2005 BUICK LACROSSE octane

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.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 to help your
vehicle pass an inspection:
Your vehicle will not pass this inspection if the 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. This can happen if
you have recently replaced your battery or if your
battery has run down. The diagnostic system is
designed to evaluate critical emission control systems
during normal driving. This may take several days
of routine driving. If you have done this and your vehicle
still does not pass the inspection for lack of OBD
system readiness, your GM dealer can prepare the
vehicle for inspection.
3-41

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....................................5-6
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................................5-19
Automatic Transmission Fluid.........................5-21
Engine Coolant.............................................5-21
Radiator Pressure Cap..................................5-24
Engine Overheating.......................................5-24
Overheated Engine Protection
Operating Mode........................................5-26
Cooling System............................................5-26Power Steering Fluid.....................................5-33
Windshield Washer Fluid................................5-34
Brakes........................................................5-35
Battery........................................................5-38
Jump Starting...............................................5-39
Headlamp Aiming...........................................5-43
Bulb Replacement..........................................5-45
Halogen Bulbs..............................................5-45
Headlamps and Sidemarker Lamps.................5-46
Front Turn Signal and Parking Lamps..............5-47
Fog Lamps..................................................5-48
Taillamps, Turn Signal, Sidemarker,
Stoplamps and Back-up Lamps...................5-48
Windshield Wiper Blade Replacement..............5-51
Tires..............................................................5-52
Tire Sidewall Labelling...................................5-53
Tire Terminology and Denitions.....................5-55
Ination - Tire Pressure.................................5-58
Tire Inspection and Rotation...........................5-60
When It Is Time for New Tires.......................5-61
Buying New Tires.........................................5-62
Uniform Tire Quality Grading..........................5-63
Wheel Alignment and Tire Balance..................5-64
Wheel Replacement......................................5-65
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
The 8th digit of your vehicle identication number (VIN)
shows the code letter or number that identies your
engine. You will nd the VIN at the top left of the
instrument panel. SeeVehicle Identication Number
(VIN) on page 5-86.
Gasoline Octane
If your vehicle has the 3800 V6 engine, use regular
unleaded gasoline with a posted octane of 87 or higher.
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. A
little pinging noise when you accelerate or drive
uphill is considered normal. This does not indicate a
problem exists or that a higher-octane fuel is necessary.
If you are using 87 octane or higher-octane fuel and
hear heavy knocking, your engine needs service.
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.
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

Using the Maintenance Schedule
We at General Motors want to help you keep your
vehicle in good working condition. But we do not know
exactly how you will drive it. You may drive very
short distances only a few times a week. Or you may
drive long distances all the time in very hot, dusty
weather. You may use your vehicle in making deliveries.
Or you may 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 may 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 your vehicle in good condition,
see your GM Goodwrench
®dealer.
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 4-29.
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 6-8tells you what
should be checked, when to check it and what you
can easily do to help keep your vehicle in good
condition.
6-3

Electrical System (cont.)
Power Windows and Other Power Options......5-88
Underhood Fuse Block.................................5-90
Windshield Wiper Fuses...............................5-87
Engine
Air Cleaner/Filter.........................................5-19
Battery.......................................................5-38
Change Engine Oil Light...............................3-43
Check and Service Engine Soon Light............3-39
Coolant......................................................5-21
Coolant Heater............................................2-23
Coolant Temperature Gage...........................3-38
Coolant Temperature Warning Light................3-38
Engine Compartment Overview......................5-12
Exhaust.....................................................2-30
Oil .............................................................5-15
Oil Life System...........................................5-18
Overheated Protection Operating Mode...........5-26
Overheating................................................5-24
Reduced Power Light...................................3-44
Starting......................................................2-22
Entry Lighting.................................................3-16
Event Data Recorders (EDR)............................. 7-9
Extender, Safety Belt.......................................1-30
Exterior Lamps...............................................3-13
Exterior Lighting Battery Saver..........................3-15F
Filter
Engine Air Cleaner......................................5-19
Finish Damage...............................................5-84
Flash-to-Pass................................................... 3-8
Flat Tire........................................................5-67
Flat Tire, Changing.........................................5-68
Flat Tire, Storing.............................................5-76
Fluid
Automatic Transmission................................5-21
Power Steering...........................................5-33
Windshield Washer......................................5-34
Fog Lamps............................................3-15, 5-48
Folding Rear Seat............................................ 1-8
Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-6
Check Gas Cap Light...................................3-46
Filling a Portable Fuel Container....................5-10
Filling Your Tank........................................... 5-8
Fuels in Foreign Countries.............................. 5-7
Gage.........................................................3-46
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-6
Low Warning Light.......................................3-46
5

Fuses
Fuses and Circuit Breakers...........................5-88
Instrument Panel Fuse Block.........................5-88
Underhood Fuse Block.................................5-90
Windshield Wiper.........................................5-87
G
Gage
Engine Coolant Temperature.........................3-38
Fuel..........................................................3-46
Speedometer..............................................3-32
Tachometer.................................................3-32
Garage Door Opener.......................................2-36
Gasoline
Octane........................................................ 5-5
Specications............................................... 5-6
Glove Box.....................................................2-40
GM Mobility Reimbursement Program.................. 7-5
H
Hazard Warning Flashers................................... 3-6
Head Restraints............................................... 1-7
Headlamp
Aiming.......................................................5-43Headlamp Wiring............................................5-87
Headlamps
Bulb Replacement.......................................5-45
Daytime Running Lamps/Automatic
Headlamp System....................................3-14
Flash-to-Pass............................................... 3-8
Front Turn Signal and Parking Lamps.............5-47
Halogen Bulbs............................................5-45
Headlamps and Sidemarker Lamps................5-46
High/Low Beam Changer................................ 3-8
Suggested Light..........................................3-44
Headlamps and Sidemarker Lamps...................5-46
Heated Seats................................................... 1-5
Heater...........................................................3-21
Heater...........................................................3-24
Highbeam On Light.........................................3-44
Highway Hypnosis...........................................4-21
Hill and Mountain Roads..................................4-22
HomeLink
®Transmitter....................................2-36
HomeLink®Transmitter, Programming................2-36
Hood
Checking Things Under................................5-10
Release.....................................................5-11
Horn............................................................... 3-6
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-15
6