2003 CADILLAC CTS light

2-87
CAUTION:
If the air bag readiness light stays on after you
start your vehicle, it means the air bag system
may not be working properly. The air bags in
your vehicle may not inflate in a crash, or they
could even inflate without a crash. To help avoid
injury to yourself or others, have your vehicle
serviced right away if the air bag readiness light
stays on after you start your vehicle.
The air bag readiness light should flash for a few
seconds when you turn the ignition key to ON. If the
light doesn't come on then, have it fixed so it will be
ready to warn you if there is a problem.
If there is a problem with the air bag system in your
vehicle, the Service Air Bag message will appear on the
DIC display. See ªService Air Bag Messageº later in
this section for more information.
Charging System Light
When you turn the key to
ON or START, this light
will come on briefly to
show that the generator and
battery charging systems are
working properly.
If this light stays on, your vehicle needs service. You
should take your vehicle to the dealer at once. To save
your battery until you get there, turn off all accessories.

2-88
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.
United States Canada
This light should come on briefly when you turn
the ignition key to ON. If it doesn't come on then,
have it fixed so it will be ready to warn you if there's
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 doesn't 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 floor.
It may take longer to stop. If the light is still on, have the
vehicle towed for service. See ªTowing Your Vehicleº in
the Index.
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've
pulled off the road and stopped carefully, have
the vehicle towed for service.

2-89
Anti-Lock Brake System Warning Light
With the anti-lock brake
system, the light(s) will
come on when your engine
is started and may stay
on for several seconds.
That's normal.
If the ABS warning light comes on and stays on, there
may be a problem with the antilock portion of the brake
system. If the red BRAKE light is not on, you still have
brakes, but you don't have antilock brakes. See ªBrake
System Warning Lightº earlier in this section.If the light stays on, turn the ignition to OFF. Or, if the
light comes on when you're driving, stop as soon as
possible and turn the ignition off. Then start the engine
again to reset the system. If the light still stays on, or
comes on again while you're driving, your vehicle needs
service. If the regular brake system warning light isn't
on, you still have brakes, but you don't have anti
-lock
brakes. If the regular brake system warning light is also
on, you don't have anti
-lock brakes and there's a
problem with your regular brakes. See ªBrake System
Warning Lightº earlier in this section.
The anti
-lock brake system warning light will come on
briefly when you turn the ignition key to ON. This is
normal. If the light doesn't come on then, have it fixed
so it will be ready to warn you if there is a problem.
If the ABS light stays on or comes on while you are
driving, pull off the road as soon as possible and stop
carefully. Try resetting the system by turning the
ignition off then back on. If the ABS light still stays on
or comes back on again while you are driving, your
vehicle needs service. Have the anti
-lock brake system
inspected as soon as possible.

2-90
Traction Control System Warning
(TRAC OFF) Light
If the TRAC OFF
warning light comes on
and stays on, there may
be a problem with the
traction control system.
The TRAC OFF light will come on briefly when you
turn the ignition to ON. If it doesn't come on then,
have it fixed so it will be ready to warn you if there is
a problem.The light will also come on if you turn the traction
control system OFF using the Traction On/Off button.
The traction control TC button is located in the
glove box.
If the TRAC OFF light stays on or comes on while you
are driving, pull off the road as soon as possible and stop
carefully. Try resetting the system by turning the
ignition off then back on. If the light still stays on or
comes back on again while you are driving, your vehicle
needs service. Have the traction control system
inspected as soon as possible. See ªTraction Control
Systemº in the Index.

2-91
Engine Coolant Temperature
Warning Light
This light tells you that your
engine has overheated.
This light will come on when you first start the vehicle
as a check to let you know that the light is working. It
will go out after a few seconds. If the light does not
come on, the bulb may be burned out. See your dealer
for assistance in changing the bulb.
If the light does not go out or if the light comes on and
stays on while you are driving, your vehicle may have a
problem with the cooling system. You should stop the
vehicle and turn off the engine as soon as possible to
avoid damage to the engine. A warning chime will
sound when this light is on, also.
See ªEngine Overheatingº in the Index.
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.

2-92
NOTICE:
If you keep driving your vehicle with this light
on, after a while, 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:
Modifications 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.
Modifications 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 doesn't come on, have it repaired.
This light will also come on during a malfunction in one
of two ways:

Light Flashing
-- A misfire condition has been
detected. A misfire increases vehicle emissions and
may damage the emission control system on your
vehicle. Dealer or qualified service center diagnosis
and service may be required.

Light On Steady
-- An emission control system
malfunction has been detected on your vehicle.
Dealer or qualified service center diagnosis and
service may be required.

2-93
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 flashing and remains on steady, see
ªIf the Light Is On Steadyº following.
If the light continues to flash, 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 ªIf the Light
Is On Steadyº following. If the light is still flashing,
follow the previous steps, and drive the vehicle to your
dealer or qualified service center for service.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. See ªFilling Your Tankº in the Index. 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.
Are you low on fuel?
As your engine starts to run out of fuel, your engine may
not run as efficiently as designed since small amounts of
air are sucked into the fuel line causing a misfire. The
system can detect this. Adding fuel should correct this
condition. Make sure to install the fuel cap properly. See
ªFilling Your Tankº in the Index. It will take a few
driving trips to turn the light off.

2-94
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
ªFuelº in the Index. 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, misfiring, 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,
have your dealer or qualified service center check the
vehicle. Your dealer has the proper test equipment and
diagnostic tools to fix 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 in order 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, see your dealer or qualified service center to
prepare the vehicle for inspection.