2008 HUMMER H2 cooling

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 1-4for additional information.Laws in some communities may restrict the use of
remote starters. For example, some laws may require a
person using the remote start to have the vehicle in
view when doing so. Check local regulations for
any requirements on remote starting of vehicles.
Do not use the remote start feature if your vehicle is
low on fuel. Your vehicle may run out of fuel.
The RKE transmitter with the remote start button,
provides an increased range of operation. However, the
range may be less while the vehicle is running. As a
result, you may need to be closer to your vehicle to turn
it off, than you were to turn it on.
There are other conditions which can affect the
performance of the transmitter, seeRemote Keyless
Entry (RKE) System on page 2-4for additional
information.
2-8

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 2-43.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, do the following:
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, do the following:
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 2-43.The Midgate
®allows you to extend the length of your
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, do the following:
1. Fold the rear seats forward. SeeSplit Folding Rear
Seat on page 1-8. 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 3-4for
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

Climate Controls
Dual Automatic Climate Control
System
The heating, cooling, and ventilation in your vehicle
can be controlled with this system. Your vehicle also
has a ow-through ventilation system described later
in this section.
Different climate control settings can be selected for
the driver and passengers.
Driver’s Side Temperature Control
The driver’s side temperature buttons are used to
adjust the temperature of the air coming through the
system on the driver’s side. The temperature can
be adjusted even if the system is turned off. This is
possible since outside air will always ow through
the system as the vehicle is moving forward unless
it is set to recirculation mode. See “Recirculation”
later in this section.
Press the + or−buttons to increase or decrease
the cabin temperature. The driver side temperature
display will show the temperature setting decreasing
or increasing.
3-22

2. Set the driver’s and passenger’s 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’s or
passenger’s temperature buttons to adjust the
temperature setting as necessary. If you choose the
temperature setting of 60°F (15°C), the system
will remain at the maximum cooling setting. If you
choose the temperature setting of 90°F (32°C),
the system will remain at the maximum heat setting.
Choosing either maximum setting will not cause
the vehicle to heat or cool any faster.
Be careful not to 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 your 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.
O(On/Off):Press this button to turn off the climate
control system. Outside air will still enter the vehicle,
and will be 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 you adjust the
air delivery mode or temperature settings with the
system off, the display will illuminate briey to show
you the settings and then return off. Press the on/off
button or the up down arrows on the fan switch,
the defrost button, AUTO button, or the air conditioning
button to turn the system on when it is off.
3-24

StabiliTrak®Indicator Light
If equipped, this
warning light should
come on briey when
the engine is started.
If the warning light does not come on then, have it xed
so it will be ready to warn you if there is a problem.
If it stays on, or comes on when you are driving,
there may be a problem with your StabiliTrak
®system
and your vehicle may need service. When this warning
light is on, the system is off and will not limit wheel
spin. Adjust your driving accordingly.
This light will also ash when the StabiliTrak
®system
is active.
If the StabiliTrak
®system warning light comes on
and stays on for an extended period of time when
the system is turned on, your vehicle needs service.
SeeStabiliTrak
®System on page 4-7for more
information.
Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
It also provides an indicator of how hard your vehicle
is working. During a majority of the operation, the gage
will read 210°F (100°C) or less. If you are 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 5-27.
United StatesCanada
3-40

DRIVER DOOR OPEN
This message displays and a chime sounds if the
driver door is not fully closed and the vehicle is in a
drive gear. Stop and turn off the vehicle, check the
door for obstructions, and close the door again.
Check to see if the message still appears on the DIC.
ENGINE HOT A/C (Air Conditioning)
TURNED OFF
This message displays when the engine coolant
becomes hotter than the normal operating temperature.
SeeEngine Coolant Temperature Gage on page 3-40.
To avoid added strain on a hot engine, the air
conditioning compressor automatically turns off.
When the coolant temperature returns to normal,
the air conditioning compressor turns back on.
You can continue to drive your vehicle.
If this message continues to appear, have the
system repaired by your dealer/retailer as soon
as possible to avoid damage to the engine.
ENGINE OVERHEATED IDLE ENGINE
Notice:If you drive your vehicle while the engine
is overheating, severe engine damage may occur.
If an overheat warning appears on the instrument
panel cluster and/or DIC, stop the vehicle as soon
as possible. SeeEngine Overheating on page 5-27
for more information.
This message displays when the engine coolant
temperature is too hot. Stop and allow the vehicle to
idle until it cools down. SeeEngine Coolant
Temperature Gage on page 3-40.
SeeOverheated Engine Protection Operating Mode
on page 5-28for information on driving to a safe place
in an emergency.
ENGINE POWER IS REDUCED
This message displays and a chime sounds when
the cooling system temperature gets too hot and the
engine further enters the engine coolant protection
mode. SeeEngine Overheating on page 5-27for
further information.
3-57

Driving in Mud, Sand, Snow, or Ice
When you drive in mud, snow, or sand, your wheels
will not get good traction. You cannot accelerate
as quickly, turning is more difficult, and you will need
longer braking distances.
It is best to use a low gear when you are in mud — the
deeper the mud, the lower the gear. In really deep
mud, the idea is to keep your vehicle moving so you do
not get stuck. Be careful to keep mud from building
up and washing onto the engine cooling system.
When you drive on sand, you will sense a change in
wheel traction. But it will depend upon how loosely
packed the sand is. On loosely packed sand, such as
on beaches or sand dunes, your tires will tend to
sink into the sand. This has an effect on steering,
accelerating, and braking. Drive at a reduced speed
and avoid sharp turns or abrupt maneuvers.Hard packed snow and ice offer the worst tire traction.
On these surfaces, it is very easy to lose control.
On wet ice, for example, the traction is so poor that you
will have difficulty accelerating. And if you do get
moving, poor steering and difficult braking can cause
you to slide out of control.
{CAUTION:
Driving on frozen lakes, ponds, or rivers can
be dangerous. Underwater springs, currents
under the ice, or sudden thaws can weaken
the ice. Your vehicle could fall through the ice
and you and your passengers could drown.
Drive your vehicle on safe surfaces only.
4-30