2008 BUICK LACROSSE engine control

If your vehicle has the 5.3L V8 engine (VIN Code C),
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 your 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.
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 5-7for
additional information.
California Fuel
If your 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, your 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 your
vehicle might fail a smog-check test. SeeMalfunction
Indicator Lamp on page 3-42. 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 your 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 your vehicle experiences
problems due to dirty injectors or valves, look for gasoline
that is advertised as TOP TIER Detergent Gasoline. 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:Your 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 your
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 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

If Steam Is Coming From Your Engine
{CAUTION:
Steam from an overheated engine can burn
you badly, even if you just open the hood. Stay
away from the engine if you see or hear steam
coming from it. Turn it off and get everyone
away from the vehicle until it cools down. Wait
until there is no sign of steam or coolant before
you open the hood.
If you keep driving when the vehicles engine is
overheated, the liquids in it can catch re. You
or others could be badly burned. Stop your
engine if it overheats, and get out of the vehicle
until the engine is cool.
SeeOverheated Engine Protection Operating
Mode on page 5-32for information on driving to
a safe place in an emergency.Notice:If your engine catches re because you
keep driving with no coolant, your vehicle can be
badly damaged. The costly repairs would not be
covered by your warranty. SeeOverheated Engine
Protection Operating Mode on page 5-32for
information on driving to a safe place in an
emergency.
If No Steam Is Coming From Your
Engine
If you get an engine overheat warning, but see or hear
no steam, the problem may not be too serious.
Sometimes the engine can get a little too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in NEUTRAL (N)
while stopped. If it is safe to do so, pull off the road,
shift to PARK (P) or NEUTRAL (N) and let the
engine idle.
2. Set the climate controls to the highest heat setting
and fan speed and open the windows as necessary.
5-31

CAUTION: (Continued)
Battery uid contains acid that can burn you.
Do not get it on you. If you accidentally get it
in your eyes or on your skin, ush the place
with water and get medical help immediately.
5. Check that the jumper cables do not have loose or
missing insulation. If they do, you could get a
shock. The vehicles could be damaged too.
Before you connect the cables, here are some
basic things you should know. Positive (+) will go to
positive (+) or to a remote positive (+) terminal if
the vehicle has one. Negative will go to a heavy,
unpainted metal engine part or to a remote
negative (−) terminal if the vehicle has one.
Notice:If you connect a negative cable to the
Engine Control Module (ECM), ECM mounting
bracket or any cables that attach to the ECM
bracket, you may damage the ECM. Attach the
negative cable to a heavy, unpainted metal engine
part, other than the ECM, ECM bracket or cables
attached to the ECM bracket.Do not connect positive (+) to negative (−), or you
will get a short that would damage the battery
and maybe other parts too. And do not connect the
negative (−) cable to the negative (−) terminal on
the dead battery because this can cause sparks.
3.8L V6 Engine shown, 3.6L V6 Engine similar
5-53

Underhood Fuse Block
Some fuses and relays are located in the underhood fuse
block on the passenger side of the vehicle in the engine
compartment. SeeEngine Compartment Overview on
page 5-12for more information on location.
Notice:Spilling liquid on any electrical components
on your vehicle may damage it. Always keep the
covers on any electrical component.
Mini-Fuses Usage
1 Driver Side High-Beam
2 Passenger Side High-Beam
Mini-Fuses Usage
3 Driver Side Low-Beam
4 Passenger Side Low-Beam
5 Windshield Wiper
6 Washer/Regulated Voltage Control
7 Fog Lamps
8 Transmission Control Module
9 Supplemental Inatable Restraint
10 Auxiliary Power
11 Horn
12 Emission
13 Air Conditioner Clutch
14 Oxygen Sensor
15 Powertrain Control Module
16Powertrain Control Module,
Electronic Throttle Control
17 Electronic Throttle Control
18 Display
19 Antilock Brake Solenoid
20 Fuel Injector
21 Transmission Solenoid 3.6L & 3.8L V6 Engines
5-112

Fuses Usage
HVAC Climate Control System
FUEL/PUMP Fuel Pump
AIRBAG/
DISPLAYAirbag, Display
COMPASS Compass
ABS Antilock Brake System
Fuses Usage
ETC/ECMElectronic Throttle Control, Engine
Control Module
A/C CMPRSR Air Conditioning Compressor
INJ 1 Injectors 1
ECM/TCMEngine Control Module,
Transmission Control Module
TRANS Transmission
EMISSIONS1 Emissions 1
ABS SOL Antilock Brake Solenoid
ECM IGN Engine Control Module, Ignition
INJ 2 Injectors 2
EMISSIONS2 Emissions 2
WPR Windshield Wipers
AUX PWR Auxiliary Power
WSW/RVCWindshield Washer, Regulated
Voltage Control
LT LO BEAM Driver Side Low-Beam Headlamp
RT LO BEAMPassenger Side Low-Beam
Headlamp
FOG LAMPS Fog Lamps
LT HI BEAM Driver Side High-Beam Headlamp 5.3L V8 Engine
5-114

Scheduled Maintenance
Service MaintenanceIMaintenanceII
Change engine oil and lter. SeeEngine Oil on page 5-18. Reset oil life system.
SeeEngine Oil Life System on page 5-21.An Emission Control Service.••
Visually check for any leaks or damage.See footnote (k).••
Inspect engine air cleaner lter. If necessary, replace lter. SeeEngine Air
Cleaner/Filter on page 5-23.See footnote (l).•
Rotate tires and check ination pressures and wear. SeeTire Inspection and
Rotation on page 5-75and “Tire Wear Inspection” inAt Least Once a Month
on page 6-9.••
Inspect brake system.See footnote (a).••
Check engine coolant and windshield washer uid levels and add uid as
needed.••
Perform any needed additional services. See “Additional Required Services” in
this section.••
Inspect suspension and steering components.See footnote (b).•
Inspect engine cooling system.See footnote (c).•
Inspect wiper blades.See footnote (d).•
Inspect restraint system components.See footnote (e).•
Lubricate body components.See footnote (f).•
Check transmission uid level and add uid as needed.•
Replace passenger compartment air lter.See footnote (g).•
Inspect throttle system.See footnote (j).•
6-5

Additional Required Services
The following services should be performed at the rst maintenance service (IorII) after the indicated miles
(kilometers) shown for each item.
Additional Required Services
Service and Miles (Kilometers)25,000
(40 000)50,000
(80 000)75,000
(120 000)100,000
(160 000)125,000
(200 000)150,000
(240 000)
Inspect fuel system for damage or leaks.• •••••
Inspect exhaust system for loose or
damaged components.• •••••
Replace engine air cleaner lter. See
Engine Air Cleaner/Filter on page 5-23.•••
Change automatic transmission uid and
lter (severe service).See
footnote (h).•••
Change automatic transmission uid and
lter (normal service).•
Replace spark plugs and inspect spark
plug wires.An Emission Control Service.•
Engine cooling system service (or every
ve years, whichever occurs rst).An
Emission Control Service. See
footnote (i).•
Inspect engine accessory drive belt.An
Emission Control Service. See
footnote (m).•
6-6