2009 CADILLAC STS cooling

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 5-12for 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/retailer for service.
5-29

{CAUTION:
Steam and scalding liquids from a hot cooling
system can blow out and burn you badly. They are
under pressure, and if you turn the coolant surge
tank pressure cap — even a little — they can
come out at high speed. Never turn the cap when
the cooling system, including the coolant surge
tank pressure cap, is hot. Wait for the cooling
system and coolant surge tank pressure cap to
cool if you ever have to turn the pressure cap.
{CAUTION:
An electric engine cooling fan under the hood can
start up even when the engine is not running and
can cause injury. Keep hands, clothing, and tools
away from any underhood electric fan.If no coolant is visible in the surge tank, add coolant as
follows:
1. Remove the coolant surge tank pressure cap when
the cooling system, including the coolant surge tank
pressure cap and upper radiator hose, is no longer
hot. Turn the pressure cap slowly counterclockwise
about one-quarter of a turn. If you hear a hiss, wait
for that to stop. A hiss means there is still some
pressure left.
2. Then keep turning the pressure cap slowly, and
remove it.
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3. Fill the coolant surge tank with the proper
DEX-COOL®coolant mixture, to slightly above
the FULL COLD/FROID line on the side of
the coolant surge tank.4. With the coolant surge tank pressure cap off,
start the engine and let it run until you can feel
the upper radiator hose getting hot. The upper
radiator hose is the largest of the hoses which
comes out of the radiator, on the passenger
side of the vehicle. Watch out for the engine
cooling fans.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge tank
until the level reaches the FULL COLD/FROID
line on the side of the coolant surge tank.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
Start the engine and allow it to warm up.
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You may decide not to lift the hood when this warning
appears, but instead get service help right away.
SeeRoadside Service on page 7-7.
If you do decide to lift the hood, make sure the vehicle
is parked on a level surface.
Then check to see if the engine cooling fans are
running. If the engine is overheating, both fans should
be running. If they are not, do not continue to run
the engine and have the vehicle serviced.
Notice:Engine damage from running your engine
without coolant is not covered by your warranty. See
Overheated Engine Protection Operating Mode on
page 5-36for information on driving to a safe place
in an emergency.
Notice:If the engine catches re while driving
with no coolant, the vehicle can be badly damaged.
The costly repairs would not be covered by the
vehicle warranty. SeeOverheated Engine Protection
Operating Mode on page 5-36for information on
driving to a safe place in an emergency.If Steam Is Coming From The Engine
Compartment
{CAUTION:
Steam from an overheated engine can burn you
badly, even if you just open the hood. Stay away
from the engine if you see or hear steam coming
from it. Turn it off and get everyone away from the
vehicle until it cools down. Wait until there is no sign
of steam or coolant before you open the hood.
If you keep driving when the vehicles engine is
overheated, the liquids in it can catch re. You or
others could be badly burned. Stop the engine if it
overheats, and get out of the vehicle until the
engine is cool.
SeeOverheated Engine Protection Operating Mode
on page 5-36for information on driving to a safe
place in an emergency.
5-35

If you need to replace any of your wheels, wheel bolts,
wheel nuts, or Tire Pressure Monitor System (TPMS)
sensors, replace them only with new GM original
equipment parts. This way, you will be sure to have
the right wheel, wheel bolts, wheel nuts, and TPMS
sensors for your vehicle.
{CAUTION:
Using the wrong replacement wheels, wheel bolts,
or wheel nuts on your vehicle can be dangerous.
It could affect the braking and handling of your
vehicle, make your tires lose air and make you
lose control. You could have a collision in which
you or others could be injured. Always use the
correct wheel, wheel bolts, and wheel nuts for
replacement.Notice:The wrong wheel can also cause problems
with bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper height,
vehicle ground clearance, and tire or tire chain
clearance to the body and chassis.
SeeChanging a Flat Tire on page 5-104for more
information.
Used Replacement Wheels
{CAUTION:
Putting a used wheel on the vehicle is dangerous.
You cannot know how it has been used or how
far it has been driven. It could fail suddenly and
cause a crash. If you have to replace a wheel,
use a new GM original equipment wheel.
5-80

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 5-12for 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 components
on the vehicle may damage it. Always keep the
covers on any electrical component.
Fuses JCase Usage
ABS MTRABS 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 Mini Usage
A/C CLTCH Air Conditioning Compressor Clutch
ABS ABS Module-Stabilitrak
ABS IGN Antilock Brake Controller
AUX OUTLET Rear Accessory Power Outlet
BRK VAC
PUMPBrake Vacuum Pump
CCP Climate Control Panel
CCP/RLY
COILSClimate Control Panel, Headlamp
Level Control, Active Cruise Control,
Relay Coils, Starter, Front Blower
ECM 1 Engine Control Module (ECM)
ECM/TCM
BATTECM, Transmission Control
Module (TCM)
ECM/TCM IGNECM, TCM, Instrument Panel
Cluster
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Fuses Mini Usage
EKM/I/P MDLEasy Key Module (EKM), Instrument
Panel Module (I/P MDL)
EVEN COILSEven Ignition Coils, Even Fuel
Injectors
FOG LAMP Front Fog Lamps
FRT PWR
OUTLETFront Accessory Power Outlet
FUEL COOL Fuel Cooling
HORN Horn
HTD
WASH/AQSHeated Headlamp Washer,
Air Quality Sensor
HUDHeads-Up Display, Steering Column
Switch
I/BEAM IntelliBeam Relay
I/P MDL/ALDLInstrument Panel Module, Assembly
Line Data Link Connector
LIC DIMLicense Plate, Instrument Panel
Dimming
LT HI BEAM Driver Side High Beam Headlamp
LT LO BEAM Driver Side Low Beam Headlamp
LT PRKDriver Side Park Lamp/Driver Side
TaillampFuses Mini Usage
ODD COILSOdd Ignition Coils, Odd Fuel
Injectors
POST O2
SNSRPost Oxygen Sensor
PRE O2 SNSR Pre Oxygen Sensor, CAM Sensors
RAIN
SNSR/TPMRain Sensor, Relay Coil:
Headlamp Wash
RT HI BEAMPassenger Side High Beam
Headlamp
RT LO BEAMPassenger Side Low Beam
Headlamp
RT PRKPassenger Side Park Lamp,
Passenger Side Taillamp
SPARE Spare
SPARE Spare
SPARE Spare
SPARE Spare
SPARE Spare
SPARE Spare
SPARE Spare
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Fuses Mini Usage
V/CHKInstrument Panel Module-Voltage
Check
WPR Wipe/Wash Module Assembly
WPR SW/VICS Rain Sensor, Wiper Switch
Relays Usage
A/C CMPRSR
CLTCHAir Conditioning Compressor Clutch
ACCYAccessory, Rain Sensor, Headlamp
Washer Relay Coil, Windshield
Wiper/Washer Module
BRK VAC
PUMPBrake 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/HIDLow Beam Headlamp, High Intensity
Discharge (HID)
PRK LAMPParking Lamps, Instrument Panel
Dimming, Rear License Plate Lamps
PWR/TRN Engine Controls
RUN CRNKHeated 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
BreakersUsage
HDLP WASHHeadlamp Washer Motor
(Circuit Breaker)
5-127