check engine light HUMMER H2 2005 Owners Manual

While the alarm is set, the power door unlock switch is
not operational.
If the alarm does not sound when it should but the
headlamps ash, check to see if the horn works. The
horn fuse may be blown. To replace the fuse, see
Instrument Panel Fuse Block on page 5-103and
Underhood Fuse Block on page 5-107.
If the alarm does not sound or the headlamps do not
ash, the vehicle should be serviced by your dealer.
Passlock®
Your vehicle is equipped with the Passlock®
theft-deterrent system.
Passlock
®is a passive theft-deterrent system. Passlock®
enables fuel if the ignition lock cylinder is turned with
a valid key. If a correct key is not used or the ignition
lock cylinder is tampered with, the fuel system is
disabled and the vehicle will not start.
During normal operation, the security light will turn off
approximately ve seconds after the key is turned
to RUN.If the engine stalls and the security light ashes, wait
about 10 minutes until the light stops ashing before
trying to restart the engine. Remember to release
the key from START as soon as the engine starts.
If the engine does not start after three tries, the vehicle
needs service.
If the engine is running and the security light comes on,
you will be able to restart the engine if you turn the
engine off. However, your Passlock
®system is
not working properly and must be serviced by your
dealer. Your vehicle is not protected by Passlock
®at this
time. You may also want to check the fuse. See
Instrument Panel Fuse Block on page 5-103and
Underhood Fuse Block on page 5-107. See your dealer
for service.
In an emergency, call the Roadside Assistance Center.
SeeRoadside Assistance Program on page 7-6.
2-24

Off-Road Lamps
Notice:If you drive your vehicle through an
automatic car wash that does not have enough
clearance for any roof-mounted accessories (such
as off-road lamps or a roof basket) on your vehicle,
you can damage your vehicle. To avoid damaging
your vehicle in a car wash, remove any
roof-mounted accessories if you can, and do not
use an automatic car wash while roof-mounted
accessories are on your vehicle. SeeWashing Your
Vehicle on page 5-96for more information.
The off-road lamps, if equipped, provide auxiliary
lighting when your vehicle is used off road. These lamps
are not intended to be used in conjunction with, or in
place of, existing vehicle lighting. The lamps are not to
be used on any public street or highway and are to
be covered when not in use. Check your state and local
laws before installing or using any auxiliary lighting.
In some states it may be necessary to remove the roof
lamps when operating the vehicle on the highway.
The button for the off-road lamps is located in the
overhead console.
To use the lamps, be sure the engine is running.
Remove the covers from the lamps and press the button
to turn them on. Press the button again to turn them
off. An indicator light will glow near the button when the
lamps are on.Notice:Turning on the off-road lamps before
removing the lamp covers could damage the
off-road lamps and the covers. Always return the
lamps to the upright position and remove the covers
before turning on the off-road lamps.
The off-road lamps will remain on even after the ignition
is turned off. The off-road lamps button must be
pressed to turn them off.
Instrument Panel Brightness
The thumbwheel for this feature is located next to the
exterior lamps control.
D(Instrument Panel Lights):Turn the thumbwheel
up or down to brighten or dim the instrument panel
lights and the radio display. This will only work if
the headlamps or parking lamps are on.
To turn on the dome lamps, with the vehicle doors
closed, turn the thumbwheel all the way up.
3-16

Warning Lights, Gages, and
Indicators
This part describes the warning lights and gages on
your vehicle. The pictures will help you locate them.
Warning lights and gages can signal that something is
wrong before it becomes serious enough to cause
an expensive repair or replacement. Paying attention to
your warning lights and gages could also save you
or others from injury.
Warning lights come on when there may be or is a
problem with one of your vehicle’s functions. As you will
see in the details on the next few pages, some
warning lights come on briey when you start the
engine just to let you know they’re working. If you are
familiar with this section, you should not be alarmed
when this happens.Gages can indicate when there may be or is a problem
with one of your vehicle’s functions. Often gages
and warning lights work together to let you know when
there’s a problem with your vehicle.
When one of the warning lights comes on and stays on
when you are driving, or when one of the gages shows
there may be a problem, check the section that tells you
what to do about it. Please follow this manual’s advice.
Waiting to do repairs can be costly – and even
dangerous. So please get to know your warning lights
and gages. They’re a big help.
Your vehicle also has a message center that works
along with warning lights and gages. SeeDIC Warnings
and Messages on page 3-47.
3-26

Your instrument cluster is designed to let you know at a
glance how your vehicle is running. You’ll know how
fast you’re going, about how much fuel you have
and many other things you’ll need to know to drive safely
and economically.
Speedometer and Odometer
Your speedometer lets you see your speed in both
miles per hour (mph) and kilometers per hour (km/h).
Your vehicle’s odometer works together with the
driver information center. You can set a Trip A and Trip
B odometer. See “Trip Information” underDIC
Operation and Displays on page 3-44.
The odometer mileage can be checked without the
vehicle running. Simply press the trip stem on the
instrument panel cluster.
If your vehicle ever needs a new odometer installed, the
new one will be set to the correct mileage total of the
old odometer.
Tachometer
Your tachometer displays the engine speed in
revolutions per minute (rpm).Notice:If you operate the engine with the
tachometer in the shaded warning area, your vehicle
could be damaged, and the damages would not be
covered by your warranty. Do not operate the engine
with the tachometer in the shaded warning area.
Safety Belt Reminder Light
When the key is turned to RUN or START, a chime will
be provided for several seconds to remind people to
buckle their safety belts. The driver safety belt light will
also be provided and stay on for several seconds,
then it will ash for several more. You should buckle
your seat belt.
This chime and light will be
repeated if the driver
remains unbuckled and the
vehicle is in motion.
If the driver’s belt is buckled, neither the chime nor the
light will be provided.
3-28

{CAUTION:
If the airbag readiness light ever comes on
when you have turned off the airbag, it means
that something may be wrong with the airbag
system. The right front passenger’s airbag
could inate even though the switch is off. If
this ever happens, do not let anyone whom the
national government has identied as a
member of a passenger airbag risk group sit in
the right front passenger’s position (for
example, do not secure a rear-facing child
restraint in the right front passenger’s seat)
until you have your vehicle serviced. See
Airbag Off Switch on page 1-65, for more on
this, including important safety information.
Charging System Light
The charging system light
will come on briey when
you turn on the ignition,
but the engine is not
running, as a check to
show you it is working.
It should go out once the engine is running. If it stays
on, or comes on while you are driving, you may have a
problem with the charging system. It could indicate
that you have problems with a generator drive belt, or
another electrical problem. Have it checked right
away. Driving while this light is on could drain your
battery.
When this light comes on the DIC will also display the
battery not charging message. SeeDIC Warnings
and Messages on page 3-47.
If you must drive a short distance with the light on, be
certain to turn off all your accessories, such as the radio
and air conditioner.
3-31

Malfunction Indicator Lamp
Check Engine Light
Your vehicle is equipped
with 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.
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.
3-37

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 GM dealer can prepare the
vehicle for inspection.
3-39

CHARGING SYSTEM FAILURE
On some vehicles, if there is a problem with the
generator and battery charging system, this message
will appear on the DIC, a chime will sound and the
charging system light on the instrument panel cluster
will come on. SeeCharging System Light on page 3-31
for more information. Driving with this problem could
drain your battery. Turn off all unnecessary accessories.
Stop and turn off the vehicle as soon as it is safe to
do so. Have the electrical system checked by your
GM dealer immediately.
CHECK OIL LEVEL
If the oil level in the vehicle is low, this message will
appear on the DIC. Check the oil level and correct it as
necessary. You may need to let the vehicle cool or
warm up and cycle the ignition to be sure this message
will clear. Once the problem is corrected, pressing
any of the four DIC buttons or the trip odometer reset
stem will clear this message from the DIC display. This
message will clear itself after 10 seconds until the
next ignition cycle.
CHECK WASHER FLUID
If the washer uid level is low, this message will appear
on the DIC. Adding washer uid will clear the message.
Pressing any of the four DIC buttons or the trip
odometer reset stem will clear it from the DIC display.
This message will clear itself after 10 seconds until
the next ignition cycle.
DRIVER DOOR AJAR
If the driver’s door is not fully closed and the vehicle is in
a drive gear, this message will appear on the display and
you will hear a chime. Stop and turn off the vehicle, check
the door for obstacles, and close the door again. Check to
see if the message still appears on the DIC. Pressing any
of the four DIC buttons or the trip odometer reset stem
will clear the message from the DIC display.
ENGINE COOLANT HOT
If the cooling system temperature gets hot, this message
will appear in the DIC. Stop the vehicle and let the
engine idle in PARK (P) to allow the coolant to reach a
safe temperature. This message will clear when the
coolant temperature drops to a safe operating
temperature. Pressing any of the four DIC buttons or
the trip odometer reset stem will clear the message from
the DIC display.
3-48

ENGINE OVERHEATED
If the engine cooling system reaches unsafe
temperatures for operation, this message will appear in
the DIC and you will hear a chime. Stop and turn off
the vehicle as soon as it is safe to do so to avoid severe
damage. This message will clear when the engine
has cooled to a safe operating temperature.
FUEL LEVEL LOW
If the fuel level is low, this message will appear on the
DIC and you will hear a chime. Refuel as soon as
possible. Pressing any of the four DIC buttons or the
trip odometer reset stem will clear the message from the
DIC display. It will also clear itself after 10 seconds.
The low fuel light near the fuel gage will still remain on
in either case.
KEYFOB X BATTERY LOW
If a remote keyless entry transmitter battery is low, this
message will appear on the DIC. The battery needs
to be replaced in the transmitter. See “Battery
Replacement” underRemote Keyless Entry System
Operation on page 2-5. Pressing any of the four
DIC buttons or the trip odometer reset stem will clear
the message from the DIC display.
LEFT REAR DOOR AJAR
If the driver’s side rear door is not fully closed and the
vehicle is in a drive gear, this message will appear
on the display and you will hear a chime. Stop and turn
off the vehicle, check the door for obstacles, and
close the door again. Check to see if the message still
appears on the DIC. Pressing any of the four DIC
buttons or the trip odometer reset stem will clear the
message from the DIC display.
LOW COOLANT LEVEL
If your vehicle has a low coolant sensor and the engine
coolant level is low, this message will appear on the
DIC. Adding coolant will clear the message. This
message will clear itself after 10 seconds until the next
ignition cycle.
OIL LIFE RESET
This message will appear on the display for about
10 seconds after resetting the change engine oil
message.
3-49

SERVICE CHARGING SYSTEM
On some vehicles, if there is a problem with the battery
charging system, this message will appear on the
DIC. 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
you should have the electrical system checked by
your GM dealer. Pressing any of the four DIC buttons or
the trip odometer reset stem will clear the message
from the DIC display.
TIGHTEN FUEL CAP
If the vehicle’s fuel cap is not tightened properly, this
message may appear along with the check engine light
on the instrument panel cluster. SeeMalfunction Indicator
Lamp on page 3-37. Reinstall the fuel cap, making sure
to fully install the cap. SeeFilling Your Tank on page 5-7.
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 and message off.
TRACTION ACTIVE
When the traction control system has detected that any
of the vehicle’s wheels are slipping, the traction
control system will activate and this message will appear
on the DIC. SeeTraction Control System (TCS) on
page 4-9for more information.
TRANS HOT IDLE ENGINE
If the transmission uid gets hot, this message will
appear on the DIC along with a continuous chime.
Driving with the transmission uid temperature high can
cause damage to the vehicle. Stop the vehicle and
let it idle to allow the transmission to cool. This message
will clear and the chime will stop when the uid
temperature reaches a safe level.
3-52