cooling CADILLAC STS 2006 1.G Owner's Manual

{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
If no coolant is visible in the surge tank, add coolant
as follows:
1. You can 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.
5-35

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’s 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. If the CHECK
COOLANT LEVEL message does not appear on the
Driver Information Center (DIC), the coolant is at
the proper ll level. If the CHECK COOLANT LEVEL
message does appear, repeat Steps 1 to 3 then reinstall
the pressure cap, or see your GM dealer.
5-36

How to Add Coolant to the
Intercooler System Fill Neck
(4.4L V8 STS-V Engine Only)
If you have not found a problem yet, turn the engine off
and allow it to cool down, then check to see if coolant is
visible within the horizontal tube section of the ll neck.
If coolant is not visible, add a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant to the ll neck.
Be sure the Intercooler System, including the Intercooler
System pressure cap, is cool before doing so. See
Engine Coolant on page 5-26for more information.
{CAUTION:
Turning the Intercooler System pressure cap
when the engine and intercooler are hot can
allow steam and scalding liquids to blow out
and burn you badly. Never turn the Intercooler
System pressure cap, even a little, when the
engine and intercooler are hot.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.
Notice:In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
5-37

If you need to replace any of your wheels, wheel bolts,
or wheel nuts, replace them only with new GM
original equipment parts. This way, you will be sure to
have the right wheel, wheel bolts, and wheel nuts
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 (STS Only) on page 5-83for
more information.
Used Replacement Wheels
{CAUTION:
Putting a used wheel on your 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.
5-77

Fuses Usage
ECM/TCMEngine Control Module,
Transmission Control Module,
Easy Key Module, Instrument
Panel Cluster
SPARE Spare
SPARE Spare
LT PARKDriver’s Side Park Lamp, Driver’s
Side Taillamp
LIC DIMMINGLicense Plate, Instrument
Panel Dimming
IPM ALDLInstrument Panel Module Assembly
Line Data Link Connector
HUDHeads-Up Display, Column
Lock Module
V8 ECMV8 Engine Control Module,
Evap. Solenoid
ABS Anti-lock Brake Controller
STR RLY Starter Relay
WASH
NOZ/AQSHeated Washer Nozzles, Air
Quality SensorFuses Usage
ODD COILSOdd Ignition Coils, Odd
Fuel Injectors
TCM IPCTransmission Control Module,
Instrument Panel, Engine Control
SPARE Spare
MAF Mass Air Flow Sensor
HIGH FAN Cooling Fan - High Speed
LOW FAN Cooling Fan - Low Speed
RT PARKPassenger’s Side Park Lamp,
Right Taillamp
HORN Horn
LT HI BEAM Driver’s Side Headlamp High Beam
LT LOW BEAM Driver’s Side Headlamp Low Beam
RT LOW BEAMPassenger’s Side Headlamp
Low Beam
RT HI BEAM Right Headlamp High Beam
HFV6 ECMHigh Feature V6 Engine
Control Module
5-108

Relays Usage
HDLP WASH
RELAY
JUMPER -OPTHeadlamp Washer
STARTER
RELAY MINIStarter
SPARE Spare
FOG LAMP
RELAY MICROFog Lamps
CMP CLU
RELAY MICROAir Conditioning Compressor Clutch
BLOWER
RELAY MINIFront Blower Motor
POWERTRAIN
RELAY MICROEngine Controls
RUN/CRANK
RELAY MICROIgnition 1, Starter, Washer Nozzle,
Air Quality, Anti-lock Brake System,
Climate Control Panel, Transmission
Control Module, Instrument Panel
Cluster, Mass Airow Sensor,
Engine Control Module
LOW SPEED
FAN RELAY
MINICooling Fan Low SpeedRelays Usage
ACCESSORY
RELAY MINIIgnition 3, Rain Sensor, Headlamp
Washer, Windshield Wiper/Washer
Module, Infotainment (Export Only)
PARK LAMP
RELAY MICROParking Lamps, Instrument Panel
Dimming, Rear License Plate Lamps
HIGH BEAM
RELAY MICROHeadlamp High Beam
LOW BEAM
RELAY/HID
MINI-OPTLow Beam/High Intensity Discharge
HIGH
SPEED FAN
RELAY MINICooling Fan High Speed
S/P FAN
RELAY MINICooling Fan Series/Parallel
HORN RELAY
MICROHorn
SPARE Spare
Circuit
BreakersUsage
HDLP WASH
C/B -OPTHeadlamp Washer (If Equipped)
5-109

Fuses Usage
REAR FOG
LAMP (OPT)Rear Fog Lamps (Option)
AFTERBOIL/
DIFF
PUMP (OPT)After Boil, Rear Differential
Cooling Pump
RIM Ignition to Rear Integration Module
JOINT
CONNECTORJoint Connector
Relays Usage
SPARE Spare
REAR DEFOG
RELAY MINIRear Defog
FUEL PUMP
RELAY MICROFuel Pump
REAR FOG
LAMP RLY
MICRO (OPT)Rear Fog Lamps (Option)
Relays Usage
STOP LAMP
RELAY MICROStoplamps
INT LAMP
RELAY MICROInterior Lamps
RUN/CRANK
RELAY MICROIgnition 1
AFTERBOIL/
DIFF PUMP
RELAY
MICRO (OPT)After Boil, Rear Differential Cooling
Pump (Option)
Circuit
BreakersUsage
WINDOW
MTRS C/BPower Window Motors Circuit
Breaker
Diodes Usage
TRUNK DIODE Trunk Release
5-115

Capacities and Specications
The following approximate capacities are given in English and metric conversions. SeeRecommended Fluids and
Lubricants on page 6-12for more information.
ApplicationCapacities
English Metric
Air Conditioning Refrigerant R134a 1.38 lbs 0.63 kg
Cooling System
3.6L V6 11.7 qt 11.1 L
4.4L V8 (V-Series) 13.4 qt 12.7 L
4.6L V8 12.5 qt 11.8 L
Intercooler System 4.4L Engine 2.6 qt 2.5 L
Engine Oil with Filter
3.6L V6 6.0 qt 5.7 L
4.4L V8 (V-Series) 9.0 qt 8.5 L
4.6L V8 8.0 qt 7.6 L
Fuel Tank 17.5 gal 66.2 L
Transmission
5-Speed Automatic 9.5 qt 9.0 L
6-Speed Automatic (V-Series) 6.5 qt 6.2 L
Wheel Nut Torque 100 lb ft 140Y
All capacities are approximate. When adding, be sure to ll to the approximate level as recommended in this
manual. Recheck the uid level after lling.
5-116

Scheduled Maintenance
Service MaintenanceIMaintenanceII
Change engine oil and lter. SeeEngine Oil on page 5-18. Reset oil life system.
SeeEngine Oil Life System on page 5-22.An Emission Control Service.••
Visually check for any leaks or damage.See footnote (k).••
Inspect engine air cleaner lter. If necessary, replace lter. SeeEngine Air
Cleaner/Filter on page 5-24.See footnote (m).•
Check tires for ination pressures and wear. SeeTires on page 5-56. If tire
rotation is recommended for your vehicle, rotate tires. SeeTire Inspection and
Rotation on page 5-70and “Tire Wear Inspection” inAt Least Once a Month
on page 6-9.••
Inspect brake system.See footnote (a).••
Check engine coolant and windshield washer uid levels. If you have the 4.4L V8
supercharged engine, check intercooler uid level. Add uid as needed.••
Perform any needed additional services. See “Additional Required Services”
in this section.••
Inspect suspension and steering components.See footnote (b).•
Inspect engine cooling system.See footnote (c).•
Inspect wiper blades.See footnote (d).•
Inspect restraint system components.See footnote (e).•
Lubricate body components.See footnote (f).•
Check transmission uid level and add uid as needed.•
Replace passenger compartment air lter.See footnote (g).•
6-5

Additional Required Services (cont’d)
Service and Miles (Kilometers)25,000
(40 000)50,000
(80 000)75,000
(120 000)100,000
(160 000)125,000
(200 000)150,000
(240 000)
Engine cooling system service
(or every ve years, whichever occurs
rst).An Emission Control Service.
See footnote (j).•
Inspect engine accessory drive belt.
An Emission Control Service.
See footnote (n).•
Maintenance Footnotes
†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.
(a)Visually inspect brake lines and hoses for proper
hook-up, binding, leaks, cracks, chang, etc. Inspect
disc brake pads for wear and rotors for surface
condition. Inspect other brake parts, including calipers,
parking brake, etc.(b)Visually inspect front and rear suspension and
steering system for damaged, loose, or missing parts or
signs of wear. Inspect power steering lines and hoses
for proper hook-up, binding, leaks, cracks, chang, etc.
(c)Visually inspect hoses and have them replaced if they
are cracked, swollen, or deteriorated. Inspect all pipes,
ttings, and clamps; replace with genuine GM parts as
needed. To help ensure proper operation, a pressure test
of the cooling system and pressure cap and cleaning the
outside of the radiator and air conditioning condenser is
recommended at least once a year.
(d)Visually inspect wiper blades for wear or cracking.
Replace wiper blades that appear worn or damaged
or that streak or miss areas of the windshield.
6-7