check engine light CHEVROLET IMPALA 2006 9.G Owners Manual

PASS-Key®III+ Operation
Your vehicle has PASS-Key®III+ (Personalized
Automotive Security System) theft-deterrent system.
PASS-Key
®III+ is a passive theft-deterrent system.
This means you do not have to do anything special to
arm or disarm the system. It works when you transition
the key to RUN, ACCESSORY or START from the
OFF position.
When the PASS-Key
®III+ system senses that someone
is using the wrong key, it prevents the vehicle from
starting. Anyone using a trial-and-error method to start
the vehicle will be discouraged because of the high
number of electrical key codes.
If the engine does not start and the security light on the
instrument panel cluster comes on when trying to
start the vehicle, the key may have a damaged
transponder. Turn the ignition off and try again.If the engine still does not start, and the key appears to
be undamaged, try another ignition key. At this time,
you may also want to check the fuse, seeFuses
and Circuit Breakers on page 5-94. If the engine still
does not start with the other key, your vehicle needs
service. If your vehicle does start, the rst key may be
faulty. See your dealer who can service the
PASS-Key
®III+ to have a new key made. In an
emergency, contact Roadside Assistance.
It is possible for the PASS-Key
®III+ decoder to learn
the transponder value of a new or replacement key.
Up to nine additional keys may be programmed for the
vehicle. The following procedure is for programming
additional keys only. If all the currently programmed
keys are lost or do not operate, you must see your
dealer or a locksmith who can service PASS-Key
®III+
to have keys made and programmed to the system.
See your dealer or a locksmith who can service
PASS-Key
®III+ to get a new key blank that is cut
exactly as the ignition key that operates the system.
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Warning Lights, Gages, and
Indicators
This part describes the warning lights and gages that
may be 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 may also have a Driver Information
Center (DIC) that works along with the warning lights
and gages. SeeDriver Information Center (DIC)
on page 3-39.
3-24

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.
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.
Brake System Warning Light
Your vehicle’s hydraulic brake system is divided into
two parts. If one part is not working, the other part can
still work and stop you. For good braking, though,
you need both parts working well.
If the warning light comes on, there is a brake problem.
Have your brake system inspected right away.
This light should come on briey when you turn the
ignition key to RUN. If it does not come on then, have it
xed so it will be ready to warn you if there is a problem.
United StatesCanada
3-30

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,
transaxle, 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 5-3.
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.
3-34

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 5-8.
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 5-5. 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.
3-35

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 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.
3-36

This light tells you there
could be a problem with
the engine oil pressure.
The light goes on when you turn your key to RUN 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 your engine properly. You could be
low on oil and you might have some other system
problem.Security Light
For information
regarding this light, see
Theft-Deterrent Systems
on page 2-17.
Fog Lamp Light
The fog lamp light will
come on when the fog
lamps are in use.
The light will go out when the fog lamps are turned off.
SeeFog Lamps on page 3-15for more information.
3-37

AUTOMATIC LIGHT CONTROL OFF
This message will display when the automatic
headlamps are turned off. SeeDaytime Running Lamps
(DRL)/Automatic Headlamp System on page 3-14for
more information.
AUTOMATIC LIGHT CONTROL ON
This message will display when the automatic
headlamps are turned on. SeeDaytime Running Lamps
(DRL)/Automatic Headlamp System on page 3-14for
more information.
CHANGE ENGINE OIL SOON
This message will display when service is required for
the vehicle. See your GM dealer. SeeEngine Oil
on page 5-17andScheduled Maintenance on page 6-4
for more information.
Acknowledging the CHANGE ENGINE OIL SOON
message will not reset the OIL LIFE REMAINING. That
must be done at the OIL LIFE screen under the
vehicle information menu. See “Oil Life” underDIC
Operation and Displays on page 3-39andEngine Oil
Life System on page 5-20.
CHECK TIRE PRESSURE
If your vehicle has a Tire Pressure Monitor (TPM)
system, this message will display when the tire pressure
in one of the tires needs to be checked. This message
will also display LEFT FRONT, RIGHT FRONT,
LEFT REAR, or RIGHT REAR to indicate which tire
needs to be checked. You can receive more than one
tire pressure message at a time. To read the other
messages that may have been sent at the same time,
press the set/reset button. If a tire pressure message
appears on the DIC, stop as soon as you can. Have the
tire pressures checked and set to those shown on
your Tire Loading Information Label. SeeTires
on page 5-54,Loading Your Vehicle on page 4-29, and
Ination - Tire Pressure on page 5-60. The DIC
display also shows the tire pressure values for the front
and rear tires by pressing the vehicle information
button. SeeDIC Operation and Displays on page 3-39.
If the tire pressure is low, the low tire pressure
warning light will come on. SeeTire Pressure Light
on page 3-33.
DRIVER DOOR OPEN
This message will display when the driver’s door is not
closed properly. When this message appears, you
should make sure that the driver’s door is closed
completely.
3-46

Anti-Lock Brake System (ABS)
Your vehicle may have the Anti-Lock Brake System
(ABS), an advanced electronic braking system that will
help prevent a braking skid.
If your vehicle has ABS,
this warning light on the
instrument panel
cluster will come on briey
when you start your
vehicle.
When you start your engine, or when you begin to drive
away, ABS will check itself. You may hear a momentary
motor or clicking noise while this test is going on,
and you may even notice that your brake pedal moves
or pulses a little. This is normal.Let us say the road is wet and you are driving safely.
Suddenly, an animal jumps out in front of you. You slam
on the brakes and continue braking. Here is what
happens with ABS:
A computer senses that wheels are slowing down.
If one of the wheels is about to stop rolling, the computer
will separately work the brakes at each front wheel
and at both rear wheels.
4-7

You can run the engine to keep warm, but be careful.
{CAUTION:
Snow can trap exhaust gases under your
vehicle. This can cause deadly CO (carbon
monoxide) gas to get inside. CO could
overcome you and kill you. You cannot see
it or smell it, so you might not know it is in
your vehicle. Clear away snow from around
the base of your vehicle, especially any that
is blocking your exhaust pipe. And check
around again from time to time to be sure
snow does not collect there.
Open a window just a little on the side of the
vehicle that is away from the wind. This will
help keep CO out.
Run your engine only as long as you must. This saves
fuel. When you run the engine, make it go a little
faster than just idle. That is, push the accelerator
slightly. This uses less fuel for the heat that you get
and it keeps the battery charged. You will need a
well-charged battery to restart the vehicle, and possibly
for signaling later on with your headlamps. Let the
heater run for a while.
4-27