Page 286 of 371

6-4
Be sure the posted octane for regular is at least 87
(at least 91 for premium). If the octane is less than 87,
you may get a heavy knocking noise when you drive.
If it's bad enough, it can damage your engine.
If you're using fuel rated at the recommended octane or
higher and you hear heavy knocking, your engine needs
service. But don't worry if you hear a little pinging
noise when you're accelerating or driving up a hill.
That's normal, and you don't have to buy a higher
octane fuel to get rid of pinging. It's the heavy,
constant knock that means you have a problem.
If your vehicle is certified to meet California Emission
Standards (indicated on the underhood emission control
label), it is designed to operate on fuels that meet
California specifications. If such fuels are not available
in states adopting California emissions standards,
your vehicle will operate satisfactorily on fuels meeting
federal specifications, but emission control system
performance may be affected. The malfunction indicator lamp on your instrument
panel may turn on and/or your vehicle may fail a
smog
-check test. See ªMalfunction Indicator Lampº
in the Index. If this occurs, return to your authorized
Cadillac dealer for diagnosis to determine the cause of
failure. In the event it is determined that the cause of the
condition is the type of fuels used, repairs may not be
covered by your warranty.
Some gasolines that are not reformulated for low
emissions may contain an octane
-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask your service station operator whether or
not the fuel contains MMT. General Motors does not
recommend the use of such gasolines. If fuels containing
MMT are used, spark plug life may be reduced and your
emission control system performance may be affected.
The malfunction indicator lamp on your instrument
panel may turn on. If this occurs, return to your
authorized Cadillac dealer for service.
Page 290 of 371

6-8
CAUTION:
If you get gasoline on yourself and then
something ignites it, you could be badly burned.
Gasoline can spray out on you if you open the
fuel filler cap too quickly. This spray can happen
if your tank is nearly full, and is more likely in
hot weather. Open the fuel filler cap slowly and
wait for any ªhissº noise to stop. Then unscrew
the cap all the way.
Be careful not to spill gasoline. Clean gasoline from
painted surfaces as soon as possible. See ªCleaning the
Outside of Your Vehicleº in the Index.When you put the cap back on, turn it to the right
(clockwise) until you hear a clicking sound. Make sure
you fully install the cap. The diagnostic system can
determine if the fuel cap has been left off or improperly
installed. This would allow fuel to evaporate into the
atmosphere. See ªMalfunction Indicator Lampº in
the Index.
The CHECK GAS CAP message in the Driver
Information Center will come on if the fuel cap is
not properly reinstalled.
NOTICE:
If you need a new cap, be sure to get the right
type. Your dealer can get one for you. If you get
the wrong type, it may not fit properly. This may
cause your malfunction indicator lamp to light
and your fuel tank and emissions system may be
damaged. See ªMalfunction Indicator Lampº in
the Index.
Page 318 of 371
6-36
Bulb Replacement
For the proper type of replacement bulb, see
ªReplacement Bulbsº in the Index.
For any bulb changing procedure not listed in this
section, contact your dealer service department.
High Intensity Discharge (HID) Lighting
(If Equipped)
CAUTION:
The low beam High Intensity Discharge lighting
system operates at a very high voltage. If you try
to service any of the system components, you
could be seriously injured. Have your dealer or
a qualified technician service them.
Halogen Bulbs
CAUTION:
Halogen bulbs have pressurized gas inside
and can burst if you drop or scratch the bulb.
You or others could be injured. Be sure to read
and follow the instructions on the bulb package.