Page 362 of 528
Black plate (12,1)Cadillac STS Owner Manual - 2011
Checking Things Under
the Hood
{WARNING:
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.
{WARNING:
Things that burn can get on hot engine parts and
start a fire. These include liquids like fuel, oil,
coolant, brake fluid, windshield washer and other
fluids, 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.
Hood Release
To open the hood:
1. Pull the hood releaselever with this symbol
on it. It is located
inside the vehicle on
the lower left side of
the instrument panel.
6-12
Page 365 of 528

Black plate (15,1)Cadillac STS Owner Manual - 2011
After you have removed the sight shields (if equipped):A. Underhood Fuse Block. See Underhood Fuse
Block on page 6‑116.
B. Remote Negative (-) Terminal. See Jump Starting
on page 6‑38.
C. Remote Positive (+) Terminal. See Jump Starting
on page 6‑38.
D. Battery. See Battery on page 6‑38.
E. Passenger Compartment Air Filter. See Passenger
Compartment Air Filter on page 4‑50.
F. Power Steering Fluid Reservoir. See Power
Steering Fluid on page 6‑33.
G. Engine Oil Fill Cap. See “When to Add Engine Oil”
under Engine Oil on page 6‑16.
H. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 6‑16. I. Brake Master Cylinder Reservoir. See
“Brake
Fluid” under Brakes on page 6‑35.
J. Engine Coolant Surge Tank and Pressure Cap. See Cooling System on page 6‑24.
K. Engine Air Cleaner/Filter. See Engine Air Cleaner/
Filter on page 6‑21.
L. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on
page 6‑34.
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.
6-15
Page 366 of 528

Black plate (16,1)Cadillac STS Owner Manual - 2011
Engine Oil
To ensure proper engine performance and long life,
careful attention must be paid to engine oil. Following
these simple, but important steps will help protect your
investment:
.Always use engine oil approved to the proper
specification and of the proper viscosity grade. See
“Selecting the Right Engine Oil.”
.Check the engine oil level regularly and maintain
the proper oil level. See“Checking Engine Oil”and
“When to Add Engine Oil.”
.Change the engine oil at the appropriate time. See
Engine Oil Life System on page 6‑20.
.Always dispose of engine oil properly. See “What
to Do With Used Oil.”
Checking Engine Oil
It is a good idea to check the engine oil level at each
fuel fill. In order to get an accurate reading, the vehicle
must be on level ground. The engine oil dipstick handle
is a yellow loop. See Engine Compartment Overview
on
page 6‑13for the location of the engine oil dipstick.
Obtaining an accurate oil level reading is essential: 1. If the engine has been running recently, turn off the engine and allow several minutes for the oil to
drain back into the oil pan. Checking your oil level
too soon after engine shut off will not provide an
accurate oil level reading.
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.
6-16
Page 367 of 528

Black plate (17,1)Cadillac STS Owner Manual - 2011
When to Add Engine Oil
If the oil is below the cross-hatched area at the tip of
the dipstick, add one liter/quart of the recommended oil
and then recheck the level. See“Selecting the Right
Engine Oil” for an explanation of what kind of oil to use.
For engine oil crankcase capacity, see Capacities and
Specifications on page 6‑128. Notice:
Do not add too much oil. Oil levels above or
below the acceptable operating range shown on the
dipstick are harmful to the engine. If you find that
you have an oil level above the operating range, i.e.
the engine has so much oil that the oil level gets
above the cross-hatched area that shows the proper
operating range, the engine could be damaged. You
should drain out the excess oil or limit your driving
of the vehicle and seek a service professional to
remove the excess amount of oil.
See Engine Compartment Overviewon page 6‑13for
the location of the engine oil fill cap.
Add enough oil to put the level somewhere in the proper
operating range. Push the dipstick all the way back in
when through.
6-17
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 377 of 528

Black plate (27,1)Cadillac STS Owner Manual - 2011
Checking Coolant
The vehicle must be on a level surface when checking
the coolant level.
The coolant surge tank and pressure cap are located on
the driver's side of the vehicle, toward the rear of the
engine compartment. SeeEngine Compartment
Overview
on page 6‑13for more information on
location. Check to see if coolant is visible in the coolant surge
tank. If the coolant inside the coolant surge tank is
boiling, do not do anything else until it cools down.
If coolant is visible but the coolant level is not at or
above the FULL COLD/FROID line, add a 50/50 mixture
of clean, drinkable water and DEX-COOL
®coolant at
the coolant surge tank, but be sure the cooling system
is cool before this is done.
When the engine is cold, the coolant level should be at
or above the FULL COLD/FROID line on the side of the
coolant surge tank. Follow the arrow from the top of the
tank down the side to the horizontal mark. If it is not,
there could be a leak in the cooling system.
If the coolant is low, add the coolant or take the vehicle
to a dealer for service
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Page 469 of 528

Black plate (119,1)Cadillac STS Owner Manual - 2011
Fuses MiniUsage
V/CHKInstrument Panel Module-Voltage
Check
WPR Wipe/Wash Module Assembly
WPR SW/VICS Rain Sensor, Wiper Switch
Relays Usage
A/C CMPRSR
CLTCH Air Conditioning Compressor Clutch
ACCY Accessory, Rain Sensor, Headlamp
Washer Relay Coil, Windshield
Wiper/Washer Module
BRK
VAC PUMP Brake Vacuum Pump
FAN S/P Cooling Fan Series/Parallel
FOG LAMP Fog Lamps FRT BLWR Front Blower Motor
FUEL COOL Fuel Cooling Pump
HI BEAM High Beam Headlamp
HI FAN SPD Cooling Fan High Speed HORN Horn
Relays Usage
LO FAN SPD Cooling Fan Low Speed
LOW BEAM
W/O HID/HID Low Beam Headlamp, High Intensity
Discharge (HID)
PRK LAMP Parking Lamps, Instrument Panel
Dimming, Rear License Plate Lamps
PWR/TRN Engine Controls
RUN CRNK Heated Washer Nozzle, Air Quality,
Antilock Brake System, Climate
Control Panel, TCM, ECM, Instrument
Panel Cluster
SPARE Spare
SPARE Spare
SPARE Spare
STRTR Starter
WPR HI Windshield Wiper High Speed
Circuit
Breakers Usage
HDLP WASH
Headlamp Washer Motor
(Circuit Breaker)
6-119
Page 478 of 528
Black plate (128,1)Cadillac STS Owner Manual - 2011
Capacities and Specifications
The following approximate capacities are given in metric and English conversions. SeeRecommended Fluids and
Lubricantson page 7‑9for more information.
Application Capacities
Metric English
Air Conditioning Refrigerant R134a For the air conditioning system refrigerant charge
amount, see the refrigerant label located under the hood. See your dealer for more information.
Brake Fluid Capacities 1.0 L1.1 qt
Cooling System 10.8 L11.4 qt
Engine Oil with Filter 5.7 L6.0 qt
Fuel Tank 66.2 L17.5 gal
Transmission Fluid 6-Speed Automatic (Pan Removal and Filter
Replacement) 6.3 L
6.7 qt
Wheel Nut Torque 140Y 100 lb ft
All capacities are approximate. When adding, be sure to fill to the approximate level as recommended in this manual.
Recheck the fluid level after filling.
Engine Specifications
Engine VIN CodeTransmission Spark Plug Gap
3.6L SIDI V6 Engine DAutomatic 1.11 mm (0.044 in)
6-128