cooling HUMMER H2 2007 Owners Manual

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 197.
If you have air outlets on or under the
instrument panel, open them all the
way. SeeEngine Exhaust on page 137.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 108.
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 108.
104

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
®
CAUTION: (Continued)
CAUTION: (Continued)
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 197.
If you have air outlets on or under the
instrument panel, open them all the
way. SeeEngine Exhaust on page 137.
The Midgate
®allows you to extend the length of
your vehicle’s cargo area into the cab.
105

Ashtray(s) and Cigarette Lighter
If your vehicle has an ashtray, it is removable and
ts into the front cupholder. Pull up on the
ashtray door to open it.
Notice:If you put papers, pins, or other
ammable items in the ashtray, hot cigarettes
or other smoking materials could ignite
them and possibly damage your vehicle. Never
put ammable items in the ashtray.
To remove the ashtray, pull it out from the
console. To reinstall the ashtray, slide it back to
the original position.
To use the cigarette lighter, if equipped, push it in
all the way, and let go. When it’s ready, it will
pop back out by itself.
Notice:Holding a cigarette lighter in while it
is heating will not allow the lighter to back
away from the heating element when it is hot.
Damage from overheating may occur to the
lighter or heating element, or a fuse could be
blown. Do not hold a cigarette lighter in
while it is heating.
Climate Controls
Dual Automatic Climate Control
System
With this system, you can control the heating,
cooling and ventilation in your vehicle.
You can select different climate control settings for
the driver and passengers.
197

Automatic Operation
AUTO (Automatic):When automatic operation is
active the system will control the inside
temperature, the air delivery, and the fan speed.
Use the steps below to place the entire system in
automatic mode:
1. Press the AUTO button.
When AUTO is selected, the display will
change to show the current driver’s set
temperature, delivery mode and fan speed.
Press the AUTO button again within
ve seconds to display the passenger’s set
temperature.
If the driver and passenger’s temperature
settings are not the same, the opposite side
temperature setting will be displayed for
an additional ve seconds. To make the
passenger’s temperature the same as
the driver’s press and hold the AUTO button
for about four seconds.
When auto is selected, the air conditioning
operation and air inlet will be automatically
controlled. The air conditioning compressor will
run when the outside temperature is over about
40°F (4°C). The air inlet will normally be set to
outside air. If it’s hot outside, the air inlet mayautomatically switch to recirculate inside air to
help quickly cool down your vehicle. The light
on the button will illuminate in recirculation.
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. Turn the
driver’s or passenger’s side temperature knob
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 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.
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.
199

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 418.
Transmission Temperature Gage
Your vehicle has a transmission temperature gage.
When your ignition is on, the gage shows the
temperature of the transmission uid. The normal
operating range is from 180°F (82°C) to about
200°F (93°C).
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213

ENGINE COOLANT HOT
This message displays if the cooling system
temperature gets hot. Turn off the air conditioning.
If the message is still on, or if the engine coolant
temperature gage continues to rise, pull the vehicle
over when it is safe to do so. SeeEngine
Coolant Temperature Gage on page 213for more
information. Stop the vehicle and let the engine
idle in PARK (P) for a few minutes to allow
the coolant to reach a safe temperature. This
message clears when the coolant temperature
drops to a safe operating temperature. Press any
of the DIC buttons, or the trip stem, to
acknowledge this message and clear it from the
DIC display.
ENGINE OVERHEATED
This message displays and a chime sounds if the
engine cooling system reaches unsafe
temperatures for operation. Stop and turn off the
vehicle as soon as it is safe to do so to avoid
severe damage. This message clears when the
engine has cooled to a safe operating temperature.
FUEL LEVEL LOW
This message displays and a chime sounds if the
fuel level is low. Refuel as soon as possible.
Press any of the DIC buttons, or the trip stem, to
acknowledge this message and clear it from
the DIC display. This message also clears itself
after 10 seconds. The low fuel light near the
fuel gage still remains on in either case. SeeLow
Fuel Warning Light on page 221,Fuel Gage on
page 221, andFuel on page 394for more
information.
KEYFOB X BATTERY LOW
This message displays if a Remote Keyless
Entry (RKE) transmitter battery is low. Replace
the battery in the transmitter. See “Battery
Replacement” underRemote Keyless Entry (RKE)
System Operation on page 97. Press any of the
DIC buttons, or the trip stem, to acknowledge this
message and clear it from the DIC display.
228

REDUCED ENGINE POWER
This message displays when the cooling system
temperature gets too hot and the engine further
enters the engine coolant protection mode.
SeeEngine Overheating on page 418for further
information.
This message may also display when the vehicle
determines that there is a problem with the
electronic throttle control. See your dealer
for service.
This message also displays when the vehicle’s
engine power is reduced. Reduced engine power
can affect the vehicle’s ability to accelerate.
If this message is on, but there is no reduction in
performance, proceed to your destination. The
performance may be reduced the next time the
vehicle is driven. The vehicle may be driven at a
reduced speed while this message is on, but
acceleration and speed may be reduced. Anytime
this message stays on, the vehicle should be taken
to your dealer for service as soon as possible.
REPLACE LIFTGATE FUSE (SUV)
This message displays if the liftgate lock
malfunctions and/or the liftgate fuse blows. For
more information on fuses, seeInstrument Panel
Fuse Block on page 504andUnderhood Fuse
Block on page 507.
If the message returns after replacing the fuse,
see your dealer for service.
RIGHT REAR DOOR AJAR
This message displays and a chime sounds if the
passenger’s side rear 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. Press any of
the DIC buttons, or the trip stem, to acknowledge
this message and clear it from the DIC display.
230

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.
336

After Off-Road Driving
Remove any brush or debris that has collected
on the underbody, chassis, or under the hood.
These accumulations can be a re hazard.
After operation in mud or sand, have the brake
linings cleaned and checked. These substances
can cause glazing and uneven braking. Check the
engine and oil coolers for mud accumulation.
Thoroughly and carefully clean these devices to
allow proper cooling. Check the body structure,
steering, suspension, wheels, tires, and exhaust
system for damage. Also, check the fuel lines and
cooling system for any leakage.
Your vehicle will require more frequent service
due to off-road use. See the Maintenance
Schedule for additional information.
Assist Steps
Your vehicle may be equipped with removable
side steps.
Remove the steps prior to off-roading to give your
vehicle more ground clearance and to prevent
damage to the vehicle from the side steps
dragging and/or catching on obstacles.
Notice:Do not drive off-road with the side
steps attached to your vehicle. You can damage
the side steps and/or your vehicle’s frame if
they get caught or drag against an obstacle.
This damage would not be covered by your
vehicle’s warranty. Always remove the side
steps prior to any off-road driving.
338

Hill and Mountain Roads
Driving on steep hills or mountains is different
from driving in at or rolling terrain.If you drive regularly in steep country, or if you are
planning to visit there, here are some tips that
can make your trips safer and more enjoyable.
SeeOff-Road Driving on page 317for information
about driving off-road.
Keep your vehicle in good shape. Check all
uid levels and also the brakes, tires, cooling
system, and transmission. These parts
can work hard on mountain roads.
{CAUTION:
If you do not shift down, your brakes
could get so hot that they would not work
well. You would then have poor braking or
even none going down a hill. You could
crash. Shift down to let your engine assist
your brakes on a steep downhill slope.
351