2009 HUMMER H2 cooling

To replace the battery:
1. Separate the transmitter with a at, thin object
inserted into the notch on the side.
2. Remove the old battery. Do not use a metal object.
3. Insert the new battery, positive side facing down.
Replace with a CR2032 or equivalent battery.
4. Snap the transmitter back together.
Remote Vehicle Start
The remote start feature allows you to start the engine
from outside of the vehicle. It may also start up the
vehicle’s heating or air conditioning systems and rear
window defogger. Normal operation of the system
will return after the key is turned to the ON/RUN
position.
During a remote start, the climate control system
will default to a heating mode during colder outside
temperatures and a cooling mode during warmer
outside temperatures.
During a remote start, the rear window defogger
and heated mirrors, if equipped, will turn on during
colder outside temperatures and will shut off when
the key is turned to ON/RUN.
During a remote start, the heated seats will turn on
during colder outside temperatures and will shut
off when the key is turned to ON/RUN. SeeHeated
Seats on page 1-6for additional information.
2-7

Liftgate (SUV)
{CAUTION:
It can be dangerous to drive with the liftgate open
because carbon monoxide (CO) gas can come
into your vehicle. You can not see or smell CO.
It can cause unconsciousness and even death.
If you must drive with the liftgate open or if
electrical wiring or other cable connections must
pass through the seal between the body and the
liftgate:
Make sure all other windows are shut.
Turn the fan on your heating or cooling
system to its highest speed and select the
control setting that will force outside air into
your vehicle. SeeDual Automatic Climate
Control System on page 3-22.
If you have air outlets on or under the
instrument panel, open them all the way.
SeeEngine Exhaust on page 2-45.To lock and unlock the liftgate, use any of the power
door lock switches or the Remote Keyless Entry (RKE)
transmitter.
To open the liftgate:
1. Move the spare tire carrier out of the way.
See “Opening the Spare Tire Carrier” under
Tailgate/Spare Tire Carrier on page 2-16.
2. Pull the handle located in the center of the door.
To close the liftgate:
1. Pull the liftgate down until it latches.
2. Move the spare tire carrier back into place.
See “Closing the Spare Tire Carrier” under
Tailgate/Spare Tire Carrier on page 2-16.
2-13

Midgate®(SUT)
{CAUTION:
It can be dangerous to drive with the cargo area
covered and the tailgate and the Midgate®open
because carbon monoxide (CO) gas can come
into your vehicle. You can not see or smell CO.
It can cause unconsciousness and even death.
If you must drive with the cargo covers on and the
tailgate and Midgate
®open or if electrical wiring or
other cable connections must pass through the
seal between the body and the Midgate
®:
Make sure all windows are shut.
Turn the fan on your heating or cooling
system to its highest speed on the setting that
brings in outside air. This will force outside air
into your vehicle. SeeDual Automatic Climate
Control System on page 3-22.
If you have air outlets on or under the
instrument panel, open them all the way.
SeeEngine Exhaust on page 2-45.
The Midgate
®allows you to extend the length of the
vehicle’s cargo area into the cab.
Lowering the Midgate
The Midgate window must be completely lowered for
the Midgate®to be lowered. See “Midgate®Window”
underPower Windows on page 2-20.
Both the Midgate and the Midgate window can be
lowered while the ignition is in either ON/RUN or
ACC/ACCESSORY, or while in Retained Accessory
Power (RAP) mode. SeeRetained Accessory
Power (RAP) on page 2-29for more information.
To lower the Midgate:
1. Fold the rear seats forward. SeeSplit Folding Rear
Seat on page 1-11. The front seats may have to be
moved forward slightly.
2.
K(Midgate Window):Press the bottom part
of this switch to lower the Midgate window.
SeeInstrument Panel Overview on page 3-4
for the location of this switch.
The window can also be operated using the global
express-down button. See “Global Glass Feature”
underPower Windows on page 2-20.
2-14

Tow/Haul Mode
The vehicle has a tow/haul mode. The tow/haul mode
adjusts the transmission shift pattern to reduce shift
cycling, providing increased performance, vehicle
control, and transmission cooling while towing or
hauling heavy loads.
Press the button located on the instrument panel to the
right of the steering wheel to turn tow/haul on or off. While
tow/haul is on, a light on the instrument panel cluster
comes on.
SeeTow/Haul Mode Light on page 3-44for more
information.
Also see “Tow Haul Mode” underTowing a Trailer on
page 4-55for more information.
Grade Braking
Grade Braking is only active while the Tow/Haul Mode is
selected and you are not in the Range Selection Mode.
See “Tow/Haul Mode listed previously andAutomatic
Transmission Operation on page 2-32for more
information on the Range Selection Mode. Grade Braking
assists in maintaining desired vehicle speeds when
driving on downhill grades by automatically implementing
a shift schedule that utilizes the engine and transmission
to slow the vehicle. This reduces wear on the braking
system and increases control of the vehicle. Grade
Braking monitors vehicle speed, acceleration, engine
torque and brake pedal usage. Using this information,
it detects when the truck is on a downhill grade and the
driver desires to slow the vehicle by pressing the brake.
Also seeTowing a Trailer on page 4-55for more
information.
2-36

Electric Power Management
The vehicle has Electric Power Management (EPM) that
estimates the battery’s temperature and state of charge.
It then adjusts the voltage for best performance and
extended life of the battery.
When the battery’s state of charge is low, the voltage is
raised slightly to quickly bring the charge back up. When
the state of charge is high, the voltage is lowered slightly
to prevent overcharging. If the vehicle has a voltmeter
gage or a voltage display on the Driver Information
Center (DIC), you may see the voltage move up or down.
This is normal. If there is a problem, an alert will be
displayed.
The battery can be discharged at idle if the electrical
loads are very high. This is true for all vehicles. This is
because the generator (alternator) may not be spinning
fast enough at idle to produce all the power that is
needed for very high electrical loads.
A high electrical load occurs when several of the
following are on, such as: headlamps, high beams, fog
lamps, rear window defogger, climate control fan at
high speed, heated seats, engine cooling fans, trailer
loads, and loads plugged into accessory power outlets.EPM works to prevent excessive discharge of the
battery. It does this by balancing the generator’s output
and the vehicle’s electrical needs. It can increase
engine idle speed to generate more power, whenever
needed. It can temporarily reduce the power demands
of some accessories.
Normally, these actions occur in steps or levels, without
being noticeable. In rare cases at the highest levels of
corrective action, this action may be noticeable to the
driver. If so, a Driver Information Center (DIC) message
might be displayed, such as BATTERY SAVER ACTIVE,
BATTERY VOLTAGE LOW, or LOW BATTERY. If this
message is displayed, it is recommended that the driver
reduce the electrical loads as much as possible. SeeDIC
Warnings and Messages on page 3-56.
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/OFF. This helps to prevent the battery
from running down.
3-19

Climate Controls
Dual Automatic Climate Control
System
The heating, cooling, and ventilation in the vehicle can
be controlled with this system. The vehicle also has
a ow-through ventilation system described later in
this section.
A. Fan Control
B. AUTO
C. Defrost
D. Recirculation
E. REARF. Air Delivery Mode
Control
G. Driver Side
Temperature ControlH. Display
I. Power Button
J. Rear Window
DefoggerK. Air Conditioning
L. PASS (Passenger
Setting)
M. Passenger Side
Temperature ControlO(On/Off):Press to turn the climate control
system on or off. Outside air still enters the vehicle,
and is directed to the oor. This direction can be
changed by pressing the mode button. Recirculation
can be selected once you have selected vent or bi-level
mode. The temperature can also be adjusted using
either temperature button. If the air delivery mode or
temperature settings are adjusted with the system off,
the display illuminates briey to show the settings and
then returns to off. The system can be turned back on
by pressing either
O,D,C,#, the defrost or the
AUTO button.
3-22

2. Set the driver and passenger temperature.
To nd your comfort setting, start with a 74°F (23°C)
temperature setting and allow about 20 minutes for
the system to regulate. Use the driver or passenger
temperature buttons to adjust the temperature setting
as necessary. If a temperature setting of 60°F (15°C)
is chosen, the system remains at the maximum
cooling setting. If a temperature setting of 90°F
(32°C) is chosen, the system remains at the
maximum heat setting. Choosing either maximum
setting will not cause the vehicle to heat or cool
any faster.
Do not cover the solar sensor located on the top of
the instrument panel near the windshield. This sensor
regulates air temperature based on sun load and also
turns on the headlamps. For more information on the
solar sensor, see “Sensors” later in this section.
To avoid blowing cold air in cold weather, the system
will delay turning on the fan until warm air is available.
The length of delay depends on the engine coolant
temperature. Pressing the fan switch will override this
delay and change the fan to a selected speed.Manual Operation
DC(Fan Control):Press these buttons to increase or
decrease the fan speed.
Pressing either fan button while in automatic control
places the fan under manual control. The fan setting
remains displayed and the AUTO light turns off. The air
delivery mode remains under automatic control.
HG(Air Delivery Mode Control):Press these buttons
to change the direction of the airow in the vehicle.
Repeatedly press either button until the desired mode
appears on the display. Pressing either mode button
while the system is off changes the air delivery mode
without turning the system on. Pressing either mode
button while in automatic control places the mode
under manual control.
The air delivery mode setting is displayed and the
AUTO light turns off. The fan remains under automatic
control.
3-24

Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
It also provides an indicator of how hard the vehicle is
working. During a majority of the operation, the gage
reads 210°F (100°C) or less. If the vehicle is pulling a
load or going up hills, it is normal for the temperature to
uctuate and approach the 250°F (122°C) mark. If the
gage reaches the 260°F (125°C) mark, it indicates that
the cooling system is working beyond its capacity.
SeeEngine Overheating on page 5-33.
Tire Pressure Light
For vehicles with a tire
pressure light, this light
comes on briey when
the engine is started.
It provides information about tire pressures and the
Tire Pressure Monitoring System.
When the Light is On Steady
This indicates that one or more of the tires is signicantly
underinated.
A tire pressure message in the Driver Information
Center (DIC), can accompany the light. SeeDIC
Warnings and Messages on page 3-56for more
information. Stop and check the tires as soon as it is
safe to do so. If a tire is underinated, inate to the
proper pressure. SeeTires on page 5-57for more
information. United States
Canada
3-39