2009 CADILLAC STS octane

This light comes on during a malfunction in one of
two ways:
Light Flashing:A misre condition has been detected.
A misre increases vehicle emissions and could damage
the emission control system on the vehicle. Diagnosis
and service might be required.
The following can prevent more serious damage to the
vehicle:
Reduce vehicle speed.
Avoid hard accelerations.
Avoid steep uphill grades.
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 key off, wait at least 10 seconds, and restart
the engine. If the light is still ashing, follow the previous
steps and see your dealer/retailer for service as soon
as possible.
Light On Steady:An emission control system
malfunction has been detected on the vehicle.
Diagnosis and service might be required.An emission system malfunction might be corrected by
doing the following:
Make sure the fuel cap is fully installed. SeeFilling
the Tank on page 5-8. 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.
If the vehicle has been driven through a deep puddle
of water, the 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.
Make sure to fuel the vehicle with quality fuel. Poor
fuel quality causes the engine not to run as efficiently
as designed and may cause: stalling after start-up,
stalling when the vehicle is changed into gear,
misring, hesitation on acceleration, or stumbling on
acceleration. These conditions might go away once
the engine is warmed up.
If one or more of these conditions occurs, change the
fuel brand used. It will require at least one full tank of
the proper fuel to turn the light off.
SeeGasoline Octane on page 5-5.
3-67

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-4
California Perchlorate Materials Requirements......5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of
the Vehicle.................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-7
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-18
Engine Oil Life System..................................5-21
Engine Air Cleaner/Filter................................5-23
Automatic Transmission Fluid.........................5-25
Cooling System............................................5-26
Engine Coolant.............................................5-27
Coolant Surge Tank Pressure Cap..................5-34
Engine Overheating.......................................5-34Overheated Engine Protection
Operating Mode........................................5-36
Power Steering Fluid.....................................5-37
Windshield Washer Fluid................................5-38
Brakes........................................................5-39
Battery........................................................5-42
Jump Starting...............................................5-42
All-Wheel Drive..............................................5-47
Rear Axle.......................................................5-48
Front Axle......................................................5-49
Headlamp Aiming...........................................5-50
Bulb Replacement..........................................5-51
High Intensity Discharge (HID) Lighting............5-51
Halogen Bulbs..............................................5-51
Back-Up Lamps............................................5-52
Replacement Bulbs.......................................5-52
Windshield Replacement.................................5-52
Windshield Wiper Blade Replacement..............5-52
Tires..............................................................5-54
Winter Tires.................................................5-55
Tire Sidewall Labeling...................................5-56
Tire Terminology and Denitions.....................5-59
Run-Flat Tires (STS-V)..................................5-62
Ination - Tire Pressure.................................5-64
High-Speed Operation...................................5-65
Tire Pressure Monitor System.........................5-66
Tire Pressure Monitor Operation.....................5-68
Section 5 Service and Appearance Care
5-1

This vehicle has an airbag system. Before attempting
to do your own service work, seeServicing Your
Airbag-Equipped Vehicle on page 1-64.
Keep a record with all parts receipts and list the
mileage and the date of any service work performed.
SeeMaintenance Record on page 6-18.
Adding Equipment to the Outside of
the Vehicle
Things added to the outside of the vehicle can affect the
airow around it. This can cause wind noise and can
affect fuel economy and windshield washer performance.
Check with your dealer/retailer before adding equipment
to the outside of the vehicle.
Fuel
Use of the recommended fuel is an important part of
the proper maintenance of this vehicle. To help keep the
engine clean and maintain optimum vehicle performance,
we recommend the use of gasoline advertised as TOP
TIER Detergent Gasoline.
The 8th digit of the Vehicle Identication Number (VIN)
shows the code letter or number that identies the
vehicle’s engine. The VIN is at the top left of the
instrument panel. SeeVehicle Identification Number
(VIN) on page 5-122.
Gasoline Octane
If the vehicle has the 3.6L V6 engine (VIN Code V), use
regular unleaded gasoline with a posted octane rating
of 87 or higher. If the octane rating is less than 87, you
might notice an audible knocking noise when you drive,
commonly referred to as spark knock. If this occurs, use a
gasoline rated at 87 octane or higher as soon as possible.
If you are using gasoline rated at 87 octane or higher and
you hear heavy knocking, the engine needs service.
If the vehicle has the 4.6L V8 engine (VIN Code A), use
premium unleaded gasoline with a posted octane rating
of 91 or higher. You can also use regular unleaded
gasoline rated at 87 octane or higher, but the vehicle’s
acceleration could be slightly reduced, and you might
notice a slight audible knocking noise, commonly referred
to as spark knock. If the octane is less than 87, you might
notice a heavy knocking noise when you drive. If this
occurs, use a gasoline rated at 87 octane or higher as
soon as possible. Otherwise, you could damage the
engine. If you are using gasoline rated at 87 octane or
higher and you hear heavy knocking, the engine needs
service.
5-5

If the vehicle has the 4.4L V8 engine (VIN Code D), use
premium unleaded gasoline with a posted octane rating
of 91 or higher. For best performance, use premium
unleaded gasoline with a posted octane rating of 93.
In an emergency, you can use regular unleaded gasoline
with an octane rating of 87 or higher. If 87 octane fuel is
used, do not perform any aggressive driving maneuvers
such as wide open throttle applications. You might also
hear audible spark knock during acceleration. Rell the
tank with premium fuel as soon as possible to avoid
damaging the engine. If you are using gasoline rated
at 91 octane or higher and you hear heavy knocking,
the engine needs service.
Gasoline Specications
At a minimum, gasoline should meet ASTM specication
D 4814 in the United States or CAN/CGSB-3.5 or 3.511 in
Canada. Some gasolines contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend against the use of
gasolines containing MMT. SeeAdditives on page 5-7
for additional information.
California Fuel
If the vehicle is certied to meet California Emissions
Standards, it is designed to operate on fuels that meet
California specications. See the underhood emission
control label. If this fuel is not available in states adopting
California emissions standards, the vehicle will operate
satisfactorily on fuels meeting federal specications, but
emission control system performance might be affected.
The malfunction indicator lamp could turn on and the
vehicle might fail a smog-check test. SeeMalfunction
Indicator Lamp on page 3-66. If this occurs, return to your
authorized dealer/retailer for diagnosis. If it is determined
that the condition is caused by the type of fuel used,
repairs might not be covered by the vehicle warranty.
5-6

Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that help prevent
engine and fuel system deposits from forming, allowing
the emission control system to work properly. In most
cases, you should not have to add anything to the fuel.
However, some gasolines contain only the minimum
amount of additive required to meet U.S. Environmental
Protection Agency regulations. To help keep fuel injectors
and intake valves clean, or if the vehicle experiences
problems due to dirty injectors or valves, look for gasoline
that is advertised as TOP TIER Detergent Gasoline.
For customers who do not use TOP TIER Detergent
Gasoline regularly, one bottle of GM Fuel System
Treatment PLUS, added to the fuel tank at every engine
oil change, can help clean deposits from fuel injectors
and intake valves. GM Fuel System Treatment PLUS is
the only gasoline additive recommended by General
Motors.
Also, your dealer/retailer has additives that will help
correct and prevent most deposit-related problems.
Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines might be available in
your area. We recommend that you use these gasolines,
if they comply with the specications described earlier.
However, E85 (85% ethanol) and other fuels containing
more than 10% ethanol must not be used in vehicles that
were not designed for those fuels.Notice:This vehicle was not designed for fuel
that contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in the fuel
system and also damage plastic and rubber parts.
That damage would not be covered under the vehicle
warranty.
Some gasolines that are not reformulated for low
emissions can contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. We recommend against
the use of such gasolines. Fuels containing MMT can
reduce the life of spark plugs and the performance
of the emission control system could be affected.
The malfunction indicator lamp might turn on. If this
occurs, return to your dealer/retailer for service.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel might be hard
to nd. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel. Costly
repairs caused by use of improper fuel would not
be covered by the vehicle warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business in
the country where you will be driving.
5-7

Using the Maintenance Schedule
We want to help keep this vehicle in good working
condition. But we do not know exactly how you will drive
it. You might drive very short distances only a few times a
week. Or you might drive long distances all the time in
very hot, dusty weather. You might use the vehicle in
making deliveries. Or you might drive it to work, to do
errands, or in many other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You might need more
frequent checks and replacements. So please read the
following and note how you drive. If you have any
questions on how to keep the vehicle in good condition,
see your dealer/retailer.
This schedule is for vehicles that:
carry passengers and cargo within recommended
limits on the Tire and Loading Information label.
SeeLoading the Vehicle on page 4-24.
are driven on reasonable road surfaces within legal
driving limits.
use the recommended fuel. SeeGasoline Octane
on page 5-5.
The services inScheduled Maintenance on page 6-4
should be performed when indicated. SeeAdditional
Required Services on page 6-6andMaintenance
Footnotes on page 6-8for further information.
{CAUTION:
Performing maintenance work on a vehicle can be
dangerous. In trying to do some jobs, you can be
seriously injured. Do your own maintenance work
only if you have the required know-how and the
proper tools and equipment for the job. If you have
any doubt, see your dealer/retailer to have a
qualied technician do the work. SeeDoing Your
Own Service Work on page 5-4.
Some maintenance services can be complex. So, unless
you are technically qualied and have the necessary
equipment, have your dealer/retailer do these jobs.
When you go to your dealer/retailer for service, trained
and supported service technicians will perform the
work using genuine parts.
To purchase service information, seeService
Publications Ordering Information on page 7-15.
Owner Checks and Services on page 6-10tells what
should be checked, when to check it, and what can easily
be done to help keep the vehicle in good condition.
6-3

Electrical System (cont.)
Windshield Wiper Fuses.............................5-113
Engine
Air Cleaner/Filter.........................................5-23
Check and Service Engine Soon Lamp...........3-66
Coolant......................................................5-27
Coolant Heater............................................2-29
Coolant Temperature Gage...........................3-65
Coolant Temperature Warning Light................3-64
Drive Belt Routing.......................................6-16
Engine Compartment Overview......................5-12
Exhaust.....................................................2-36
Oil .............................................................5-18
Oil Life System...........................................5-21
Overheated Protection Operating Mode...........5-36
Overheating................................................5-34
Starting......................................................2-27
Enhanced StabiliTrak
®....................................... 4-6
Entry Lighting.................................................3-41
Event Data Recorders.....................................7-17
Extender, Safety Belt.......................................1-27
Exterior Lighting Battery Saver..........................3-40
F
Filter
Engine Air Cleaner......................................5-23
Finish Damage.............................................5-111
Flashers, Hazard Warning.................................. 3-6Flash-to-Pass.................................................3-13
Flat Tire........................................................5-84
Flat Tire, Changing.........................................5-94
Flat Tire, Storing...........................................5-102
Fluid
Automatic Transmission................................5-25
Power Steering...........................................5-37
Windshield Washer......................................5-38
Fog Lamp
Fog ...........................................................3-38
Fog Lamp Light..............................................3-70
Forward Collision Alert (FAC) System.................. 3-9
Front Axle......................................................5-49
Fuel............................................................... 5-5
Additives...................................................... 5-7
California Fuel.............................................. 5-6
Filling a Portable Fuel Container....................5-10
Filling the Tank............................................. 5-8
Fuels in Foreign Countries.............................. 5-7
Gage .........................................................3-71
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-6
Fuses
Fuses and Circuit Breakers.........................5-113
Rear Underseat Fuse Block.........................5-118
Underhood Fuse Block...............................5-114
Windshield Wiper.......................................5-113
5

G
Gage
Engine Coolant Temperature.........................3-65
Fuel..........................................................3-71
Speedometer..............................................3-57
Tachometer.................................................3-57
Garage Door Opener.......................................2-53
Gasoline
Octane........................................................ 5-5
Specications............................................... 5-6
Glove Box.....................................................2-60
GM Mobility Reimbursement Program.................. 7-7
H
Hazard Warning Flashers................................... 3-6
Head Restraints............................................... 1-5
Headlamp
Aiming .......................................................5-50
Headlamp Wiring...........................................5-113
Headlamps....................................................3-32
Bulb Replacement.......................................5-51
Daytime Running Lamp................................3-36
Flash-to-Pass..............................................3-13
Halogen Bulbs............................................5-51
High Intensity Discharge (HID) Lighting...........5-51
High/Low Beam Changer................................ 3-9Headlamps (cont.)
On Reminder..............................................3-36
Washer......................................................3-16
Wiper Activated...........................................3-36
Head-Up Display (HUD)...................................3-43
Heated Seats................................................... 1-3
Heated Steering Wheel..................................... 3-7
Heater...........................................................3-48
Engine Coolant...........................................2-29
Highbeam On Light.........................................3-70
High-Speed Operation, Tires.............................5-65
Highway Hypnosis...........................................4-19
Hill and Mountain Roads..................................4-20
Hood
Checking Things Under................................5-10
Release.....................................................5-11
Horn ............................................................... 3-6
How to Wear Safety Belts Properly...................1-12
I
Ignition Positions.............................................2-26
Immobilizer....................................................2-24
Immobilizer Operation......................................2-24
Inadvertent Power Battery Saver.......................3-42
Infants and Young Children, Restraints...............1-31
Ination - Tire Pressure...................................5-64
Inator Kit, Tire...............................................5-87
6