turns even if the bulbs on the trailer are burned
out. For this reason you may think other drivers are
seeing the signal when they are not. It is important to
check occasionally to be sure the trailer bulbs are still
working.
Driving On Grades
Reduce speed and shift to a lower gearbeforestarting
down a long or steep downgrade. If the transmission is
not shifted down, the brakes might have to be used so
much that they would get hot and no longer work well.
Vehicles can tow in D (Drive). Shift the transmission to
a lower gear if the transmission shifts too often under
heavy loads and/or hilly conditions.
The tow/haul mode may be used if the transmission
shifts too often. SeeTow/Haul Mode Light on page 3-44.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If the engine is
turned off immediately after towing at high altitude on
steep uphill grades, the vehicle may show signs similar to
engine overheating. To avoid this, let the engine run while
parked, preferably on level ground, with the automatic
transmission in P (Park) for a few minutes before turning
the engine off. If the overheat warning comes on, see
Engine Overheating on page 5-33.
4-65

The TIGHTEN GAS CAP message displays on the
Driver Information Center (DIC) if the fuel cap is
not properly installed. SeeDIC Warnings and Messages
on page 3-56for more information.
{CAUTION:
If a re starts while you are refueling, do not
remove the nozzle. Shut off the ow of fuel by
shutting off the pump or by notifying the station
attendant. Leave the area immediately.
Notice:If you need a new fuel cap, be sure to get
the right type. Your dealer/retailer can get one
for you. If you get the wrong type, it may not t
properly. This may cause the malfunction indicator
lamp to light and may damage the fuel tank and
emissions system. SeeMalfunction Indicator Lamp
on page 3-40.
Filling a Portable Fuel Container
{CAUTION:
Never ll a portable fuel container while it is in the
vehicle. Static electricity discharge from the
container can ignite the fuel vapor. You can be
badly burned and the vehicle damaged if this
occurs. To help avoid injury to you and others:
Dispense fuel only into approved containers.
Do not ll a container while it is inside a
vehicle, in a vehicle’s trunk, pickup bed, or on
any surface other than the ground.
CAUTION: (Continued)
5-10

5. With the coolant surge tank pressure cap off, start
the engine and let it run until you can feel the upper
radiator hose getting hot. Watch out for the
engine cooling fan.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge tank
until the level reaches the FULL COLD mark.
6. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
7. Verify coolant level after engine is shut off and the
coolant is cold. If necessary, repeat coolant ll
procedure steps 1 through 7.
Engine Coolant
The cooling system in the vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in the vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended life coolant.
The following explains the cooling system and how to add
coolant when it is low. If you have a problem with engine
overheating, seeEngine Overheating on page 5-33.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®can
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at the rst maintenance
service after each 30,000 miles (50 000 km) or
24 months, whichever occurs rst. Any repairs would
not be covered by the vehicle warranty. Always use
DEX-COOL
®(silicate-free) coolant in the vehicle.
5-31

Brake Wear
This vehicle has disc brakes. Disc brake pads have
built-in wear indicators that make a high-pitched warning
sound when the brake pads are worn and new pads
are needed. The sound can come and go or be heard all
the time the vehicle is moving, except when applying
the brake pedal rmly.
{CAUTION:
The brake wear warning sound means that soon
the brakes will not work well. That could lead to an
accident. When the brake wear warning sound is
heard, have the vehicle serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates can cause a brake
squeal when the brakes are rst applied or lightly applied.
This does not mean something is wrong with the brakes.Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts in
the proper sequence to torque specications in
Capacities and Specifications on page 5-117.
Brake linings should always be replaced as complete
axle sets.
Brake Pedal Travel
See your dealer/retailer if the brake pedal does not
return to normal height, or if there is a rapid increase in
pedal travel. This could be a sign that brake service
might be required.
Brake Adjustment
Every brake stop, the disc brakes adjust for wear.
5-40