Page 370 of 528

Black plate (20,1)Cadillac STS Owner Manual - 2011
What to Do with Used Oil
Used engine oil contains certain elements that can be
unhealthy for your skin and could even cause cancer.
Do not let used oil stay on your skin for very long. Clean
your skin and nails with soap and water, or a good hand
cleaner. Wash or properly dispose of clothing or rags
containing used engine oil. See the manufacturer's
warnings about the use and disposal of oil products.
Used oil can be a threat to the environment. If you
change your own oil, be sure to drain all the oil from
the filter before disposal. Never dispose of oil by putting
it in the trash or pouring it on the ground, into sewers,
or into streams or bodies of water. Recycle it by taking it
to a place that collects used oil.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system that indicates when
to change the engine oil and filter. This is based on
engine revolutions and engine temperature, and not on
mileage. Based on driving conditions, the mileage at
which an oil change is indicated can vary considerably.
For the oil life system to work properly, the system must
be reset every time the oil is changed.When the system has calculated that oil life has been
diminished, it indicates that an oil change is necessary.
A CHANGE ENGINE OIL SOON message in the DIC
comes on. See
DIC Warnings and Messages
on
page 4‑76. Change the oil as soon as possible within
the next 600 miles (1 000 km). It is possible that,
if driving under the best conditions, the oil life system
might indicate that an oil change is not necessary for up
to a year. The engine oil and filter must be changed at
least once a year and, at this time, the system must be
reset. Your dealer has trained service people who will
perform this work and reset the system. It is also
important to check the oil regularly over the course of
an oil drain interval and keep it at the proper level.
If the system is ever reset accidentally, the oil must be
changed at 3,000 miles (5 000 km) since the last oil
change. Remember to reset the oil life system
whenever the oil is changed.
6-20
Page 373 of 528

Black plate (23,1)Cadillac STS Owner Manual - 2011
Automatic Transmission Fluid
How to Check Automatic Transmission
Fluid
It is not necessary to check the transmission fluid level.
A transmission fluid leak is the only reason for fluid
loss. If a leak occurs, take the vehicle to the dealer
service department and have it repaired as soon as
possible.
The vehicle is not equipped with a transmission fluid
level dipstick. There is a special procedure for checking
and changing the transmission fluid. Because this
procedure is difficult, it should be done at the dealer
service department. Contact the dealer for additionalinformation or the procedure can be found in the service
manual. To purchase a service manual, see
Service
Publications Ordering Information on page 8‑17.
Notice: Use of the incorrect automatic transmission
fluid may damage the vehicle, and the damages may
not be covered by the vehicle's warranty. Always
use the automatic transmission fluid listed in
Recommended Fluids and Lubricants on page 7‑9.
Change the fluid and filter at the intervals listed in
Scheduled Maintenance
on page 7‑3, and be sure
to use the fluid listed in Recommended Fluids and
Lubricants on page 7‑9.
6-23
Page 480 of 528

Black plate (2,1)Cadillac STS Owner Manual - 2011
Maintenance Schedule
Introduction
Notice:Maintenance intervals, checks, inspections,
recommended fluids, and lubricants are necessary
to keep this vehicle in good working condition.
Damage caused by failure to follow scheduled
maintenance might not be covered by the vehicle
warranty.
As the vehicle owner, you are responsible for the
scheduled maintenance in this section. We recommend
having your dealer perform these services. Proper
vehicle maintenance helps to keep the vehicle in good
working condition, improves fuel economy, and reduces
vehicle emissions for better air quality.
Because of all the different ways people use vehicles,
maintenance needs vary. The vehicle might need
more frequent checks and services. Please read the
information under Scheduled Maintenance. To keep
the vehicle in good condition, see your dealer. The maintenance schedule is for vehicles that:
.carry passengers and cargo within recommended
limits on the Tire and Loading Information label.
See
Loading the Vehicle on page 5‑23.
.are driven on reasonable road surfaces within legal
driving limits.
.use the recommended fuel. See Gasoline Octaneon page 6‑7.
{WARNING:
Performing maintenance work on a vehicle can be
dangerous. In trying to do some jobs, you can be
seriously injured. Do your own maintenance work
only if you have the required know-how and the
proper tools and equipment for the job. If you
have any doubt, see your dealer to have a
qualified technician do the work. See Doing Your
Own Service Work on page 6‑5.
7-2
Page 484 of 528

Black plate (6,1)Cadillac STS Owner Manual - 2011
Once Every Two Years
.Vehicles using DOT 4 brake fluid only: Brake fluid
replacement.
First Engine Oil Change After Every
40 000 km/25,000 Miles
.Passenger compartment air filter replacement
(or every 24 months, whichever occurs first).
More frequent replacement may be needed if
you drive in areas with heavy traffic, areas with
poor air quality, or areas with high dust levels.
Replacement may also be needed if you notice
reduced air flow, windows fogging up, or odors.
Your dealer can help you determine when it is the
right time to replace the filter.
First Engine Oil Change After Every
80 000 km/50,000 Miles
.Engine air cleaner filter replacement. SeeEngine
Air Cleaner/Filter on page 6‑21.
.Automatic transmission fluid and filter change
(severe service) for vehicles mainly driven in heavy
city traffic in hot weather, in hilly or mountainous
terrain, when frequently towing a trailer, or used for
taxi, police, or delivery service. See Automatic
Transmission Fluid on page 6‑23.
.All‐wheel drive only: Transfer case fluid change
(severe service) for vehicles mainly driven when
frequently towing a trailer, or used for taxi, police,
or delivery service. Check vent hose at transfer
case for kinks and proper installation. Check to be
sure vent hose is unobstructed, clear, and free of
debris.
.Evaporative control system inspection. Check all
fuel and vapor lines and hoses for proper hook‐up,
routing, and condition. Check that the purge valve,
if the vehicle has one, works properly. Replace as
needed. An Emission Control Service. The U.S.
Environmental Protection Agency or the California
Air Resources Board has determined that the
failure to perform this maintenance item will not
nullify the emission warranty or limit recall liability
prior to the completion of the vehicle's useful life.
We, however, urge that all recommended
maintenance services be performed at the
indicated intervals and the maintenance be
recorded.
7-6