2008 CADILLAC STS Owners Manual

If, after several seconds, both status indicator lights
remain on, or if there are no lights at all, there may
be a problem with the lights or the passenger sensing
system. See your dealer/retailer for service.
{CAUTION:
If the airbag readiness light in the instrument
panel cluster ever comes on and stays on,
it means that something may be wrong with
the airbag system. If this ever happens,
have the vehicle serviced promptly, because
an adult-size person sitting in the right front
passenger’s seat may not have the protection
of the airbag(s). SeeAirbag Readiness Light
on page 3-60for more on this, including
important safety information.
Charging System Light
This 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. A charging system
Driver Information Center (DIC) message may also
appear. SeeDIC Warnings and Messages on page 3-80
for more information. This light could indicate that
you have problems with a generator drive belt,
or another electrical problem. Have it checked right
away. 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.
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Brake System Warning Light
Your vehicle’s hydraulic brake system is divided into
two parts. If one part isn’t 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
engine on. If it does not come on then, have it xed so
it will be ready to warn you if there is a problem.When the ignition is on, the brake system warning light
will also come on when you set your parking brake.
The light will stay on if your parking brake does
not release fully. If it stays on after your parking brake
is fully released, it means you have a brake problem.
If the light comes on while you are driving, pull off
the road and stop carefully. You may notice that the
pedal is harder to push, or the pedal may go closer to
the oor. It may take longer to stop. If the light is still on,
have the vehicle towed for service. SeeTowing Your
Vehicle on page 4-31.
{CAUTION:
Your brake system may not be working
properly if the brake system warning light is
on. Driving with the brake system warning
light on can lead to an accident. If the light
is still on after you have pulled off the road
and stopped carefully, have the vehicle towed
for service. United StatesCanada
3-64

Antilock Brake System
Warning Light
For vehicles with the
Antilock Brake System
(ABS), this light will come
on briey when you
start the engine.
That is normal. If the light does not come on then, have it
xed so it will be ready to warn you if there is a problem.
If the ABS light stays on, turn the ignition off, if the light
comes on when you are driving, stop as soon as it
is safely possible and turn the ignition off. Then start
the engine again to reset the system. If the ABS light still
stays on, or comes on again while you are driving,
your vehicle needs service. If the regular brake system
warning light is not on, you still have brakes, but
you do not have antilock brakes. If the regular brake
system warning light is also on, you do not have antilock
brakes and there is a problem with your regular
brakes. SeeBrake System Warning Light on page 3-64
For vehicles with a Driver Information Center (DIC),
seeDIC Warnings and Messages on page 3-80for
all brake related DIC messages.
Traction Control System (TCS)
Warning Light
If the Traction Control
System (TCS) warning
light comes on and stays
on, there may be a
problem with the TCS.
The TCS warning light will come on briey when the
engine is started. If it does not come on then, have it
xed so it will be ready to warn you if there is a problem.
The light will also come on if you turn the TCS off using
the traction control on/off button located on the console.
If this light stays on or comes on while you are driving,
pull off the road as soon as possible and stop carefully.
Turn your engine off and then restart it. If the light still
stays on or comes back on again while you are driving,
your vehicle needs service. Have the TCS inspected as
soon as possible. SeeTraction Control System (TCS)
on page 4-6andStabiliTrak
®System on page 4-8for
more information.
Also seeCompetitive Driving Mode (STS-V) on
page 4-7for more information.
3-65

Lane Departure Warning Light
Your vehicle may have
the lane departure
warning system.
This light will come on green, briey, when the vehicle
is started to show that it is working. This light will
also come on green if the system detects a left or
right lane marking. This light will change to amber
and ash and three beeps will sound if you cross a
detected lane marking without using your turn signal.
For more information, see the Index in the Navigation
Manual.
Engine Coolant Temperature
Warning Light
The engine coolant
temperature warning
light will come on
when the engine
is very hot.
This light will also come on briey when the vehicle
is started.
If the light does not go out or comes on and stays
on while driving, there may be a problem with the
cooling system. Driving with engine coolant temperature
light on could cause your vehicle to overheat, see
Overheated Engine Protection Operating Mode on
page 5-31. SeeEngine Overheating on page 5-29
andDIC Warnings and Messages on page 3-80for
more information.
3-66

Engine Coolant Temperature Gage
This gage shows the
engine coolant
temperature.
It can be used to see when your engine has warmed up
and to make sure your cooling system is operating
properly. If the gage pointer moves into the shaded area,
the engine coolant is too hot and the engine coolant
temperature warning light will come on. SeeEngine
Overheating on page 5-29for more information.
Tire Pressure Light
This light comes on briey
when the engine is started.
This light will also come on when one or more of your
tires are signicantly underinated.
A tire pressure message in the Driver Information Center
(DIC), may accompany the light. SeeDIC Warnings and
Messages on page 3-80for 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 5-57for more information.
If a problem is detected with the Tire Pressure Monitor
System, this light will ash for approximately 60 seconds
and then stay on solid for the remainder of the ignition
cycle. SeeTire Pressure Monitor System on page 5-68
for more information.
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Malfunction Indicator Lamp
Check Engine Light
A computer system called OBD II (On-Board
Diagnostics-Second Generation) monitors operation of
the fuel, ignition, and emission control systems. It makes
sure 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 an OBD II
problem and service
is required.
Malfunctions often are indicated by the system before
any problem is apparent. This can 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 a while, 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,
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 can cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This could
also result in a failure to pass a required Emission
Inspection/Maintenance test. SeeAccessories
and Modifications on page 5-3.
This light comes on briey, as a check to show it is
working, as you start the engine. If the light does not
come on, have it repaired. This light also comes
on during a malfunction in one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and could damage the emission control system
on your vehicle. Diagnosis and service might
be required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service might be required.
3-68

If the Light Is Flashing
The following can prevent more serious damage to
your vehicle:
Reduce vehicle speed.
Avoid hard accelerations.
Avoid steep uphill grades.
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 the vehicle.
Turn the engine 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/retailer
for service as soon as possible.
If the Light Is On Steady
You might 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 5-7. The diagnostic
system can determine if the fuel cap has been left off or
improperly installed. A loose or missing fuel cap allows
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 vehicle’s electrical system might be wet. The
condition is usually 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. See
Gasoline Octane on page 5-5. Poor fuel quality causes
the engine not to run as efficiently as designed. You
might 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 might 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/retailer can check the vehicle. Your
dealer/retailer has the proper test equipment and
diagnostic tools to x any mechanical or electrical
problems that might have developed.
3-69

Emissions Inspection and
Maintenance Programs
Some state/provincial and local governments have or
might 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.
To perform a check engine light bulb check with the
keyless ignition, make sure the transmitter fob is in the
passenger compartment. SeeIgnition Positions on
page 2-28. Press the bottom of the Acc. button on the
instrument panel and hold the button down for ve
seconds. The instrument panel, including the check
engine light, will light up and the ignition will be on,
but the engine will not start — if you press the bottom
of the Acc. button only briey, less than ve seconds,
the accessory power mode will be turned on, but not
the ignition. After the bulb check, be sure to press and
release the Acc. button again to turn the ignition off
and avoid draining the vehicle’s battery.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 the battery or if the 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/retailer can prepare the vehicle for inspection.
Oil Pressure Light
Your vehicle may have
this feature.
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