Page 353 of 528
Black plate (3,1)Cadillac STS Owner Manual - 2011
Section 6 Service and Appearance Care
Vehicle Identification. . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-114
Vehicle Identification Number (VIN) . . . . . . . . . . . 6-114
Service Parts Identification Label . . . . . . . . . . . . . 6-114
Electrical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-114
Add-On Electrical Equipment . . . . . . . . . . . . . . . . . 6-114
Headlamp Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-115
Windshield Wiper Fuses . . . . . . . . . . . . . . . . . . . . . . 6-115 Power Windows and Other Power Options . . . 6-115
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . . 6-115
Underhood Fuse Block . . . . . . . . . . . . . . . . . . . . . . . 6-116
Rear Underseat Fuse Block . . . . . . . . . . . . . . . . . . 6-120
Capacities and Specifications . . . . . . . . . . . . . . . . . .6-128
6-3
Page 355 of 528

Black plate (5,1)Cadillac STS Owner Manual - 2011
California Proposition 65 Warning
Most motor vehicles, including this one, contain and/or
emit chemicals known to the State of California to
cause cancer and birth defects or other reproductive
harm. Engine exhaust, many parts and systems, many
fluids, and some component wear by-products contain
and/or emit these chemicals.
California Perchlorate Materials
Requirements
Certain types of automotive applications, such as
airbag initiators, seat belt pretensioners, and lithium
batteries contained in remote keyless transmitters,
may contain perchlorate materials. Special handling
may be necessary. For additional information, see
www.dtsc.ca.gov/hazardouswaste/perchlorate.
Doing Your Own Service Work
{WARNING:
You can be injured and the vehicle could be
damaged if you try to do service work on a vehicle
without knowing enough about it.
.Be sure you have sufficient knowledge,
experience, the proper replacement parts,
and tools before attempting any vehicle
maintenance task.
.Be sure to use the proper nuts, bolts, and
other fasteners. English and metric fasteners
can be easily confused. If the wrong fasteners
are used, parts can later break or fall off. You
could be hurt.
If doing some of your own service work, use the proper
service manual. It tells you much more about how to
service the vehicle than this manual can. To order the
proper service manual, see Service Publications
Ordering Information on page 8‑17.
6-5
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 465 of 528

Black plate (115,1)Cadillac STS Owner Manual - 2011
The vehicle has an airbag system. Before attempting to
add anything electrical to the vehicle, seeServicing
Your Airbag-Equipped Vehicle
on page 2‑70and
Adding Equipment to Your Airbag-Equipped Vehicleon
page 2‑71.
Headlamp Wiring
The headlamp wiring is protected by fuses in the fuse
block. An electrical overload will cause the lamps to turn
off. If this happens, have the headlamp wiring checked
right away.
Windshield Wiper Fuses
The windshield wiper motor is protected by an internal
circuit breaker. If the wiper motor overheats due to
heavy snow, the wipers will stop until the motor cools
and will then restart.
Power Windows and Other Power
Options
Circuit breakers in the fuse block protect the power
windows and other power accessories. When the
current load is too heavy, the circuit breaker opens and
closes, protecting the circuit until the problem is fixed or
goes away.
Fuses and Circuit Breakers
The wiring circuits in the vehicle are protected from
short circuits by a combination of fuses, circuit breakers
and fusible thermal links. This greatly reduces the
chance of fires caused by electrical problems.
Look at the silver-colored band inside the fuse. If the
band is broken or melted, replace the fuse. Be sure you
replace a bad fuse with a new one of the identical size
and rating.
Fuses of the same amperage can be temporarily
borrowed from another fuse location, if a fuse goes out.
Replace the fuse as soon as you can.
6-115
Page 466 of 528
Black plate (116,1)Cadillac STS Owner Manual - 2011
Underhood Fuse Block
6-116
Page 467 of 528

Black plate (117,1)Cadillac STS Owner Manual - 2011
The underhood fuse block is located in the front of the
engine compartment on the passenger side of the
vehicle. SeeEngine Compartment Overview
on
page 6‑13for more information on location and
removal procedure for the front compartment underhood
sights shields.
To access the fuses, push in the tabs located on each
side of the fuse block cover, then lift the cover off.
Notice: Spilling liquid on any electrical component
on the vehicle may damage it. Always keep the
covers on any electrical component.
Fuses JCase Usage
ABS MTR ABS Module- ABS Module-Stabilitrak AFS Active Front Steering
BLWR Blower Motor
FAN 1 Cooling Fan-Low Speed
FAN 2 Cooling Fan-High Speed
LPDB 1 Driver Side Rear Fuse Block
LPDB 2 Driver Side Rear Fuse Block
RPDB 1 Passenger Side Rear Fuse Block
RPDB 2 Passenger Side Rear Fuse Block
Fuses JCase Usage
SPARE Spare
SPARE Spare
STRTR Starter
Fuses MiniUsage
A/C CLTCH Air Conditioning Compressor Clutch
ABS ABS Module-Stabilitrak
ABS IGN Antilock Brake Controller
AUX OUTLET Rear Accessory Power Outlet BRK
VAC PUMP Brake Vacuum Pump
CCP Climate Control Panel
CCP/RLY COILS Climate Control Panel, Headlamp
Level Control, Active Cruise Control,
Relay Coils, Starter, Front Blower
ECM 1 Engine Control Module (ECM)
ECM/TCM BATT ECM, Transmission Control
Module (TCM)
ECM/TCM IGN ECM, TCM, Instrument Panel Cluster
6-117
Page 468 of 528

Black plate (118,1)Cadillac STS Owner Manual - 2011
Fuses MiniUsage
EKM/I/P MDLEasy Key Module (EKM), Instrument
Panel Module (I/P MDL)
EVEN COILS Even Ignition Coils, Even Fuel
Injectors
FOG LAMP Front Fog Lamps
FRT PWR OUTLET Front Accessory Power Outlet
FUEL COOL Fuel Cooling HORN Horn
HTD
WASH/AQS Heated Headlamp Washer, Air Quality
Sensor
HUD Heads-Up Display, Steering Column
Switch
I/BEAM IntelliBeam Relay
I/P MDL/ALDL Instrument Panel Module, Assembly
Line Data Link Connector
LIC DIM License Plate, Instrument Panel
Dimming
LT HI BEAM Driver Side High Beam Headlamp
LT LO BEAM Driver Side Low Beam Headlamp
Fuses Mini Usage
LT PRKDriver Side Park Lamp/Driver Side
Taillamp
ODD COILS Odd Ignition Coils, Odd Fuel Injectors
POST O2 SNSR Post Oxygen Sensor PRE O2 SNSR Pre Oxygen Sensor, CAM Sensors
RAIN
SNSR/TPM Rain Sensor, Relay Coil:
Headlamp Wash
RT HI BEAM Passenger Side High Beam
Headlamp
RT LO BEAM Passenger Side Low Beam Headlamp
RT PRK Passenger Side Park Lamp,
Passenger Side Taillamp
SPARE Spare
SPARE Spare
SPARE Spare
SPARE Spare
SPARE Spare
SPARE Spare
SPARE Spare
6-118
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