2005 CADILLAC STS octane

If the Light Is Flashing
The following may prevent more serious damage to
your vehicle:
Reducing vehicle speed
Avoiding hard accelerations
Avoiding 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 your 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 for service as soon as possible.
If the Light Is On Steady
You also may 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 5-8. The
diagnostic system can determine if the fuel cap has
been left off or improperly installed. A loose or missing
fuel cap will allow 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 electrical system may be wet. The condition
will usually be 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 will
cause your engine not to run as efficiently as designed.
You may 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 may 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 can check the vehicle. Your dealer has
the proper test equipment and diagnostic tools to x
any mechanical or electrical problems that may
have developed.
3-69

Service............................................................5-3
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....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
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...................................................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter................................5-20
Automatic Transmission Fluid.........................5-21
Engine Coolant.............................................5-22
Coolant Surge Tank Pressure Cap..................5-24
Engine Overheating.......................................5-24
Overheated Engine Protection
Operating Mode........................................5-26
Cooling System............................................5-27Power Steering Fluid.....................................5-31
Windshield Washer Fluid................................5-32
Brakes........................................................5-34
Battery........................................................5-37
Jump Starting...............................................5-38
All-Wheel Drive..............................................5-42
Rear Axle.......................................................5-44
Front Axle......................................................5-45
Headlamp Aiming...........................................5-46
Bulb Replacement..........................................5-48
High Intensity Discharge (HID) Lighting............5-48
Halogen Bulbs..............................................5-49
Front Turn Signal Lamps...............................5-49
Sidemarker Lamps........................................5-50
Back-Up Lamps............................................5-50
Replacement Bulbs.......................................5-51
Windshield Replacement.................................5-51
Windshield Wiper Blade Replacement..............5-51
Tires..............................................................5-53
Tire Sidewall Labelling...................................5-54
Tire Terminology and Denitions.....................5-58
Ination - Tire Pressure.................................5-60
Tire Pressure Monitor System.........................5-62
Section 5 Service and Appearance Care
5-1

Fuel
Use of the recommended fuel is an important part of the
proper maintenance of your vehicle.
Gasoline Octane
If your vehicle has the 3.6L V6 engine, use regular
unleaded gasoline with a posted octane of 87 or higher.
However, for best performance and for trailer towing,
you may wish to use middle grade or premium unleaded
gasoline. If the octane is less than 87, you may get 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 might damage your engine.
If your vehicle has the 4.6L V8 engine, use premium
unleaded gasoline with a posted octane of 91 or higher
for best performance. You may also use middle
grade or regular unleaded gasoline rated at 87 octane
or higher, but your vehicle’s acceleration may be slightly
reduced. If the octane is less than 87, you may get 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 might damage your engine.
Gasoline Specications
It is recommended that gasoline meet specications
which were developed by automobile manufacturers
around the world and contained in the World-Wide Fuel
Charter which is available from the Alliance of Automobile
Manufacturers at www.autoalliance.org/fuel_charter.htm.
Gasoline meeting these specications could provide
improved driveability and emission control system
performance compared to other gasoline.
5-5

Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines may be available in
your area to contribute to clean air. General Motors
recommends that you use these gasolines, particularly if
they comply with the specications described earlier.
Notice:Your vehicle was not designed for fuel that
contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the plastic and rubber
parts. That damage would not be covered under
your warranty.
Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT); ask the attendant where you
buy gasoline whether the fuel contains MMT. General
Motors does not recommend the use of such gasolines.Fuels containing MMT can reduce the life of spark plugs
and the performance of the emission control system
may be affected. The malfunction indicator lamp
may turn on. If this occurs, return to your authorized GM
dealer for service.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may 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 your 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

This schedule is for vehicles that:
carry passengers and cargo within recommended
limits. You will nd these limits on the tire and
loading information label. SeeLoading Your Vehicle
on page 4-30.
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 6-7for 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 GM Goodwrench
®dealer to have a
qualied technician do the work.Some maintenance services can be complex. So,
unless you are technically qualied and have the
necessary equipment, you should have your GM
Goodwrench
®dealer do these jobs.
When you go to your GM Goodwrench
®dealer for your
service needs, you will know that GM-trained and
supported service technicians will perform the work
using genuine GM parts.
If you want to purchase service information, seeService
Publications Ordering Information on page 7-11.
Owner Checks and Services on page 6-9tells you what
should be checked, when to check it and what you
can easily do to help keep your vehicle in good
condition.
The proper replacement parts, uids and lubricants to
use are listed inRecommended Fluids and Lubricants
on page 6-12andNormal Maintenance Replacement
Parts on page 6-14. When your vehicle is serviced,
make sure these are used. All parts should be replaced
and all necessary repairs done before you or anyone
else drives the vehicle. We recommend the use of
genuine GM parts.
6-3

Engine (cont.)
Coolant Temperature Gage...........................3-67
Coolant Temperature Warning Light................3-67
Engine Compartment Overview......................5-12
Exhaust.....................................................2-33
Oil .............................................................5-15
Oil Life System...........................................5-18
Overheated Protection Operating Mode...........5-26
Overheating................................................5-24
Starting......................................................2-24
Entry Lighting.................................................3-42
Event Data Recorders (EDR)............................. 7-8
Extender, Safety Belt.......................................1-26
Exterior Lighting Battery Saver..........................3-41
F
Filter
Engine Air Cleaner......................................5-20
Finish Damage...............................................5-92
Flash-to-Pass.................................................3-13
Flat Tire........................................................5-74
Flat Tire, Changing.........................................5-74
Flat Tire, Storing.............................................5-83
Fluid
Automatic Transmission................................5-21
Power Steering...........................................5-31
Windshield Washer......................................5-32
Fog Lamp Light..............................................3-71Fog Lamps....................................................3-39
Forward Collision Alert (FAC) System.................. 3-9
Front Axle......................................................5-45
Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-6
Filling a Portable Fuel Container....................5-10
Filling Your Tank........................................... 5-8
Fuels in Foreign Countries.............................. 5-7
Gage.........................................................3-72
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-5
Fuses
Fuses and Circuit Breakers...........................5-95
Rear Underseat Fuse Block..........................5-99
Underhood Fuse Block.................................5-96
Windshield Wiper.........................................5-95
G
Gage
Engine Coolant Temperature.........................3-67
Fuel..........................................................3-72
Speedometer..............................................3-62
Tachometer.................................................3-62
Garage Door Opener.......................................2-41
Gasoline
Octane........................................................ 5-5
Specications............................................... 5-5
5