light HUMMER H3 2007 Repair Manual

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 314.
186

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.
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 318.
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.
187

Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel.
SeeGasoline Octane on page 316. 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.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.
188

Oil Pressure Light
{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.The light will come on
when you turn your
key to ON or START.
It goes off once you start your engine. That is
a check to be sure the light works. If it does not
come on, be sure to have it xed so it will be
there to warn you if something goes wrong.
When the light comes on and stays on, it means
that oil is not owing through the engine properly.
The vehicle could be low on oil and it might
have some other system problem. SeeEngine Oil
on page 323and “OIL” underDIC Warnings
and Messages on page 196for more information.
189

Security Light
This light will come on
briey when you turn
the key to START.
The light will stay on
until the engine starts.
If the ignition is turned on, and the light ashes,
the Passlock
®system has entered a tamper
mode. If the vehicle fails to start, seePasslock®
on page 100.
If the ignition is turned on, but the engine is not
running, the light should be on solid.
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 98for
additional information regarding the security light.
Cruise Control Light
This light comes on
whenever you set the
cruise control.
The light goes out when the cruise control is
turned off. SeeCruise Control on page 159for
more information.
Highbeam On Light
This light comes
on whenever
the high-beam
headlamps are on.
SeeHeadlamp High/Low-Beam Changer
on page 157for more information.
190

DIC Warnings and Messages
Messages are displayed on the DIC to notify the
driver that the status of the vehicle has changed
and that some action may be needed by the driver
to correct the condition. Multiple messages may
appear one after another. The messages are
displayed for four seconds each.
Some messages may not require immediate
action, but you should press and release the trip
odometer reset stem to acknowledge that you
received the messages and to clear them from the
display. Each message must be acknowledged
individually.
Some messages cannot be cleared from the DIC
display because they are more urgent. These
messages require action before they can be
cleared. You should take any messages that
appear on the display seriously and remember
that clearing the messages will only make
the messages disappear, not correct the problem.
The following are the possible messages that can
be displayed and some information about them.
AC (Air Conditioning) OFF
This message displays when the engine coolant
temperature is too high and the air conditioning in
your vehicle needs to be turned off. SeeEngine
Overheating on page 338andClimate Control
System on page 170for more information.
This message displays along with the ENG HOT
message.
ABS (Anti-Lock Brake System) FAULT
This message displays if there is a problem
with the Anti-Lock Brake System (ABS). Check the
ABS as soon as possible and have your vehicle
serviced by your dealer. SeeBrakes on page 347
andAnti-Lock Brake System Warning Light on
page 183for more information. Press and release
the reset stem to acknowledge the message
and clear it from the display.
196

BRAKES
This message displays if there is a problem with
the brakes. Check the brakes as soon as possible
and have your vehicle serviced by your dealer.
SeeBrakes on page 347andBrake System
Warning Light on page 182for more information.
Press and release the reset stem to acknowledge
the message and clear it from the display.
CHANGE OIL
This message displays when the oil needs to be
changed. Check the oil in your vehicle as soon
as possible and have your vehicle serviced by
your dealer. SeeEngine Oil on page 323
andScheduled Maintenance on page 429for
more information. Press and release the reset
stem to acknowledge the message and clear
it from the display.
DOORS
This message displays when one or more of
the doors is ajar. Check all the doors on your
vehicle to make sure they are closed. The
message clears from the display after all of
the doors are closed.
ENG (Engine) HOT
This message displays when the engine coolant
temperature is hot. Check the engine coolant
temperature gage. SeeEngine Coolant
Temperature Gage on page 185. Have your
vehicle serviced by your dealer as soon as
possible if you suspect the engine is overheating.
SeeEngine Overheating on page 338for more
information.
FLUID
This message displays if the brake uid is low.
Check the brake uid as soon as possible
and have your vehicle serviced by your dealer.
SeeBrakes on page 347for more information.
Press and release the reset stem to acknowledge
the message and clear it from the display.
197

FUEL CAP
This message displays if the vehicle’s fuel cap is
either off or loose. Pull over as soon as possible
and check to see if the fuel cap is secure. You may
also see the check engine light on the instrument
panel cluster. If the check engine light does
come on when the fuel cap was loose, it may take
a few driving trips before the light turns off. See
Malfunction Indicator Lamp on page 186for more
information if the light still remains on. Press
and release the reset stem to acknowledge the
message and clear it from the display.
LOW FUEL
This message displays if the level of fuel in the
vehicle is low. Also check the fuel gage. See
Fuel Gage on page 191for more information.
Rell the fuel tank as soon as possible.
LOW TIRE
This message displays if a low tire pressure is
detected in any of the vehicle’s tires. Press
and release the reset stem to acknowledge the
message and clear it from the display. The
message appears at each ignition cycle until the
tires are inated to the correct ination pressure.
SeeTires on page 367andInation - Tire
Pressure on page 375for more information on
tires and the correct ination pressures.
OIL
This message displays when the oil pressure is
low. SeeOil Pressure Light on page 189and
Engine Oil on page 323for more information.
PARK BRK (Brake)
This message displays when the parking brake
is set. SeeParking Brake on page 116and
Brake System Warning Light on page 182for
more information. The message clears from the
display after the parking brake is released or
by pressing and releasing the reset stem.
198

REDUCED POWER
This message 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.
Press and release the reset stem to acknowledge
the message and clear it from the display.
SERV (Service) 4WD
(Four-Wheel Drive)
This message displays when there is a problem
with the transfer case control system. Check
the transfer case on your vehicle and have
it serviced by your dealer. SeeFull-Time
Four-Wheel Drive on page 111for more
information about the transfer case. Press and
release the reset stem to acknowledge the
message and clear it from the display.
SERV (Service) TPM
(Tire Pressure Monitor)
This message displays if any of the tire monitor
sensors have malfunctioned, if the tire monitor
sensors have not been programmed, or if
the recommended tire pressures are not
programmed. The tire pressure light also ashes
for one minute and then turns on solid until
the condition goes away or the system is serviced.
SeeTire Pressure Light on page 185. Press
and release the reset stem to acknowledge the
message and clear it from the display. This
message appears at each ignition cycle until the
system is serviced. See your dealer for service.
SeeTire Pressure Monitor System on page 376
for more information.
SERV (Service) VEH (Vehicle)
This message displays if your vehicle needs
service. Have your vehicle serviced by your dealer
as soon as possible.
199

SERVICE CHARG (Charge)
SYS (System)
This message displays if there is a problem
with the battery charging system. Under certain
conditions, the battery warning light may also turn
on in the instrument panel cluster. SeeBattery
Warning Light on page 181. The battery will not be
charging at an optimal rate and the vehicle will
lose the ability to enter the fuel economy mode.
The vehicle is safe to drive, however have
the electrical system checked by your dealer.
Press and release the reset stem to acknowledge
the message and clear it from the display.
SERVICE STAB (Stability)
SYS (System)
This message displays if there is a problem
with the StabiliTrak®system. Have your vehicle
serviced by your dealer. SeeStabiliTrak®System
on page 244for more information.
STAB (Stability) SYS (System) OFF
This message displays when the StabiliTrak®
system is turned off. SeeStabiliTrak®System
on page 244for more information.
TRAC (Traction) OFF
This message along with the traction off light
displays when the Traction Control System (TCS)
is turned off by pressing the TCS button. See
Traction Off Light on page 184andTraction
Control System (TCS) on page 241for more
information.
TRACTION FAILED
This message displays if there is a problem with
the Traction Control System (TCS). Check
the TCS as soon as possible and have your
vehicle serviced by your dealer. SeeTraction
Control System (TCS) on page 241for more
information. Press and release the reset stem to
acknowledge the message and clear it from
the display.
TURN SIGNAL
This message displays when the turn signal is
on for about 0.75 miles (1.2 km) of travel. Press
and release the reset stem to acknowledge
the message and clear it from the display.
200