check engine light CADILLAC DTS PROFESSIONAL 2006 1.G Owners Manual

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 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 5-93. 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.
To program the new key do the following:
1. Verify that the new key has a
1stamped on it.
2. Insert the original, already programmed, key in the
ignition and start the engine. If the engine will not
start, see your dealer for service.
3. After the engine has started, turn the key to OFF,
and remove the key.
4. Insert the new key to be programmed and turn it to
the RUN position within ve seconds of removing
the original key.
5. The security light will turn off once the key has
been programmed.
6. Repeat Steps 1 through 5 if additional keys are to
be programmed.
If you are driving and the security light comes on and
stays on, you may be able to restart your engine.
Your PASS-Key
®III+ system, however, may not be
working properly and must be serviced by your dealer.
If you lose or damage your PASS-Key
®III+ key,
see your dealer or a locksmith who can service
PASS-Key
®III+ to have a new key made.
2-22

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 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 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. 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 are a big help.
Your vehicle also has a Driver Information Center (DIC)
that works along with the warning lights and gages.
SeeDriver Information Center (DIC) on page 3-71for
more information.
3-55

Speedometer and Odometer
Your speedometer lets you see your speed in both
miles per hour (mph) and kilometers per hour (km/h).
See “MPH (km)” underDIC Controls and Displays
on page 3-72for more information.
The odometer mileage can be checked without
the vehicle running. Your vehicle’s odometer works
together with the driver information center. You can set
a Trip A and a Trip B odometer. See “Trip Information”
underDIC Controls and Displays on page 3-72for
more information.
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
This gage indicates
the engine speed in
revolutions per
minute (rpm).
Safety Belt Reminder Light
When the key is turned to RUN or START, a chime will
sound for several seconds to remind you and your
passengers to buckle your safety belts. The driver safety
belt light will also come on 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 come on.
3-57

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.
3-66

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 hasbeen 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. See
Gasoline 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.
3-67

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, your GM 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.
3-68

This light tells you if there
could be a problem with
your engine oil pressure.
This light will come on briey when 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 2-19.
Fog Lamp Light
The fog lamps 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 3-35for more information.
Rear Fog Lamp Light
This light will come on
when the rear fog lamps
are in use. For more
information seeFog Lamps
on page 3-35.
Canada Only
3-69

CHANGE ENGINE OIL SOON
When this message displays, it means that service is
required for your vehicle. See your GM dealer. See
Engine Oil on page 5-13andScheduled Maintenance
on page 6-4for more information.
When you reset the CHANGE ENGINE OIL SOON
message by clearing it from the display, you still must
reset the engine oil life system separately. For more
information on resetting the engine oil life system, see
Engine Oil Life System on page 5-16.
CHECK TIRE PRESSURE
This symbol appears with
this message.
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 5-49,Loading
Your Vehicle on page 4-31, andInation - Tire Pressure
on page 5-56. The DIC display also shows the tire
pressure values for the front and rear tires by pressing
the vehicle information button. SeeDIC Controls
and Displays on page 3-72. If the tire pressure is low,
the low tire pressure warning light will come on. SeeLow
Tire Pressure Warning Light on page 3-63.
3-77

ENGINE OIL LOW ADD OIL
This message will display when the oil level is low. See
Engine Oil on page 5-13for more information on
checking your engine oil.
ENGINE OVERHEATED IDLE ENGINE
Notice:If you drive your vehicle while the engine is
overheating, severe engine damage may occur. If
an overheat warning appears on the instrument
panel cluster and/or DIC, stop the vehicle as soon
as possible. Do not increase the engine speed above
normal idling speed. SeeEngine Overheating on
page 5-25for more information.
This message will display when the engine coolant
temperature is too hot. Stop and allow the vehicle to idle
until it cools down. SeeEngine Coolant Temperature
Warning Light on page 3-65.
SeeOverheated Engine Protection Operating Mode on
page 5-27for information on driving to a safe place
in an emergency.
ENGINE OVERHEATED STOP ENGINE
Notice:If you drive your vehicle while the engine
is overheating, severe engine damage may occur.
If an overheat warning appears on the instrument
panel cluster and/or DIC, stop the vehicle as soon as
possible. Do not increase the engine speed above
normal idling speed. SeeEngine Overheating
on page 5-25for more information.
This message will display when the engine has
overheated. Immediately look for a safe place to pull
your vehicle over and turn the engine off right away to
avoid severe engine damage. SeeEngine Overheating
on page 5-25andOverheated Engine Protection
Operating Mode on page 5-27. A chime will also sound
when this message is displayed.
ENGINE POWER REDUCED
This message will display when the engine power is
being reduced to protect the engine from damage. There
could be several malfunctions that might cause this
message. Reduced engine power can affect the vehicle’s
ability to accelerate. If this message is on, but there is no
reduction in performance, proceed to your destination.
The performance may be reduced the next time the
vehicle is driven. The vehicle may be driven at a reduced
speed while this message is on, but acceleration and
speed may be reduced. Anytime this message stays on,
the vehicle should be taken to your GM dealer for service
as soon as possible.
3-79

Anti-Lock Brake System (ABS)
Your vehicle has the Anti-Lock Brake System (ABS), an
advanced electronic braking system that will help prevent
a braking skid.
When you start your engine and 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 a little.
This is normal.
If there is a problem with
ABS, this warning light will
stay on. SeeAnti-Lock
Brake System Warning
Light on page 3-63.
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