2005 CADILLAC DEVILLE octane

If the Light Is On Steady
You 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 5-7.
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.
SeeGasoline 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.
Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have or
may begin programs to inspect the emission control
equipment on your vehicle. Failure to pass this
inspection could prevent you from getting a vehicle
registration.
Here are some things you need to know in order to help
your vehicle pass an inspection:
Your vehicle will not pass this inspection if the SERVICE
ENGINE SOON or CHECK ENGINE light is on or not
working properly.
Your vehicle will not pass this inspection if the OBD
(on-board diagnostic) system determines that critical
emission control systems have not been completely
diagnosed by the system. The vehicle would be
considered not ready for inspection.
3-52

Service............................................................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of Your
Vehicle......................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling the Tank..............................................5-7
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...................................................5-14
Engine Oil Life System..................................5-17
Engine Air Cleaner/Filter................................5-19
Automatic Transaxle Fluid..............................5-21
Engine Coolant.............................................5-24
Coolant Surge Tank Pressure Cap..................5-27
Engine Overheating.......................................5-27
Overheated Engine Protection
Operating Mode........................................5-29
Cooling System............................................5-30
Power Steering Fluid.....................................5-35Windshield Washer Fluid................................5-36
Brakes........................................................5-37
Battery........................................................5-40
Jump Starting...............................................5-42
Headlamp Aiming...........................................5-48
Headlamp Horizontal Aiming...........................5-49
Headlamp Vertical Aiming..............................5-50
Bulb Replacement..........................................5-51
Halogen Bulbs..............................................5-51
Headlamps..................................................5-51
Front Turn Signal, Sidemarker, Parking and
Cornering Lamps.......................................5-55
Replacement Bulbs.......................................5-56
Windshield Wiper Blade Replacement..............5-56
Tires..............................................................5-57
Tire Sidewall Labelling...................................5-58
Tire Terminology and Denitions.....................5-62
Ination - Tire Pressure.................................5-65
Tire Pressure Monitor Operation.....................5-68
Tire Inspection and Rotation...........................5-69
When It Is Time for New Tires.......................5-70
Buying New Tires.........................................5-71
Uniform Tire Quality Grading..........................5-72
Wheel Alignment and Tire Balance..................5-73
Wheel Replacement......................................5-73
Tire Chains..................................................5-75
Section 5 Service and Appearance Care
5-1

Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your vehicle can
affect the airow around it. This may cause wind
noise and affect windshield washer performance.
Check with your dealer before adding equipment to the
outside of your vehicle.
Fuel
Use of the recommended fuel is an important part of the
proper maintenance of your vehicle.
Gasoline Octane
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.
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.
California Fuel
If your vehicle is certied to meet California Emission
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, your
vehicle will operate satisfactorily on fuels meeting
federal specications, but emission control system
performance may be affected. The malfunction indicator
lamp may turn on and your vehicle may fail a
smog-check test. SeeMalfunction Indicator Lamp on
page 3-50. If this occurs, return to your authorized
GM dealer for diagnosis. If it is determined that
the condition is caused by the type of fuel used,
repairs may not be covered by your warranty.
5-5

Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent engine and fuel system deposits from forming,
allowing your emission control system to work properly.
In most cases, you should not have to add anything to
your fuel. However, some gasolines contain only the
minimum amount of additive required to meet U.S.
Environmental Protection Agency regulations. General
Motors recommends that you buy gasolines that are
advertised to help keep fuel injectors and intake valves
clean. If your vehicle experiences problems due to dirty
injectors or valves, try a different brand of gasoline.
Also, your GM dealer has additives that will help correct
and prevent most deposit-related problems.
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.
5-6

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 6-13. 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

Electrical System (cont.)
Headlamp Wiring.........................................5-97
Power Windows and Other Power Options.........5-97
Rear Underseat Fuse Block.........................5-101
Underhood Fuse Block.................................5-98
Windshield Wiper Fuses...............................5-97
Engine
Air Cleaner/Filter.........................................5-19
Battery.......................................................5-40
Check and Service Engine Soon Light............3-50
Coolant......................................................5-24
Coolant Heater............................................2-27
Coolant Temperature Gage...........................3-49
Coolant Temperature Warning Light................3-49
Engine Compartment Overview......................5-12
Exhaust.....................................................2-35
Oil .............................................................5-14
Oil Life System...........................................5-17
Overheated Protection Operating Mode...........5-29
Overheating................................................5-27
Speed Limiter.............................................3-44
Starting......................................................2-26
Entry Lighting.................................................3-21
Event Data Recorders (EDR)............................. 7-9
Extender, Safety Belt.......................................1-27
Exterior Lamps...............................................3-15
Exterior Lighting Battery Saver..........................3-20F
Filter
Engine Air Cleaner......................................5-19
Finish Damage...............................................5-94
Flash-to-Pass................................................... 3-9
Flat Tire........................................................5-76
Flat Tire, Changing.........................................5-77
Flat Tire, Storing.............................................5-85
Fluid
Automatic Transaxle.....................................5-21
Power Steering...........................................5-35
Windshield Washer......................................5-36
Fog Lamp Light..............................................3-54
Fog Lamps....................................................3-18
Front Storage Area.........................................2-49
Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-5
Data Display...............................................3-56
Filling a Portable Fuel Container....................5-10
Filling Your Tank........................................... 5-7
Fuels in Foreign Countries.............................. 5-6
Gage.........................................................3-55
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-5
Full Floor Console Storage Area.......................2-49
5

Fuses
Fuses and Circuit Breakers...........................5-98
Rear Underseat Fuse Block.........................5-101
Underhood Fuse Block.................................5-98
Windshield Wiper.........................................5-97
G
Gage
Engine Coolant Temperature.........................3-49
Fuel..........................................................3-55
Speedometer..............................................3-43
Tachometer.................................................3-44
Garage Door Opener.......................................2-44
Gasoline
Octane........................................................ 5-5
Specications............................................... 5-5
Glove Box.....................................................2-49
Glovebox-Mounted CD Changer......................3-100
GM Mobility Reimbursement Program.................. 7-5
H
Hazard Warning Flashers................................... 3-6
Headlamp
Aiming.......................................................5-48
Horizontal Aiming.........................................5-49
Vertical Aiming............................................5-50Headlamp Wiring............................................5-97
Headlamps....................................................5-51
Bulb Replacement.......................................5-51
Daytime Running Lamps...............................3-16
Flash-to-Pass............................................... 3-9
Front Turn Signal, Sidemarker,
Parking and Cornering Lamps....................5-55
Halogen Bulbs............................................5-51
High/Low Beam Changer................................ 3-9
On Reminder..............................................3-16
Wiper Activated...........................................3-16
Heated Seats................................................... 1-3
Heated Steering Wheel..................................... 3-7
Heater...........................................................3-30
Highbeam On Light.........................................3-54
Highway Hypnosis...........................................4-23
Hill and Mountain Roads..................................4-23
HomeLink
®Wireless Control System.................2-44
HomeLink®Wireless Control System
Operation...................................................2-45
Hood
Checking Things Under................................5-10
Release.....................................................5-11
Horn............................................................... 3-6
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-12
6