brakes HUMMER H2 2009 Owners Manual

To rock the vehicle back and forth to get out of snow,
ice, or sand without damaging the transmission, seeIf
Your Vehicle is Stuck in Sand, Mud, Ice, or Snow on
page 4-39.
N (Neutral):In this position, the engine does not
connect with the wheels. To restart the engine when
the vehicle is already moving, use N (Neutral) only.
Also, use N (Neutral) when the vehicle is being towed.
{CAUTION:
Shifting into a drive gear while the engine is
running at high speed is dangerous. Unless your
foot is rmly on the brake pedal, the vehicle could
move very rapidly. You could lose control and hit
people or objects. Do not shift into a drive gear
while the engine is running at high speed.
Notice:Shifting out of P (Park) or N (Neutral) with
the engine running at high speed may damage the
transmission. The repairs would not be covered by
the vehicle warranty. Be sure the engine is not
running at high speed when shifting the vehicle.D (Drive):This position is for normal driving. It provides
the best fuel economy. If you need more power for
passing, and you are:
Going less than about 35 mph (55 km/h), push the
accelerator pedal about halfway down.
Going about 35 mph (55 km/h) or more, push the
accelerator all the way down.
By doing this, the vehicle shifts down to the next gear
and has more power.
D (Drive) can be used when towing a trailer, carrying a
heavy load, driving on steep hills, or for off-road driving.
You may want to shift the transmission to a lower gear
selection if the transmission shifts too often.
Downshifting the transmission in slippery road conditions
could result in skidding, see Skidding underLoss of
Control on page 4-13.
M (Manual Mode):This position lets the driver select
the range of gears appropriate for current driving
conditions. If the vehicle has this feature, see Driver
Shift Control (DSC) later in this section.
Notice:Spinning the tires or holding the vehicle in
one place on a hill using only the accelerator pedal
may damage the transmission. The repair will not be
covered by the vehicle warranty. If you are stuck, do
not spin the tires. When stopping on a hill, use the
brakes to hold the vehicle in place.
2-33

2 (Second):This position reduces vehicle speed
without using the brakes. Use 2 (Second) on hills.
It can help control vehicle speed as you go down steep
mountain roads, but then you may also want to use
the brakes off and on.
1 (First):This position reduces vehicle speed without
using the brakes. Use it for major/severe downgrades
and off-road driving where the vehicle would otherwise
accelerate due to steepness of grade.
When you shift to 2 (Second) or 1 (First) it provides
the lowest gear appropriate to your current road speed
and continues to downshift as the vehicle slows,
eventually downshifting to the selected gear.
The vehicle has a shift stabilization feature that adjusts
the transmission shifting to the current driving conditions
in order to reduce rapid upshifts and downshifts. This shift
stabilization feature is designed to determine, before
making an upshift, if the engine will be able to maintain
vehicle speed by analyzing things such as vehicle speed,throttle position and vehicle load. If the shift stabilization
feature determines that a current vehicle speed cannot be
maintained, the transmission does not upshift and instead
holds the current gear. In some cases, this may appear to
be a delayed shift, however the transmission is operating
normally.
The transmission uses adaptive shift controls that
compares key shift parameters to pre-programmed
ideal shifts stored in the transmission’s computer.
The transmission constantly makes adjustments to
improve vehicle performance according to how the
vehicle is being used, such as with a heavy load or
when the temperature changes. During this adaptive
shift control process, shifting may feel different as the
transmission determines the best settings.
When temperatures are very cold, the Hydra-Matic
®
6L80 automatic transmission’s gear shifting may
be delayed providing more stable shifts until the engine
warms up. Shifts may be more noticeable with a cold
transmission. This difference in shifting is normal.
2-34

Cruise Control
{CAUTION:
Cruise control can be dangerous where you cannot
drive safely at a steady speed. So, do not use the
cruise control on winding roads or in heavy traffic.
Cruise control can be dangerous on slippery roads.
On such roads, fast changes in tire traction can
cause excessive wheel slip, and you could lose
control. Do not use cruise control on slippery roads.
With cruise control, a speed of about 25 mph (40 km/h)
or more can be maintained without keeping your foot
on the accelerator. This can really help on long trips.
Cruise control does not work at speeds below about
25 mph (40 km/h).
When the brakes are applied, cruise control is
turned off.
If the vehicle has the StabiliTrak
®system or Traction
Control system (TCS) and begins to limit wheel spin
while you are using cruise control, the cruise control
automatically disengages. SeeStabiliTrak
®System on
page 4-6orTraction Control System (TCS) on page 4-9.
When road conditions allow the cruise control to be safely
uses again, it can be turned back on.The cruise control buttons
are located on the left side
of the steering wheel.
T(On/Off):Press to turn the system on or off.
The indicator light on the button turns on when cruise
control is on and turns off when cruise control is off.
+ RES (Resume/Accelerate):Press to make the
vehicle accelerate or resume to a previously set speed.
SET−(Set/Coast):Press to set the speed or make
the vehicle decelerate.
[(Cancel):Press to cancel cruise control without
erasing the set speed from memory.
3-12

Reducing Speed While Using Cruise
Control
To reduce the vehicle’s speed while using cruise
control:
Press and hold the SET– button on the steering
wheel until the desired lower speed is reached,
then release it.
To slow down in small amounts, press the
SET– button on the steering wheel briey. Each time
this is done, the vehicle goes about 1 mph (1.6 km/h)
slower.
Passing Another Vehicle While Using
Cruise Control
Use the accelerator pedal to increase the vehicle’s
speed. When you take your foot off the pedal, the
vehicle will slow down to the previously set cruise speed.
Using Cruise Control on Hills
How well the cruise control will work on hills depends
upon the vehicle’s speed, load, and the steepness of the
hills. When going up steep hills, you might have to step
on the accelerator pedal to maintain the vehicle’s speed.
When going downhill, you might have to brake or shift to
a lower gear to keep the vehicle’s speed down. When the
brakes are applied the cruise control turns off.
Ending Cruise Control
There are three ways to end cruise control:
Step lightly on the brake pedal.
Press the[button on the steering wheel.
Press theTbutton on the steering wheel.
Erasing Speed Memory
The cruise control set speed memory is erased when
the cruise control or the ignition is turned off.
3-14

Brake System Warning Light
With the ignition on, the brake system warning light
comes on when the parking brake is set. If the vehicle is
driven with the parking brake engaged, a chime sounds
when the vehicle speed is greater than 5 mph (8 km/h).
The vehicle’s hydraulic brake system is divided into
two parts. If one part is not working, the other part
can still work and stop the vehicle. For good braking,
both parts need to be working well.
If the warning light comes on and a chime sounds there
could be a brake problem. Have the brake system
inspected right away.
This light can also come on due to low brake uid.
SeeBrakes on page 5-38for more information.This light comes on briey when the ignition key is
turned to ON/RUN. If it does not come on then, have it
xed so it is ready to warn if there is a problem.
{CAUTION:
The brake system might not be working properly if
the brake system warning light is on. Driving with
the brake system warning light on can lead to a
crash. If the light is still on after the vehicle has
been pulled off the road and carefully stopped,
have the vehicle towed for service.
If the light comes on while driving, pull off the road and
stop carefully. The pedal might be harder to push or
might go closer to the oor. It can take longer to stop.
If the light is still on, have the vehicle towed for service.
SeeTowing Your Vehicle on page 4-50.
United States
Canada
3-37

Antilock Brake System (ABS)
Warning Light
For vehicles with
the Antilock Brake
System (ABS), this light
comes on briey when
the engine is started.
If it does not, have the vehicle serviced by your
dealer/retailer. If the system is working normally the
indicator light then goes off.
If the ABS light stays on, turn the ignition off. If the
light comes on while 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 stays on, or
comes on again while driving, the vehicle needs service.
If the regular brake system warning light is not on, the
vehicle still has brakes, but not antilock brakes. If the
regular brake system warning light is also on, the vehicle
does not have antilock brakes and there is a problem with
the regular brakes. SeeBrake System Warning Light on
page 3-37.
For vehicles with a Driver Information Center (DIC),
seeDIC Warnings and Messages on page 3-56for all
brake related DIC messages.
StabiliTrak®Indicator Light
For vehicles with the
StabiliTrak®system, this
light comes on briey while
starting the engine.
If it does not, have the vehicle serviced by your
dealer/retailer. If the system is working normally the
indicator light then goes off.
If the light comes on and stays on while driving, there
could be a problem with the StabiliTrak
®system and the
vehicle might need service. When this warning light is
on, the StabiliTrak
®system is off and does not limit
wheel spin.
The light ashes if the system is active and is working
to assist the driver with directional control of the
vehicle in difficult driving conditions.
SeeStabiliTrak
®System on page 4-6for more
information.
3-38

SERVICE BRAKES SOON
This message displays if there is a problem with the
brake system. If this message appears, stop as soon
as possible and turn off the vehicle. Restart the vehicle
and check for the message on the DIC display. If the
message is still displayed or appears again when
you begin driving, the brake system needs service.
See your dealer/retailer.
SERVICE STABILITRAK
This message displays when there may be a problem
with the StabiliTrak®system. If you see this message, try
to reset the system. Stop; turn off the engine for at least
15 seconds; then start the engine again. If this message
still comes on, it means there is a problem. You should
see your dealer/retailer for service. The vehicle is safe to
drive, however, you do not have the benet of StabiliTrak,
so reduce your speed and drive accordingly.
SERVICE SUSPENSION SYSTEM
On some models, this message displays if a problem
occurs with the suspension system. If this message
appears, stop as soon as possible and turn off
the vehicle. Restart the vehicle and check for the
message on the DIC display. If the message is still
displayed, or appears again when you begin driving,
there is a problem with the air suspension system.
See your dealer/retailer for service.
SERVICE THEFT DETERRENT SYSTEM
This message displays when there is a problem with
the theft-deterrent system. The vehicle may or may not
restart so you may want to take the vehicle to your
dealer/retailer before turning off the engine. See
PASS-Key
®III+ Electronic Immobilizer Operation
on page 2-26for more information.
SERVICE TIRE MONITOR SYSTEM
On vehicles with the Tire Pressure Monitor
System (TPMS), this message displays if a part
on the TPMS is not working properly. The tire pressure
light also ashes and then remains on during the same
ignition cycle. SeeTire Pressure Light on page 3-39.
Several conditions may cause this message to appear.
SeeTire Pressure Monitor Operation on page 5-66for
more information. If the warning comes on and stays
on, there may be a problem with the TPMS. See your
dealer/retailer.
SERVICE TRACTION CONTROL
This message displays when there is a problem with
the Traction Control System (TCS). When this message
displays, the system will not limit wheel spin. Adjust
your driving accordingly. See your dealer/retailer
for service. SeeTraction Control System (TCS) on
page 4-9andStabiliTrak
®System on page 4-6for
more information.
3-61

Drunk Driving
{CAUTION:
Drinking and then driving is very dangerous. Your
reexes, perceptions, attentiveness, and judgment
can be affected by even a small amount of alcohol.
You can have a serious — or even fatal — collision
if you drive after drinking. Do not drink and drive or
ride with a driver who has been drinking. Ride home
in a cab; or if you are with a group, designate a
driver who will not drink.
Death and injury associated with drinking and driving is
a global tragedy.
Alcohol affects four things that anyone needs to drive a
vehicle: judgment, muscular coordination, vision, and
attentiveness.
Police records show that almost 40 percent of all motor
vehicle-related deaths involve alcohol. In most cases,
these deaths are the result of someone who was drinking
and driving. In recent years, more than 17,000 annual
motor vehicle-related deaths have been associated with
the use of alcohol, with about 250,000 people injured.For persons under 21, it is against the law in every
U.S. state to drink alcohol. There are good medical,
psychological, and developmental reasons for
these laws.
The obvious way to eliminate the leading highway
safety problem is for people never to drink alcohol and
then drive.
Medical research shows that alcohol in a person’s
system can make crash injuries worse, especially
injuries to the brain, spinal cord, or heart. This means
that when anyone who has been drinking — driver
or passenger — is in a crash, that person’s chance of
being killed or permanently disabled is higher than if the
person had not been drinking.
Control of a Vehicle
The following three systems help to control the vehicle
while driving — brakes, steering, and accelerator. At
times, as when driving on snow or ice, it is easy to ask
more of those control systems than the tires and road can
provide. Meaning, you can lose control of the vehicle.
SeeTraction Control System (TCS) on page 4-9.
Adding non-dealer/non-retailer accessories can affect
vehicle performance. SeeAccessories and Modifications
on page 5-3.
4-3

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