2006 CADILLAC STS check engine light

If equipped, 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 System on
page 2-21.
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 3-37for more information.
Lights On Reminder
This light comes on
whenever the parking
lamps are on.
SeeHeadlamps on Reminder on page 3-35for more
information.
3-71

If this message appears immediately after starting the
engine, it is possible that the generator can still recharge
the battery. The battery should recharge while driving
but may take a few hours to do so. Consider using
an auxiliary charger to boost the battery after returning
home or to a nal destination. Make sure you follow
the manufacturer’s instructions.
If this message appears while driving or after starting
your vehicle and stays on, have it checked immediately
to determine the cause of this problem.
To help the generator recharge the battery quickly, you
can reduce the load on the electrical system by
turning off the accessories.
The normal battery voltage range is 11.5 to 15.5 volts.
You can monitor battery voltage on the DIC by pressing
the information button until you nd BATTERY VOLTS.
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 5-18andScheduled 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 5-22.
CHECK BRAKE FLUID
This message will display if the ignition is on to inform
the driver that the brake uid level is low. Have the
brake system serviced by your GM dealer as soon as
possible. SeeBrake System Warning Light on page 3-64
for more information.
CHECK COOLANT LEVEL
This message will display when there is a low level of
engine coolant. Have the cooling system serviced
by your GM dealer as soon as possible. SeeEngine
Coolant on page 5-26for more information.
CHECK GAS CAP
When this message displays, the gas cap has not been
fully tightened. You should recheck the gas cap to
ensure that it is on and tightened properly.
CHECK OIL LEVEL
This message will display when the oil level is low. See
Engine Oil on page 5-18for more information on
checking your engine oil.
3-81

Avoid needless heavy braking. Some people drive
in spurts — heavy acceleration followed by heavy
braking — rather than keeping pace with traffic. This is
a mistake. Your brakes may not have time to cool
between hard stops. Your brakes will wear out much
faster if you do a lot of heavy braking. If you keep pace
with the traffic and allow realistic following distances,
you will eliminate a lot of unnecessary braking.
That means better braking and longer brake life.
If your engine ever stops while you are driving, brake
normally but do not pump your brakes. If you do,
the pedal may get harder to push down. If your engine
stops, you will still have some power brake assist.
But you will use it when you brake. Once the power
assist is used up, it may take longer to stop and
the brake pedal will be harder to push.
Adding non-GM accessories can affect your vehicle’s
performance. SeeAccessories and Modications
on page 5-3.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 3-65.
4-7

While driving on a surface with reduced traction, try your
best to avoid sudden steering, acceleration, or braking,
including reducing vehicle speed by shifting to a lower
gear. Any sudden changes could cause the tires to
slide. You may not realize the surface is slippery until
your vehicle is skidding. Learn to recognize warning
clues — such as enough water, ice, or packed snow on
the road to make a mirrored surface — and slow down
when you have any doubt.
Remember: Any Anti-Lock Brake System (ABS) helps
avoid only the braking skid.
Competitive Driving
See your warranty book before using your vehicle for
competitive driving.
Notice:If you use your vehicle for racing or other
competitive driving, the engine may use more
oil than it would with normal use. Low oil levels can
damage the engine. Be sure to check the oil level
often during racing or other competitive driving
and keep the level at or near the upper mark that
shows the proper operating range on the engine oil
dipstick. For information on how to add oil, see
Engine Oil on page 5-18.
Driving at Night
Night driving is more dangerous than day driving.
One reason is that some drivers are likely to be
impaired — by alcohol or drugs, with night vision
problems, or by fatigue.
Here are some tips on night driving.
Drive defensively.
Do not drink and drive.
Adjust the inside rearview mirror to reduce the glare
from headlamps behind you.
Since you cannot see as well, you may need to
slow down and keep more space between you
and other vehicles.
Slow down, especially on higher speed roads.
Your vehicle’s headlamps can light up only so much
road ahead.
In remote areas, watch for animals.
If you are tired, pull off the road in a safe place
and rest.
4-18

Once you are moving on the freeway, make certain
you allow a reasonable following distance.
Expect to move slightly slower at night.
When you want to leave the freeway, move to the
proper lane well in advance. If you miss your exit,
do not, under any circumstances, stop and back up.
Drive on to the next exit.
The exit ramp can be curved, sometimes quite sharply.
The exit speed is usually posted. Reduce your speed
according to your speedometer, not to your sense
of motion. After driving for any distance at higher
speeds, you may tend to think you are going slower
than you actually are.
Before Leaving on a Long Trip
Make sure you are ready. Try to be well rested. If you
must start when you are not fresh — such as after
a day’s work — do not plan to make too many miles
that rst part of the journey. Wear comfortable clothing
and shoes you can easily drive in.Is your vehicle ready for a long trip? If you keep it
serviced and maintained, it is ready to go. If it needs
service, have it done before starting out. Of course, you
will nd experienced and able service experts in GM
dealerships all across North America. They will be ready
and willing to help if you need it.
Here are some things you can check before a trip:
Windshield Washer Fluid:Is the reservoir full?
Are all windows clean inside and outside?
Wiper Blades:Are they in good shape?
Fuel, Engine Oil, Other Fluids:Have you checked
all levels?
Lamps:Are they all working? Are the lenses clean?
Tires:They are vitally important to a safe,
trouble-free trip. Is the tread good enough for
long-distance driving? Are the tires all inated to
the recommended pressure?
Weather Forecasts:What is the weather outlook
along your route? Should you delay your trip a
short time to avoid a major storm system?
Maps:Do you have up-to-date maps?
4-24

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of
Your Vehicle..............................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-18
Engine Oil Life System..................................5-22
Engine Air Cleaner/Filter................................5-24
Automatic Transmission Fluid.........................5-26
Engine Coolant.............................................5-26
Coolant Surge Tank Pressure Cap..................5-30
Engine Overheating.......................................5-30
Overheated Engine Protection
Operating Mode........................................5-31Cooling System............................................5-32
Power Steering Fluid.....................................5-39
Windshield Washer Fluid................................5-40
Brakes........................................................5-41
Battery........................................................5-44
Jump Starting...............................................5-45
All-Wheel Drive..............................................5-50
Rear Axle.......................................................5-51
Front Axle......................................................5-52
Bulb Replacement..........................................5-53
High Intensity Discharge (HID) Lighting............5-53
Halogen Bulbs..............................................5-53
Back-Up Lamps............................................5-54
Replacement Bulbs.......................................5-54
Windshield Replacement.................................5-55
Windshield Wiper Blade Replacement..............5-55
Tires..............................................................5-56
Tire Sidewall Labeling...................................5-58
Tire Terminology and Denitions.....................5-60
Run-Flat Tires (STS-V)..................................5-63
Ination - Tire Pressure.................................5-64
Tire Pressure Monitor System.........................5-66
Tire Inspection and Rotation...........................5-70
When It Is Time for New Tires.......................5-71
Section 5 Service and Appearance Care
5-1

Adding Equipment to the
Outside of Your Vehicle
Things you might add to the outside of your vehicle can
affect the airow around it. This may cause wind noise
and affect windshield washer performance. Check with
your dealer before adding equipment to the outside of
your vehicle.
Fuel
The 8th digit of your vehicle identication number (VIN)
shows the code letter or number that identies your
engine. You will nd the VIN at the top left of the
instrument panel. SeeVehicle Identication Number
(VIN) on page 5-103.
Gasoline Octane
If your vehicle has the 3.6L V6 engine (VIN Code 7), use
regular unleaded gasoline with a posted octane rating of
87 or higher. For best performance or trailer towing, you
may choose to use middle grade 89 octane unleaded
gasoline. If the octane rating is less than 87, you may
notice an audible knocking noise when you drive,
commonly referred to as spark knock. If this occurs, use a
gasoline rated at 87 octane or higher as soon as possible.
If you are using gasoline rated at 87 octane or higher and
you hear heavy knocking, your engine needs service.
If your vehicle has the 4.6L V8 engine (VIN Code A), use
premium unleaded gasoline with a posted octane rating
of 91 or higher. You may also use regular unleaded
gasoline rated at 87 octane or higher, but your vehicle’s
acceleration may be slightly reduced, and you may notice
a slight audible knocking noise, commonly referred to as
spark knock. If the octane is less than 87, you may notice
a heavy knocking noise when you drive. If this occurs,
use a gasoline rated at 87 octane or higher as soon as
possible. Otherwise, you might damage your engine. If
you are using gasoline rated at 87 octane or higher and
you hear heavy knocking, your engine needs service.
5-5

Automatic Transmission Fluid
How to Check Automatic
Transmission Fluid
It is not necessary to check the transmission uid level.
A transmission uid leak is the only reason for uid
loss. If a leak occurs, take the vehicle to the dealership
service department and have it repaired as soon as
possible.
There is a special procedure for checking and changing
the transmission uid. Because this procedure is
difficult, you should have this done at the dealership
service department. Contact your dealer for additional
information or the procedure can be found in the service
manual. To purchase a service manual, seeService
Publications Ordering Information on page 7-14.
Notice:Use of the incorrect automatic transmission
uid may damage your vehicle, and the damages
may not be covered by your warranty. Always
use the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-12.
Change the uid and lter at the intervals listed in
Additional Required Services on page 6-6, and be sure
to use the uid listed inRecommended Fluids and
Lubricants on page 6-12.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem with
engine overheating, seeEngine Overheating on
page 5-30.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at the rst maintenance
service after each 30,000 miles (50 000 km) or
24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
5-26