2008 CADILLAC XLR check engine light

Malfunction Indicator Lamp
Check Engine Light
A computer system called OBD II (On-Board
Diagnostics-Second Generation) monitors operation
of the fuel, ignition, and emission control systems.
It makes sure that emissions are at acceptable levels
for the life of the vehicle, helping to produce a cleaner
environment.
The check engine light
comes on to indicate
that there is an OBD II
problem and service
is required.
Malfunctions often are indicated by the system before
any problem is apparent. This can prevent more serious
damage to your vehicle. This system is also designed
to assist your service technician in correctly diagnosing
any malfunction.
Notice:If you keep driving your vehicle with
this light on, after a while, the emission controls
might not work as well, your vehicle’s fuel economymight not be as good, and the engine might not
run as smoothly. This could lead to costly repairs
that might not be covered by your warranty.
Notice:Modications made to the engine,
transmission, exhaust, intake, or fuel system of
your vehicle or the replacement of the original tires
with other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and can cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This could
also result in a failure to pass a required Emission
Inspection/Maintenance test. SeeAccessories
and Modifications on page 6-3.
This light comes on briey, as a check to show it is
working, as you start the engine. If the light does not
come on, have it repaired. This light also comes
on during a malfunction in one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and could damage the emission control system
on your vehicle. Diagnosis and service might
be required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service might be required.
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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

Emissions Inspection and
Maintenance Programs
Some state/provincial and local governments have
or might 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.
To perform a check engine light bulb check with the
keyless ignition, make sure the transmitter fob is
in the passenger compartment. SeeIgnition Positions
on page 2-23. Press the bottom of the Acc. button
on the instrument panel and hold the button down for
ve seconds. The instrument panel, including the check
engine light, will light up and the ignition will be on,but the engine will not start — if you press the bottom
of the Acc. button only briey, less than ve seconds,
the accessory power mode will be turned on, but not
the ignition. After the bulb check, be sure to press and
release the Acc. button again to turn the ignition off
and avoid draining the vehicle’s battery.
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 the battery or
if the 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 dealer/retailer can prepare
the vehicle for inspection.
3-56

If the driver remains unbuckled when the ignition is
on and the vehicle is in motion, the reminder will
be repeated. If the driver’s safety belt is already buckled,
this message and chime will not come on.
This message is an additional reminder to the Safety
Belt Reminder Light in the instrument panel cluster.
SeeSafety Belt Reminders on page 3-46for more
information.
CHANGE OIL NOW
This message displays when the life of the engine oil
has expired. SeeScheduled Maintenance on page 7-4.
After an oil change, the Oil Life Indicator must be
reset. SeeOil Life Indicator on page 3-80andEngine
Oil Life System on page 6-20.
CHARGE SYSTEM FAULT
This message displays when a problem with the
charging system has been detected. Have your vehicle
serviced by your dealer/retailer.
CHECK GAS CAP
This message displays if the fuel cap has not been
fully tightened. Check the fuel cap to make sure that
it is on properly.
CLEAN RADAR CRUISE
If your vehicle has this feature, this message displays
when the Adaptive Cruise Control (ACC) system is
disabled because the radar is blocked and cannot
detect vehicles in your path. It may also activate during
heavy rain or due to road spray. To clean the system,
seeAdaptive Cruise Control on page 3-15.
CLOSE CARGO DIVIDER
This message displays if the cargo divider is not in
place. Open the trunk and make sure the cargo divider
is secure and no objects are on the divider. See
Rear Storage Area on page 2-53for more information.
COOLANT OVER TEMP (Temperature)
This message displays when the engine coolant
temperature is too hot. Stop and allow your vehicle to
idle in PARK (P) until it cools down and the message
is removed. Do not increase engine speed above
a normal idle. If it does not cool down, turn off the
engine and have your vehicle serviced by your
dealer/retailer before driving it again. Severe engine
damage can result from an overheated engine.
SeeEngine Overheating on page 6-27.
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SERVICE VEHICLE SOON
This message displays when a non-emissions related
powertrain malfunction occurs. Have your vehicle
serviced by your dealer/retailer as soon as possible.
SHIFT TO PARK
This message displays if the vehicle is not in PARK (P)
when the engine is being turned off. The vehicle will
be in accessory mode. Once the shift lever is moved
to PARK (P), the vehicle will turn off.
STABILITRAK ACTIVE
You may see this message on the DIC. It means that
an advanced, computer-controlled system has come on
to help your vehicle continue to go in the direction in
which you are steering. This stability enhancement
system activates when the computer senses that your
vehicle is just starting to spin, as it might if you hit
a patch of ice or other slippery spot on the road.
When the system is on, you may hear a noise or
feel a vibration in the brake pedal. This is normal.When this message is on, continue to steer in the
direction you want to go. The system is designed to
help you in bad weather or other difficult driving situations
by making the most of whatever road conditions will
permit. If this message comes on, you will know that
something has caused your vehicle to start to spin,
so consider slowing down. A single chime also sounds
when this message is displayed.
STABILITRAK READY
If this message displays and a chime sounds, the
system has completed the functional check of the
StabiliTrak
®System.
STABILITRAK WARMING
When you rst start your vehicle and drive away,
especially during cold winter weather, this message
may display along with a chime and the traction control
warning light. This is normal. You can acknowledge
this message by pressing the RESET button. The
StabiliTrak
®System performance is affected until the
STABILITRAK READY message is displayed in the DIC,
which can take up to 15 minutes.
3-72

Antilock Brake System (ABS)
Your vehicle has the Antilock Brake System (ABS), an
advanced electronic braking system that will help
prevent a braking skid.
When you start the engine and begin to drive away,
ABS will check itself. You might hear a momentary
motor or clicking noise while this test is going on, and
you might even notice that the brake pedal moves
a little. This is normal.
If there is a problem with
ABS, this warning light will
stay on. SeeAntilock
Brake System Warning
Light on page 3-51.
Let us say the road is wet and you are driving safely.
Suddenly, an animal jumps out in front of you. You slam
on the brakes and continue braking. Here is what
happens with ABS:
A computer senses that wheels are slowing down.
If one of the wheels is about to stop rolling, the computer
will separately work the brakes at each wheel.ABS can change the brake pressure faster than any
driver could. The computer is programmed to make the
most of available tire and road conditions. This can
help you steer around the obstacle while braking hard.
As you brake, the computer keeps receiving updates on
wheel speed and controls braking pressure accordingly.
Remember: ABS does not change the time you need to
get your foot up to the brake pedal or always decrease
stopping distance. If you get too close to the vehicle
in front of you, you will not have time to apply the brakes
if that vehicle suddenly slows or stops. Always leave
enough room up ahead to stop, even though you
have ABS.
Using ABS
Do not pump the brakes. Just hold the brake pedal
down rmly and let antilock work for you. You might hear
a motor or clicking noise and feel the brake pedal
move a little during a stop, but this is normal.
Braking in Emergencies
With ABS, you can steer and brake at the same time.
In many emergencies, steering can help you more than
even the very best braking.
5-5

Automatic Transmission Fluid
How to Check Automatic Transmission
Fluid
It is not necessary to check the transmission uid level.
A transmission uid leak is the only reason for uid
loss. If a leak occurs, take the vehicle to the
dealer/retailer service department and have it repaired
as soon as possible.
There is a special procedure for checking and changing
the transmission uid. Because this procedure is difficult,
you should have this done at the dealer/retailer service
department. Contact your dealer/retailer for additional
information or the procedure can be found in the service
manual. To purchase a service manual, seeService
Publications Ordering Information on page 8-16.
Notice:Use of the incorrect automatic transmission
uid may damage your vehicle, and the damages
may not be covered by your warranty. Always
use the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 7-11.
Change the uid and lter at the intervals listed in
Additional Required Services on page 7-5, and be sure
to use the uid listed inRecommended Fluids and
Lubricants on page 7-11.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem with
engine overheating, seeEngine Overheating on
page 6-27.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Giving freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at the rst maintenance
service after each 30,000 miles (50 000 km) or
24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
6-24

Additional Required Services (cont’d)
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)
Engine cooling system service (or every
ve years, whichever occurs rst).
An Emission Control Service.
See footnote (g).•
4.4L Supercharged Engine: Intercooler
system service (or every ve years,
whichever occurs rst).See footnote (k).•
Inspect engine accessory drive belt.
An Emission Control Service.
See footnote (j).•
Maintenance Footnotes
(a)A fluid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired
and the fluid level checked. Add fluid if needed.
(b)Inspect wiper blades for wear, cracking, or
contamination. Clean the windshield and wiper blades,
if contaminated. Replace wiper blades that are worn
or damaged. See Windshield Wiper Blade Replacement
on page 6-50 and Windshield and Wiper Blades on
page 6-85 for more information.(c)Make sure the safety belt reminder light and safety
belt assemblies are working properly. Look for any other
loose or damaged safety belt system parts. If you see
anything that might keep a safety belt system from doing
its job, have it repaired. Have any torn or frayed
safety belts replaced. Also see Checking the Restraint
Systems on page 1-52.
7-6