2008 CADILLAC STS fuel cap

Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-2
Rear Seats
............................................... 1-7
Safety Belts
.............................................. 1-8
Child Restraints
.......................................1-28
Airbag System
.........................................1-51
Restraint System Check
............................1-66
Features and Controls..................................... 2-1
Keys
........................................................ 2-3
Doors and Locks
......................................2-14
Windows
.................................................2-19
Theft-Deterrent Systems
............................2-22
Starting and Operating Your Vehicle
...........2-27
Mirrors
....................................................2-40
Object Detection Systems
..........................2-45
OnStar
®System
......................................2-48
Universal Home Remote System
................2-51
Storage Areas
.........................................2-58
Sunroof
..................................................2-58
Vehicle Personalization
.............................2-60
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Climate Controls
......................................3-48
Warning Lights, Gages, and Indicators
........3-57
Driver Information Center (DIC)
..................3-74
Audio System(s)
.......................................3-98Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
...................................................4-31
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-3
Fuel
......................................................... 5-5
Checking Things Under the Hood
...............5-10
All-Wheel Drive
........................................5-50
Rear Axle
...............................................5-51
Front Axle
...............................................5-52
Headlamp Aiming
.....................................5-53
Bulb Replacement
....................................5-54
Windshield Replacement
...........................5-55
Windshield Wiper Blade Replacement
.........5-55
Tires
......................................................5-57
Appearance Care
...................................5-107
Vehicle Identication
...............................5-116
Electrical System
....................................5-116
Capacities and Specications
...................5-128
Maintenance Schedule..................................... 6-1
Maintenance Schedule
................................ 6-2
Customer Assistance Information.................... 7-1
Customer Assistance and Information
........... 7-2
Reporting Safety Defects
...........................7-14
Vehicle Data Recording and Privacy
...........7-16
Index................................................................ 1
2008 Cadillac STS/STS-V Owner ManualM

Engine Coolant Heater
The engine coolant heater, if available, can help in cold
weather conditions at or below 0°F (−18°C) for easier
starting and better fuel economy during engine warm-up.
Plug in the coolant heater at least four hours before
starting your vehicle. An internal thermostat in the
plug-end of the cord may exist which will prevent
engine coolant heater operation at temperatures
above 0°F (−18°C).
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
For the 3.6L V6 and 4.4L V8 engine, the cord is
located in the front of the engine compartment,
on the passenger’s side of the vehicle.
For the 4.6L V8 engine, the cord is located in the
engine compartment on the driver’s side of the
vehicle near the inner fender and above the strut.
3. You must remove the plastic cap to access the plug.
4. Plug it into a normal, grounded 110-volt AC outlet.
{CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the
wrong kind of extension cord could overheat
and cause a re. You could be seriously
injured. Plug the cord into a properly grounded
three-prong 110-volt AC outlet. If the cord will
not reach, use a heavy-duty three-prong
extension cord rated for at least 15 amps.
5. Before starting the engine, be sure to unplug and
store the cord as it was before to keep it away
from moving engine parts. If you do not, it could be
damaged.
How long should you keep the coolant heater plugged
in? The answer depends on the outside temperature, the
kind of oil you have, and some other things. Instead
of trying to list everything here, we ask that you contact
your dealer in the area where you will be parking
your vehicle. The dealer can give you the best advice
for that particular area.
2-31

If the Light Is Flashing
The following can prevent more serious damage to
your vehicle:
Reduce vehicle speed.
Avoid hard accelerations.
Avoid steep uphill grades.
If the light stops ashing and remains on steady,
see “If the Light Is On Steady” following.
If the light continues to ash, when it is safe to do so,
stop the vehicle. Find a safe place to park the vehicle.
Turn the engine off, wait at least 10 seconds and restart
the engine. If the light remains on steady, see “If the
Light Is On Steady” following. If the light is still ashing,
follow the previous steps, and see your dealer/retailer
for service as soon as possible.
If the Light Is On Steady
You might be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install the
cap. SeeFilling the Tank on page 5-7. The diagnostic
system can determine if the fuel cap has been left off or
improperly installed. A loose or missing fuel cap allows
fuel to evaporate into the atmosphere. A few driving trips
with the cap properly installed should turn the light off.Did you just drive through a deep puddle of water?
If so, your vehicle’s electrical system might be wet. The
condition is usually corrected when the electrical system
dries out. A few driving trips should turn the light off.
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 5-5. Poor fuel quality causes
the engine not to run as efficiently as designed. You
might notice this as stalling after start-up, stalling when
you put the vehicle into gear, misring, hesitation on
acceleration, or stumbling on acceleration — these
conditions might go away once the engine is warmed up.
This will be detected by the system and cause the light
to turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at least
one full tank of the proper fuel to turn the light off.
If none of the above steps have made the light turn
off, your dealer/retailer can check the vehicle. Your
dealer/retailer has the proper test equipment and
diagnostic tools to x any mechanical or electrical
problems that might have developed.
3-69

Fuel Gage
The fuel gage shows
approximately how much
fuel is in the fuel tank.
It works only when
the engine is on.
If the fuel supply gets low, the “FUEL LEVEL LOW”
message will appear on the Driver Information Center
(DIC) and a single chime will sound. SeeDIC Warnings
and Messages on page 3-80for more information.All of the following situations are normal and do not
indicate that anything is wrong with the fuel gage:At the gas station the gas pump shuts off before
the gage reads full.
The gage may change when you turn, stop quickly
or accelerate quickly.
It takes a little more or less fuel to ll the tank than
the gage indicated. For example, the gage may
have indicated that the tank was half full, but
it actually took a little more or less than half the
tank’s capacity to ll the tank.
3-73

CHANGE ENGINE OIL SOON
This message displays when the engine oil needs to be
changed. See your dealer/retailer. SeeEngine Oil on
page 5-18andScheduled Maintenance on page 6-4for
more information.
After resetting the CHANGE ENGINE OIL SOON
message by clearing it from the display, reset the engine
oil life system separately. For more information on
resetting the engine oil life system, seeEngine Oil Life
System on page 5-21.
CHECK BRAKE FLUID
This message displays if the ignition is on to inform the
driver that the brake uid level is low. Have the brake
system serviced by your dealer/retailer as soon as
possible. SeeBrake System Warning Light on page 3-64
for more information.
CHECK GAS CAP
This message displays when the fuel cap has not been
fully tightened. Recheck the fuel cap to ensure that it
is on and tightened properly.
CHECK TIRE PRESSURE
This message displays when the pressure in one or
more of the vehicle’s tires needs to be checked. If a tire
pressure message appears on the DIC, stop as soon
as you can. Have the tire pressures checked and set
to those shown on the Tire Loading Information
label. SeeTires on page 5-57,Loading Your Vehicle on
page 4-26, andInflation - Tire Pressure on page 5-66.
The DIC also shows the tire pressure values. See
DIC Operation and Displays on page 3-74. If the tire
pressure is low, the low tire pressure warning light
comes on. SeeTire Pressure Light on page 3-67.
CHECK WASHER FLUID
This symbol appears
with this message.
This message displays when the windshield washer
uid is low. Fill the windshield washer uid reservoir
as soon as possible. SeeWindshield Washer Fluid
on page 5-40for more information.
3-83

Certication Label
A vehicle specic Certication label is attached to
either the driver’s door edge or the lower center
pillar on the driver’s side of the vehicle. This label
shows the gross weight capacity of your vehicle,
called the Gross Vehicle Weight Rating (GVWR).
The GVWR includes the weight of the vehicle,
all occupants, fuel, and cargo. The Certication
label also shows the maximum weights for
the front and rear axles, called the Gross Axle
Weight Rating (GAWR). Never exceed the GVWR
or the GAWR for either the front or rear axle.
{CAUTION:
Do not load your vehicle any heavier than
the Gross Vehicle Weight Rating (GVWR),
or either the maximum front or rear Gross
Axle Weight Rating (GAWR). If you do,
parts on your vehicle can break, and it
can change the way your vehicle handles.
These could cause you to lose control
and crash. Also, overloading can shorten
the life of your vehicle.
Notice:Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.
4-30

Towing a Trailer (Vehicles With
Heavy Duty Cooling)
{CAUTION:
If you do not use the correct equipment and
drive properly, you can lose control when you
pull a trailer. For example, if the trailer is too
heavy, the brakes may not work well — or even
at all. You and your passengers could be
seriously injured. You may also damage your
vehicle; the resulting repairs would not be
covered by your warranty. Pull a trailer only if
you have followed all the steps in this section.
Ask your dealer/retailer for advice and
information about towing a trailer with your
vehicle.
Vehicles with heavy duty cooling can tow a trailer if it is
equipped with the proper trailer towing equipment.
To identify the trailering capacity of your vehicle, you
should read the information in “Weight of the Trailer” that
appears later in this section. Trailering is different
than just driving your vehicle by itself. Trailering meanschanges in handling, acceleration, braking, durability
and fuel economy. Successful, safe trailering takes
correct equipment, and it has to be used properly.
That is the reason for this part. In it are many
time-tested, important trailering tips and safety rules.
Many of these are important for your safety and that of
your passengers. So please read this section carefully
before you pull a trailer.
Load-pulling components such as the engine,
transmission, wheel assemblies and tires are forced to
work harder against the drag of the added weight.
The engine is required to operate at relatively higher
speeds and under greater loads, generating extra heat.
Also, the trailer adds considerably to wind resistance,
increasing the pulling requirements.
If You Do Decide To Pull A Trailer
If you do, here are some important points:
There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will be legal, not only where you live
but also where you will be driving. A good source
for this information can be state or provincial police.
Consider using a sway control. You can ask a hitch
dealer/retailer about sway controls.
4-34

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-3
California Perchlorate Materials Requirements.....5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside
of Your Vehicle...........................................5-4
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-11
Engine Oil...................................................5-18
Engine Oil Life System..................................5-21
Engine Air Cleaner/Filter................................5-23
Automatic Transmission Fluid.........................5-25
Engine Coolant.............................................5-25
Coolant Surge Tank Pressure Cap..................5-29
Engine Overheating.......................................5-29
Overheated Engine Protection Operating Mode . . .5-31Cooling System............................................5-32
Power Steering Fluid.....................................5-39
Windshield Washer Fluid................................5-40
Brakes........................................................5-41
Battery........................................................5-44
Jump Starting...............................................5-45
All-Wheel Drive..............................................5-50
Rear Axle.......................................................5-51
Front Axle......................................................5-52
Headlamp Aiming...........................................5-53
Bulb Replacement..........................................5-54
High Intensity Discharge (HID) Lighting............5-54
Halogen Bulbs..............................................5-54
Back-Up Lamps............................................5-54
Replacement Bulbs.......................................5-55
Windshield Replacement.................................5-55
Windshield Wiper Blade Replacement..............5-55
Tires..............................................................5-57
Winter Tires.................................................5-58
Tire Sidewall Labeling...................................5-59
Tire Terminology and Denitions.....................5-62
Run-Flat Tires (STS-V)..................................5-65
Ination - Tire Pressure.................................5-66
High-Speed Operation...................................5-68
Section 5 Service and Appearance Care
5-1