2008 CADILLAC XLR octane

If the Light Is Flashing
The following can prevent more serious damage to
your vehicle:
Reduce vehicle speed.
Avoid hard accelerations.
Avoid 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 the 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/retailer
for service as soon as possible.
If the Light Is On Steady
You might 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 6-7. The diagnostic
system can determine if the fuel cap has been left off orimproperly 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.
Did you just drive through a deep puddle of water?
If so, your 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.
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 6-5. Poor fuel quality causes
the engine not to run as efficiently as designed. You
might 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 might 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/retailer can check the vehicle. Your
dealer/retailer has the proper test equipment and
diagnostic tools to x any mechanical or electrical
problems that might have developed.
3-55

Service............................................................6-3
Accessories and Modications..........................6-3
California Proposition 65 Warning.....................6-3
California Perchlorate Materials Requirements......6-4
Doing Your Own Service Work.........................6-4
Adding Equipment to the Outside of
Your Vehicle..............................................6-4
Fuel................................................................6-5
Gasoline Octane............................................6-5
Gasoline Specications....................................6-5
California Fuel...............................................6-6
Additives.......................................................6-6
Fuels in Foreign Countries...............................6-7
Filling the Tank..............................................6-7
Filling a Portable Fuel Container.....................6-10
Checking Things Under the Hood....................6-10
Hood Release..............................................6-11
Engine Compartment Overview.......................6-12
Engine Oil...................................................6-16
Engine Oil Life System..................................6-20
Engine Air Cleaner/Filter................................6-22
Automatic Transmission Fluid.........................6-24
Engine Coolant.............................................6-24
Coolant Surge Tank Pressure Cap..................6-27Engine Overheating.......................................6-27
Overheated Engine Protection
Operating Mode........................................6-29
Cooling System............................................6-30
Power Steering Fluid.....................................6-35
Windshield Washer Fluid................................6-36
Brakes........................................................6-37
Battery........................................................6-40
Jump Starting...............................................6-41
Rear Axle.......................................................6-46
Headlamp Aiming...........................................6-47
Headlamp Vertical Aiming..............................6-48
Bulb Replacement..........................................6-50
Windshield Replacement.................................6-50
Windshield Wiper Blade Replacement..............6-50
Tires..............................................................6-52
Winter Tires (XLR-V).....................................6-53
Tire Sidewall Labeling...................................6-54
Tire Terminology and Denitions.....................6-56
Run-Flat Tires..............................................6-58
Ination - Tire Pressure.................................6-60
Tire Pressure Monitor System.........................6-61
Tire Pressure Monitor Operation.....................6-63
Section 6 Service and Appearance Care
6-1

Fuel
Use of the recommended fuel is an important part of the
proper maintenance of your 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 your
vehicle’s engine. The VIN is at the top left of the
instrument panel. SeeVehicle Identification Number
(VIN) on page 6-89.
Gasoline Octane
If your 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
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.If your 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 6-6for additional information.
6-5

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 3-54. 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.
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.
6-6

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 5-22.
are driven on reasonable road surfaces within legal
driving limits.
use the recommended fuel. SeeGasoline Octane
on page 6-5.
The services inScheduled Maintenance on page 7-4
should be performed when indicated. SeeAdditional
Required Services on page 7-5andMaintenance
Footnotes on page 7-6for 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 6-4.Some maintenance services can be complex.
So, unless you are technically qualied and have
the necessary equipment, you should have your
dealer/retailer do these jobs.
When you go to your dealer/retailer for your service
needs, you will know that trained and supported service
technicians will perform the work using genuine parts.
If you want to purchase service information, seeService
Publications Ordering Information on page 8-16.
Owner Checks and Services on page 7-8tells 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 7-11andNormal Maintenance Replacement
Parts on page 7-13. 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 parts from your dealer/retailer.
7-3

Engine
Air Cleaner/Filter.........................................6-22
Check and Service Engine Soon Light............3-54
Coolant......................................................6-24
Coolant Temperature Gage...........................3-53
Drive Belt Routing.......................................7-14
Engine Compartment Overview......................6-12
Exhaust.....................................................2-34
Oil .............................................................6-16
Oil Life System...........................................6-20
Oil Pressure Gage.......................................3-57
Overheated Protection Operating Mode...........6-29
Overheating................................................6-27
Running While Parked..................................2-35
Starting......................................................2-24
Enter Destination............................................4-28
Entry/Exit Lighting...........................................3-32
Event Data Recorders.....................................8-18
Extender, Safety Belt.......................................1-23
Exterior Lamps...............................................3-28
Exterior Lighting Battery Saver..........................3-32F
Filter
Engine Air Cleaner......................................6-22
Finish Damage...............................................6-87
Flashers, Hazard Warning.................................. 3-6
Flash-to-Pass................................................... 3-9
Flat Tire........................................................6-78
Floor Mats.....................................................2-52
Fluid.............................................................6-24
Power Steering...........................................6-35
Windshield Washer......................................6-36
Fog Lamp
Fog ...........................................................3-30
Fog Lamp Light..............................................3-58
Fuel............................................................... 6-5
Additives...................................................... 6-6
California Fuel.............................................. 6-6
Filling a Portable Fuel Container....................6-10
Filling the Tank............................................. 6-7
Fuels in Foreign Countries.............................. 6-7
Gage.........................................................3-59
Gasoline Octane........................................... 6-5
Gasoline Specications.................................. 6-5
Fuses
Fuses and Circuit Breakers...........................6-90
Instrument Panel Fuse Block.........................6-90
Underhood Fuse Block.................................6-94
Windshield Wiper.........................................6-90
5

G
Gage
Engine Coolant Temperature.........................3-53
Engine Oil Pressure.....................................3-57
Fuel..........................................................3-59
Speedometer..............................................3-45
Tachometer.................................................3-45
Voltmeter Gage...........................................3-50
Garage Door Opener.......................................2-44
Gasoline
Octane........................................................ 6-5
Specications............................................... 6-5
Getting Started
Getting Started, Navigation............................. 4-4
Global Positioning System (GPS)......................4-50
Glove Box.....................................................2-52
GM Mobility Reimbursement Program.................. 8-7
H
Hazard Warning Flashers................................... 3-6
Headlamp
Aiming.......................................................6-47
Vertical Aiming............................................6-48Headlamps
Adaptive Forward Lighting System.................3-30
Bulb Replacement.......................................6-50
Daytime Running Lamps...............................3-29
Exterior Lamps............................................3-28
Flash-to-Pass............................................... 3-9
High/Low Beam Changer................................ 3-9
On Reminder..............................................3-29
Washer......................................................3-12
Wiper Activated...........................................3-29
Head-Up Display (HUD)...................................3-33
Heated Seats................................................... 1-3
Heated Steering Wheel..................................... 3-7
Heater...........................................................3-38
Highbeam On Light.........................................3-58
Highway Hypnosis...........................................5-16
Hill and Mountain Roads..................................5-16
Hood
Checking Things Under................................6-10
Release.....................................................6-11
Horn............................................................... 3-6
How to Wear Safety Belts Properly...................1-11
6