2007 HUMMER H2 engine

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).
United StatesCanadaUnited StatesCanada
213

At approximately 265°F (130°C), the Driver
Information Center (DIC) will display a
TRANSMISSION HOT message and the
transmission will enter a transmission protection
mode. When the transmission enters the protection
mode, you may notice a change in the transmission
shifting patterns. The transmission will return to
normal shifting patterns when the transmission uid
temperature falls below 260°F (125°C).
If the transmission uid reaches temperatures of
approximately 275°F (135°C) or greater, the DIC
will display a TRANS HOT IDLE ENGINE warning
message and a chime will sound. Pull the vehicle
off the roadway when it is safe to do so. Set the
parking brake, place the transmission in PARK (P)
and allow the engine to idle until the transmission
temperature falls below 260°F (125°C). If the
transmission continues to operate above 265°F
(130°C), please contact your nearest dealer or the
GM Roadside Assistance Center.
SeeDriver Information Center (DIC) on page 222
for further information.Notice:If you drive your vehicle with the
transmission temperature gage above normal
operating range, you can damage the
transmission. This could lead to costly repairs
that would not be covered by your warranty.
Do not drive your vehicle while the
transmission temperature gage reading is
above normal. See your dealer for service.
The following situations can cause the
transmission to operate at higher temperatures:
Towing a trailer,
hot outside air temperatures,
hauling a large or heavy load,
low transmission uid level,
high transmission uid level,
restricted air ow to the radiator.
A temporary solution to hotter transmission
operating temperatures may be to let the
transmission cool down. If the transmission is
operated at higher temperatures on a frequent
basis, seeScheduled Maintenance on page 517
for the proper transmission maintenance intervals.
214

Malfunction Indicator Lamp
Check Engine Light
Your vehicle has a
computer which
monitors operation
of the fuel, ignition,
and emission
control systems.
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended
to assure that emissions are at acceptable
levels for the life of the vehicle, helping to produce
a cleaner environment. The check engine light
comes on to indicate that there is a problem and
service is required. Malfunctions often will be
indicated by the system before any problem is
apparent. This may prevent more serious damage
to your vehicle. This system is also designed to
assist your service technician in correctly
diagnosing any malfunction.Notice:If you keep driving your vehicle with
this light on, after awhile, your emission
controls may not work as well, your fuel
economy may not be as good, and your engine
may not run as smoothly. This could lead to
costly repairs that may not be covered by your
warranty.
Notice:Modications made to the engine,
transmission, exhaust, intake, or fuel system
of your vehicle or the replacement of the
original tires with other than those of the same
Tire Performance Criteria (TPC) can affect
your vehicle’s emission controls and may
cause this light to come on. Modications to
these systems could lead to costly repairs not
covered by your warranty. This may also
result in a failure to pass a required Emission
Inspection/Maintenance test. SeeAccessories
and Modifications on page 392.
215

This light should come on, as a check to show
you it is working, when the ignition is on and the
engine is not running. If the light does not
come on, have it repaired. This light will also
come on during a malfunction in one of two ways:
Light Flashing— A misre condition has
been detected. A misre increases vehicle
emissions and may damage the emission
control system on your vehicle. Diagnosis and
service may be required.
Light On Steady— An emission control
system malfunction has been detected on your
vehicle. Diagnosis and service may be
required.
If the Light is Flashing
The following may prevent more serious damage
to your vehicle:
Reducing vehicle speed
Avoiding hard accelerations
Avoiding steep uphill grades
If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible
If the light stops ashing and remains on steady,
see “If the Light Is On Steady” following.
If the light continues to ash, when it is safe to do
so, stop the vehicle. Find a safe place to park
your vehicle. Turn the key off, wait at least
10 seconds and restart the engine. If the light
remains on steady, see “If the Light Is On Steady”
following. If the light is still ashing, follow the
previous steps, and see your dealer for service as
soon as possible.
216

If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully
install the cap. SeeFilling the Tank on page 397.
The diagnostic system can determine if the
fuel cap has been left off or improperly installed.
A loose or missing fuel cap will allow fuel to
evaporate into the atmosphere. A few driving trips
with the cap properly installed should turn the
light off.
Did you just drive through a deep puddle of water?
If so, your electrical system may be wet. The
condition will usually be corrected when the
electrical system dries out. A few driving trips
should turn the light off.Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel.
SeeGasoline Octane on page 394. Poor fuel
quality will cause your engine not to run as
efficiently as designed. You may notice this as
stalling after start-up, stalling when you put
the vehicle into gear, misring, hesitation on
acceleration, or stumbling on acceleration. (These
conditions may go away once the engine is
warmed up.) This will be detected by the system
and cause the light to turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at
least one full tank of the proper fuel to turn the
light off.
If none of the above steps have made the light
turn off, your dealer can check the vehicle.
Your dealer has the proper test equipment and
diagnostic tools to x any mechanical or electrical
problems that may have developed.
217

Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have
or may begin programs to inspect the emission
control equipment on your vehicle. Failure to pass
this inspection could prevent you from getting a
vehicle registration.
Here are some things you need to know to help
your vehicle pass an inspection:
Your vehicle will not pass this inspection if the
check engine light is on or not working properly.
Your vehicle will not pass this inspection if
the OBD (on-board diagnostic) system determines
that critical emission control systems have not
been completely diagnosed by the system.
The vehicle would be considered not ready for
inspection. This can happen if you have recently
replaced your battery or if your battery has
run down. The diagnostic system is designed to
evaluate critical emission control systems
during normal driving. This may take several days
of routine driving. If you have done this and
your vehicle still does not pass the inspection for
lack of OBD system readiness, your dealer
can prepare the vehicle for inspection.
Oil Pressure Gage
The oil pressure gage shows the engine oil
pressure in psi (pounds per square inch) when the
engine is running. Canadian vehicles indicate
pressure in kPa (kilopascals).
Oil pressure may vary with engine speed, outside
temperature and oil viscosity, but readings
above the low pressure zone indicate the normal
operating range.
United StatesCanada
218

A reading in the low pressure zone may be
caused by a dangerously low oil level or some
other problem causing low oil pressure. Check
your oil as soon as possible. SeeEngine Oil on
page 404.
{CAUTION:
Do not keep driving if the oil pressure is
low. If you do, your engine can become so
hot that it catches re. You or others could
be burned. Check your oil as soon as
possible and have your vehicle serviced.
Notice:Lack of proper engine oil maintenance
may damage the engine. The repairs would
not be covered by your warranty. Always follow
the maintenance schedule in this manual for
changing engine oil.
Security Light
This light will come on
briey when you turn
the key toward START.
The light will stay on
until the engine starts.
If the light ashes, the Passlock
®system has
entered a tamper mode. If the vehicle fails to start,
seePasslock
®on page 118.
If the light comes on continuously while driving
and stays on, there may be a problem with
the Passlock
®system. Your vehicle will not be
protected by Passlock®, and you should see your
dealer.
Also, seeContent Theft-Deterrent on page 116for
additional information regarding the security light.
219

Fuel Gage
When the ignition is on, the fuel gage tells you
about how much fuel you have left in your tank.
The gage will rst indicate empty before you
are out of fuel, and you should get more fuel as
soon as possible.Here are some situations you may experience with
your fuel gage. None of these indicate a problem
with the fuel gage.
At the gas station, the fuel pump shuts off
before the gage reads full.
It takes a little more or less fuel to ll up than
the fuel gage indicated. For example, the
gage may have indicated the tank was half full,
but it actually took a little more or less than
half the tank’s capacity to ll the tank.
The gage goes back to empty when you turn
off the ignition.
Low Fuel Warning Light
The light next to the fuel gage will come on briey
when you are starting the engine.
This light comes on and a FUEL LEVEL LOW
message will appear on the Driver Information
Center when the fuel tank is low on fuel. To turn it
off, add fuel to the fuel tank. SeeFuel on
page 394andDIC Warnings and Messages on
page 226for more information.
United StatesCanada
221