check engine light CHEVROLET IMPALA 2007 9.G Owners Manual

Changes or modications to this system by other
than an authorized service facility could void
authorization to use this equipment.
PASS-Key
®III+ uses a radio frequency
transponder in the key that matches a decoder in
your vehicle.
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 398.Ifthe
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/retailer 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/retailer or a
locksmith who can service PASS-Key
®III+ to have
keys made and programmed to the system.
109

Warning Lights, Gages, and
Indicators
This part describes the warning lights and
gages on your vehicle. The pictures help to
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 the 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 the details show on the next few pages,
some warning lights come on briey when you
start the engine just to let you know they are
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 is a problem with your vehicle.
When one of the warning lights comes on and
stays on as 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 vehicle’s warning lights
and gages. They can be 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 190for more information.
174

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
181

Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
If the gage pointer moves towards the “H”
(United States) or the shaded in thermostat
(Canada), it means that your engine coolant has
overheated. If you have been operating your
vehicle under normal driving conditions, you should
pull off the road, stop your vehicle and turn off
the engine as soon as possible.
SeeEngine Overheating on page 323for more
information.
Tire Pressure Light
This light comes on
briey when you turn
the ignition to RUN.
This light will also come on when one or more of
your tires are signicantly underinated.
A CHECK TIRE PRESSURE message in the
Driver Information Center (DIC) will accompany
the light. SeeDIC Warnings and Messages
on page 199for more information.
Stop and check your tires as soon as it is safe to
do so. If underinated, inate to the proper
pressure. SeeTires on page 351for more
information.
United StatesCanada
184

This light will ash for approximately 60 seconds
and then stay on if a problem is detected with
the Tire Pressure Monitor system.
SeeTire Pressure Monitor System on page 360
for more information.
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 beindicated 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, the emission controls
might not work as well, your vehicle’s fuel
economy might not be as good, and the engine
might not run as smoothly. This could lead
to costly repairs that might 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 296.
185

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
possibleIf 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 302.
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.
186

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 298. 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.
187

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.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.
188

CHECK TIRE PRESSURE
This message displays when the tire pressure in
one of the tires needs to be checked. This message
also displays 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 the Tire Loading Information label.
SeeTires on page 351,Loading Your Vehicle on
page 277, andInation - Tire Pressure on
page 359. 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 191. If the tire
pressure is low, the low tire pressure warning light
comes on. SeeTire Pressure Light on page 184.
DRIVER DOOR OPEN
This message displays when the driver’s door is
not closed properly. When this message appears,
make sure that the driver’s door is closed
completely.
ENGINE HOT A/C
(Air Conditioning) OFF
This message displays when the engine coolant
becomes hotter than the normal operating
temperature. To avoid added strain on a hot engine,
the air conditioning compressor is automatically
turned off. When the coolant temperature returns to
normal, the A/C operation automatically resumes.
You can continue to drive your vehicle. If this
message continues to appear, have the system
repaired by your dealer as soon as possible to
avoid compressor damage.
201

SERVICE BATTERY CHARGING
SYSTEM
This message displays when there is a problem
with the generator and battery charging systems.
Driving with this problem could drain the 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
dealer immediately.
SERVICE BRAKE SYSTEM
This message displays when service is required
on the brake system. Have the brake system
serviced by your dealer as soon as possible.
The brake system warning light also appears on
the instrument panel cluster when this message
appears on the DIC. SeeBrake System Warning
Light on page 181.
SERVICE POWER STEERING
This message displays when a problem is
detected with the power steering system. When
this message is displayed, you may notice that the
effort required to steer the vehicle increases or
feels heavier, but you will still be able to steer the
vehicle. Have your vehicle serviced by your
dealer immediately.
SERVICE THEFT SYSTEM
This message displays when there is a problem
with the theft-deterrent system programmed in the
key. A fault has been detected in the system
which means that the system is disabled and it is
not protecting the vehicle. The vehicle usually
restarts; however, you may want to take the
vehicle to your dealer before turning off the engine.
SeePASS-Key
®III+ Operation on page 109for
more information.
205