
Black plate (22,1)Cadillac STS Owner Manual - 2011
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter at the scheduled
maintenance intervals and replace it at the first oil
change after each 80 000 km (50,000 mile) interval. See
Scheduled Maintenance
on page 7‑3for more
information. If you are driving in dusty/dirty conditions,
inspect the filter at each engine oil change.
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/filter remove the filter from the
vehicle and lightly shake the filter to release loose dust
and dirt. If the filter remains caked with dirt, a new filter
is required.
To inspect or replace the filter:
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/
filter.
3. Loosen the clamp and remove the duct from the passenger's side of the engine air cleaner/filter. 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 filter by lifting it straight up through the opening in the airbox.
6. Inspect or replace the engine air cleaner/filter. See Maintenance Replacement Parts
on page 7‑11for
the correct part number for the filter.
7. Reinstall the cover by reversing Steps 1 through 4.
{WARNING:
Operating the engine with the air cleaner/filter off
can cause you or others to be burned. The air
cleaner not only cleans the air; it helps to stop
flames if the engine backfires. Use caution when
working on the engine and do not drive with the
air cleaner/filter off.
Notice: If the air cleaner/filter is off, dirt can easily
get into the engine, which could damage it. Always
have the air cleaner/filter in place when you are
driving.
6-22

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

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

Black plate (4,1)Cadillac STS Owner Manual - 2011
Every Engine Oil Change
.Change engine oil and filter. Reset oil life system.
SeeEngine Oilon page 6‑16andEngine Oil Life
Systemon page 6‑20. An Emission Control
Service.
.Engine coolant level check. See Engine Coolanton page 6‑25.
.Engine cooling system inspection. Visual
inspection of hoses, pipes, fittings, and clamps and
replacement, if needed.
.Windshield washer fluid level check. See
Windshield Washer Fluid on page 6‑34.
.Windshield wiper blade inspection for wear,
cracking, or contamination and windshield and
wiper blade cleaning, if contaminated. See
Windshield and Wiper Blades
on page 6‑111. Worn
or damaged wiper blade replacement. See
Windshield Wiper Blade Replacement
on
page 6‑49.
.Tire inflation pressures check. See Inflation - Tire
Pressure on page 6‑58.
.Tire wear inspection. See Tire Inspection and
Rotation on page 6‑65.
.If tire rotation is recommended for the vehicle,
rotate tires if necessary. See Tire Inspection and
Rotation on page 6‑65.
.Fluids visual leak check (or every 12 months,
whichever occurs first). A leak in any system must
be repaired and the fluid level checked.
.Engine air cleaner filter inspection. See Engine Air
Cleaner/Filter on page 6‑21.
.Brake system inspection (or every 12 months,
whichever occurs first).
.Steering and suspension inspection. Visual
inspection for damaged, loose, or missing parts
or signs of wear.
.Body hinges and latches, key lock cylinders,
rear compartment hinges, console door hinges,
and glove box door hinges lubrication. See
Recommended Fluids and Lubricants
on
page 7‑9. More frequent lubrication may be
required when the vehicle is exposed to a
corrosive environment. Applying silicone grease
on weatherstrips with a clean cloth makes them
last longer, seal better, and not stick or squeak.
.Restraint system component check. See Checking
the Restraint Systems on page 2‑72.
.Fuel system inspection for damage or leaks.
.Exhaust system and nearby heat shields
inspection for loose or damaged components.
7-4

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

Black plate (11,1)Cadillac STS Owner Manual - 2011
Maintenance Replacement Parts
Replacement parts identified below by name, part number, or specification can be obtained from your dealer.Part GM Part Number ACDelco Part Number
Engine Air Cleaner/Filter Element 25798271A2944C
Engine Oil Filter 25177917PF2129
Passenger Compartment Air Filter 88957450CF13C
Spark Plugs 9222044741-990
Wiper Blades
Driver Side –56.5 cm (22 in) 88958361—
Passenger Side –53.0 cm (21 in) 88958359—
7-11

Black plate (1,1)Cadillac STS Owner Manual - 2011
A
Accessories and Modifications . . . . . . . . . . . . . . . . . . . . . . .6-4
Accessory Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27
Accessory Power Outlets . . . . . . . . . . . . . . . . . . . . . . . . . . 4-42
Adaptive Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
Add-On Electrical Equipment . . . . . . . . . . . . . . . . . . . . . 6-114
Additives, Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-7
AdjustmentsHeadlamp Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
Air Cleaner/Filter, Engine . . . . . . . . . . . . . . . . . . . . . . . . . . 6-21
Air Filter, Passenger Compartment . . . . . . . . . . . . . . . . 4-50
Airbag Adding Equipment to Your Airbag-EquippedVehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-71
Airbag System How Does an Airbag Restrain? . . . . . . . . . . . . . . . . . . . 2-63
Passenger Sensing System . . . . . . . . . . . . . . . . . . . . . . 2-66
Servicing Your Airbag-Equipped Vehicle . . . . . . . . . . 2-70
What Makes an Airbag Inflate? . . . . . . . . . . . . . . . . . . . 2-63
What Will You See After an Airbag Inflates? . . . . . . 2-64
When Should an Airbag Inflate? . . . . . . . . . . . . . . . . . . 2-62
Where Are the Airbags? . . . . . . . . . . . . . . . . . . . . . . . . . . 2-59
Airbags Passenger Status Indicator . . . . . . . . . . . . . . . . . . . . . . . 4-55
Readiness Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-54
System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-57
All-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-43 All-Wheel-Drive (AWD) System . . . . . . . . . . . . . . . . . . . . 5-11
Antenna
Backglass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-126
Antenna, XM™ Satellite Radio Antenna
System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-126
Antilock Brake System (ABS) . . . . . . . . . . . . . . . . . . . . . . . .5-5 Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-59
Appearance Care Aluminum or Chrome-Plated Wheels . . . . . . . . . . . . 6-112
Care of Safety Belts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-109
Chemical Paint Spotting . . . . . . . . . . . . . . . . . . . . . . . . . 6-113
Cleaning Exterior Lamps/Lenses . . . . . . . . . . . . . . . . 6-110
Fabric/Carpet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-107
Finish Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-110
Finish Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-113
Instrument Panel, Vinyl, and Other PlasticSurfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-108
Interior Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-106
Leather . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-108
Sheet Metal Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-113
Speaker Covers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-109
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-113
Underbody Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . 6-113
Washing Your Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . .6-109
Weatherstrips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-109
Windshield and Wiper Blades . . . . . . . . . . . . . . . . . . . . 6-111
Wood Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-109
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Black plate (5,1)Cadillac STS Owner Manual - 2011
E
EDR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19
Electrical Equipment, Add-On . . . . . . . . . . . . . . . . . . . . 6-114
Electrical SystemFuses and Circuit Breakers . . . . . . . . . . . . . . . . . . . . . . 6-115
Headlamp Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-115
Power Windows and Other Power Options . . . . . . 6-115
Rear Underseat Fuse Block . . . . . . . . . . . . . . . . . . . . .6-120
Underhood Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . 6-116
Windshield Wiper Fuses . . . . . . . . . . . . . . . . . . . . . . . . . 6-115
Engine
Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-21
Check and Service Engine Soon Light . . . . . . . . . . . . 4-62
Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13
Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-25
Coolant Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29
Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . 4-61
Coolant Temperature Warning Light . . . . . . . . . . . . . . 4-61
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-24
Drive Belt Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36
Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-16
Overheated Protection Operating Mode . . . . . . . . . . 6-32
Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-30
Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27
Engine Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-20 Enhanced StabiliTrak
®. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-7
Entry Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-36
Event Data Recorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19
Extender, Safety Belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-34
Exterior Lighting Battery Saver . . . . . . . . . . . . . . . . . . . . 4-35
F
Filter Engine Air Cleaner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-21
Finish Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-113
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-9
Flashers, Hazard Warning . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-74
Flat Tire, Changing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-94
Flat Tire, Storing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-103
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-56
Fluid Automatic Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . 6-23
Power Steering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-33
Windshield Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-34
Fog Lamps Bulb Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-33
Forward Collision Alert (FCA) System . . . . . . . . . . . . . . .4-6
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-45
Front Fog Lamps
Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-67
i - 5