2009 CADILLAC STS check engine

Filling a Portable Fuel Container
{CAUTION:
Never ll a portable fuel container while it is in
the vehicle. Static electricity discharge from the
container can ignite the fuel vapor. You can be
badly burned and the vehicle damaged if this
occurs. To help avoid injury to you and others:
Dispense fuel only into approved containers.
Do not ll a container while it is inside a
vehicle, in a vehicle’s trunk, pickup bed,
or on any surface other than the ground.
Bring the ll nozzle in contact with the inside
of the ll opening before operating the nozzle.
Contact should be maintained until the lling
is complete.
Do not smoke while pumping fuel.
Do not use a cellular phone while
pumping fuel.
Checking Things Under
the Hood
{CAUTION:
An electric fan under the hood can start up and
injure you even when the engine is not running.
Keep hands, clothing, and tools away from any
underhood electric fan.
{CAUTION:
Things that burn can get on hot engine parts and
start a re. These include liquids like fuel, oil,
coolant, brake uid, windshield washer and other
uids, and plastic or rubber. You or others could
be burned. Be careful not to drop or spill things
that will burn onto a hot engine.
5-10

After you have removed the sight shields (if equipped) on the 3.6L V6 engine, here is what you will see:
A. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-124.
B. Remote Negative (-) Terminal. SeeJump Starting on
page 5-42.
C. Remote Positive (+) Terminal. SeeJump Starting on
page 5-42.
D. Battery. SeeBattery on page 5-42.
E. Passenger Compartment Air Filter. SeePassenger
Compartment Air Filter on page 3-54.
F. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-37.
G. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-18.H. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 5-18.
I. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-39.
J. Engine Coolant Surge Tank and Pressure Cap.
SeeCoolant Surge Tank Pressure Cap on page 5-34
andCooling System on page 5-26.
K. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-23.
L. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-38.
5-13

After you have removed the sight shields (if equipped) on the 4.6L V8 engine, here is what you will see:
A. Remote Negative (-) Terminal. SeeJump Starting on
page 5-42.
B. Remote Positive (+) Terminal. SeeJump Starting on
page 5-42.
C. Battery. SeeBattery on page 5-42.
D. Passenger Compartment Air Filter. SeePassenger
Compartment Air Filter on page 3-54.
E. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-37.
F. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-18.
G. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 5-18.H. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-39.
I. Engine Coolant Surge Tank and Pressure Cap.
SeeCoolant Surge Tank Pressure Cap on page 5-34
andCooling System on page 5-26.
J. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-23.
K. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-124.
L. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-38.
5-15

After you have removed the sight shields (if equipped) on the 4.4L V8 STS-V engine, here is what you will see:
A. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-124.
B. Remote Positive (+) Terminal. SeeJump Starting on
page 5-42.
C. Remote Negative (-) Terminal. SeeJump Starting on
page 5-42.
D. Battery. SeeBattery on page 5-42.
E. Passenger Compartment Air Filter. SeePassenger
Compartment Air Filter on page 3-54.
F. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-38.
G. Intercooler System Pressure Cap. SeeEngine
Coolant on page 5-27.
H. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-37.I. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-18.
J. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 5-18.
K. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-39.
L. Engine Coolant Surge Tank and Pressure Cap.
SeeCoolant Surge Tank Pressure Cap on page 5-34
andCooling System on page 5-26.
M. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-23.
If your vehicle is equipped with front compartment
underhood sight shields, before closing the hood be
sure to reinstall the sight shields. To reinstall the shields,
locate the tabs on the left and right sides and insert them
into the openings in the tower to tower brace. Then insert
the fasteners into the top of the shield and push the
fasteners back into place.
5-17

Engine Oil
Checking Engine Oil
It is a good idea to check the engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop.
SeeEngine Compartment Overview on page 5-12
for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes
to drain back into the oil pan. If you do not do this,
the oil dipstick might not show the actual level.
2. Pull out the dipstick and clean it with a paper towel
or cloth, then push it back in all the way. Remove it
again, keeping the tip down, and check the level.
When to Add Engine Oil
V6 Engine
V8 Engine
5-18

Engine Oil Additives / Engine Oil
Flushes
Do not add anything to the oil. The recommended oils
with the starburst symbol that meet GM standards are all
you need for good performance and engine protection.
Engine oil system ushes are not recommended
and could cause engine damage not covered by
the vehicle warranty.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system that lets you
know when to change the engine oil and lter. This is
based on engine revolutions and engine temperature,
and not on mileage. Based on driving conditions, the
mileage at which an oil change will be indicated can vary
considerably. For the oil life system to work properly, you
must reset the system every time the oil is changed.Notice:If your vehicle is an STS-V model, the
engine uses a special oil lter. The use of any
other engine oil lter could lead to lter failure and
result in severe engine damage. Damage caused
by use of the wrong engine oil lter would not
be covered by your new vehicle warranty.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is necessary.
A CHANGE ENGINE OIL SOON message in the DIC
will come on. SeeDIC Warnings and Messages on
page 3-79. Change the oil as soon as possible within the
next 600 miles (1 000 km). It is possible that, if you are
driving under the best conditions, the oil life system might
not indicate that an oil change is necessary for over a
year. However, the engine oil and lter must be changed
at least once a year and at this time the system must be
reset. Your dealer/retailer has trained service people who
will perform this work using genuine parts and reset the
system. It is also important to check the oil regularly and
keep it at the proper level.
If the system is ever reset accidentally, you must
change the oil at 3,000 miles (5 000 km) since the
last oil change. Remember to reset the oil life system
whenever the oil is changed.
5-21

How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/lter remove the lter from the
vehicle and lightly shake the lter to release loose dust
and dirt. If the lter remains caked with dirt, a new lter
is required.
To inspect or replace the lter in the 3.6L V6 or
4.6L V8 engines, do the following:
1. Remove the two screws located on the top of
the cover.
2. Disconnect the coolant recovery hose so that
it is not going across the top of the engine air
cleaner/lter.
3. Loosen the clamp and remove the duct from the
passenger’s side of the engine air cleaner/lter.4. The two sides of the airbox are hinged at the
bottom. Open the airbox by pushing the top of
the airbox cover toward the engine.
5. Remove the air lter by lifting it straight up through
the opening in the airbox.
6. Inspect or replace the engine air cleaner/lter.
SeeMaintenance Replacement Parts on page 6-15
for the correct part number for the lter.
7. Reinstall the cover by reversing Steps 1 through 4.
If your vehicle has the 4.4L V8 STS-V engine, there
is a special procedure for checking and changing the
air cleaner/lter. 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 7-15.
5-24

{CAUTION:
Operating the engine with the air cleaner/lter
off can cause you or others to be burned. The air
cleaner not only cleans the air; it helps to stop
ames if the engine backres. If it is not there and
the engine backres, you could be burned. Do not
drive with it off, and be careful working on the
engine with the air cleaner/lter off.
Notice:If the air cleaner/lter is off, a backre can
cause a damaging engine re. And, dirt can easily get
into the engine, which will damage it. Always have
the air cleaner/lter in place when you are driving.
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 dealer/retailer
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 dealer/retailer
service department. Contact your dealer/retailer for
additional information or the procedure can be found
in the service manual. To purchase a service manual,
seeService Publications Ordering Information on
page 7-15.
Notice:Use of the incorrect automatic transmission
uid may damage the vehicle, and the damages
may not be covered by the vehicle’s warranty.
Always use the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-13.
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 6-13.
5-25