2008 CADILLAC XLR light

4. At the wall or other at surface, measure from the
ground upward (A) to the recorded distance from
Step 3 and mark it.
Notice:Do not cover a headlamp to improve beam
cut-off when aiming. Covering a headlamp may
cause excessive heat build-up which may cause
damage to the headlamp.
5. Draw or tape a horizontal line (B) on the wall or at
surface the width of the vehicle at the height of the
mark in Step 4.6. Turn on the low-beam headlamps and place a
piece of cardboard in front of the headlamp not
being aimed. This should allow only the beam of
light from the headlamp being aimed to be seen on
the at surface.
7. Locate the vertical headlamp aiming screws, which
are under the hood near each headlamp assembly.
The adjustment screw can be turned with a 6 mm
male hex.
8. Turn the vertical
aiming screw until the
headlamp beam is
aimed to the horizontal
tape line.
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9. The top edge of the cut-off should be positioned at
the bottom edge of the horizontal tape line.
10. Make sure that the light from the headlamp is
positioned at the bottom edge of the horizontal tape
line. The lamp on the left (A) shows the correct
headlamp aim. The lamp on the right (B) shows the
incorrect headlamp aim.
11. Repeat Steps 7 through 9 for the opposite
headlamp.Bulb Replacement
It is recommended that all bulbs be replaced by your
dealer/retailer.
Windshield Replacement
Your windshield is part of the Head-Up Display (HUD)
system. If you ever have to get your windshield
replaced, get one that is designed for HUD or your
HUD image may look out of focus.
Windshield Wiper Blade
Replacement
Windshield wiper blades should be inspected for wear
and cracking. SeeScheduled Maintenance on page 7-4
for more information.
Replacement blades come in different types and are
removed in different ways. For proper type and length,
seeNormal Maintenance Replacement Parts on
page 7-13.
6-50

Tire Terminology and Denitions
Air Pressure:The amount of air inside the
tire pressing outward on each square inch of the
tire. Air pressure is expressed in pounds per
square inch (psi) or kilopascal (kPa).
Accessory Weight
:This means the combined
weight of optional accessories. Some examples of
optional accessories are, automatic transmission,
power steering, power brakes, power windows,
power seats, and air conditioning.
Aspect Ratio
:The relationship of a tire’s height
to its width.
Belt
:A rubber coated layer of cords that is located
between the plies and the tread. Cords may be
made from steel or other reinforcing materials.
Bead
:The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the rim.
Bias Ply Tire
:A pneumatic tire in which the plies
are laid at alternate angles less than 90 degrees
to the centerline of the tread.
Cold Tire Pressure
:The amount of air pressure in
a tire, measured in pounds per square inch (psi) or
kilopascals (kPa) before a tire has built up heat
from driving. SeeInflation - Tire Pressure on
page 6-60.Curb Weight
:The weight of a motor vehicle with
standard and optional equipment including the
maximum capacity of fuel, oil, and coolant,
but without passengers and cargo.
DOT Markings
:A code molded into the sidewall
of a tire signifying that the tire is in compliance
with the U.S. Department of Transportation (DOT)
motor vehicle safety standards. The DOT code
includes the Tire Identication Number (TIN),
an alphanumeric designator which can also identify
the tire manufacturer, production plant, brand,
and date of production.
GVWR
:Gross Vehicle Weight Rating. SeeLoading
Your Vehicle on page 5-22.
GAWR FRT
:Gross Axle Weight Rating for the
front axle. SeeLoading Your Vehicle on page 5-22.
GAWR RR
:Gross Axle Weight Rating for the rear
axle. SeeLoading Your Vehicle on page 5-22.
Intended Outboard Sidewall
:The side of
an asymmetrical tire, that must always face
outward when mounted on a vehicle.
Kilopascal (kPa)
:The metric unit for air pressure.
Light Truck (LT-Metric) Tire
:A tire used on
light duty trucks and some multipurpose passenger
vehicles.
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Load Index:An assigned number ranging from
1 to 279 that corresponds to the load carrying
capacity of a tire.
Maximum Ination Pressure
:The maximum air
pressure to which a cold tire can be inated.
The maximum air pressure is molded onto the
sidewall.
Maximum Load Rating
:The load rating for a tire
at the maximum permissible ination pressure
for that tire.
Maximum Loaded Vehicle Weight
:The sum of
curb weight, accessory weight, vehicle capacity
weight, and production options weight.
Normal Occupant Weight
:The number of
occupants a vehicle is designed to seat multiplied
by 150 lbs (68 kg). SeeLoading Your Vehicle
on page 5-22.
Occupant Distribution
:Designated seating
positions.
Outward Facing Sidewall
:The side of an
asymmetrical tire that has a particular side that
faces outward when mounted on a vehicle.
The side of the tire that contains a whitewall,
bears white lettering, or bears manufacturer,
brand, and/or model name molding that is higher
or deeper than the same moldings on the
other sidewall of the tire.Passenger (P-Metric) Tire
:A tire used on
passenger cars and some light duty trucks and
multipurpose vehicles.
Recommended Ination Pressure
:Vehicle
manufacturer’s recommended tire ination
pressure as shown on the tire placard.
SeeInflation - Tire Pressure on page 6-60
andLoading Your Vehicle on page 5-22.
Radial Ply Tire
:A pneumatic tire in which the
ply cords that extend to the beads are laid at
90 degrees to the centerline of the tread.
Rim
:A metal support for a tire and upon which
the tire beads are seated.
Sidewall
:The portion of a tire between the tread
and the bead.
Speed Rating
:An alphanumeric code assigned to
a tire indicating the maximum speed at which a
tire can operate.
Traction
:The friction between the tire and the
road surface. The amount of grip provided.
Tread
:The portion of a tire that comes into
contact with the road.
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Treadwear Indicators:Narrow bands, sometimes
called wear bars, that show across the tread of
a tire when only 1/16 inch (1.6 mm) of tread
remains. SeeWhen It Is Time for New Tires on
page 6-66.
UTQGS (Uniform Tire Quality Grading
Standards)
:A tire information system that
provides consumers with ratings for a tire’s
traction, temperature, and treadwear. Ratings are
determined by tire manufacturers using
government testing procedures. The ratings are
molded into the sidewall of the tire. SeeUniform
Tire Quality Grading on page 6-69.
Vehicle Capacity Weight
:The number of
designated seating positions multiplied by
150 lbs (68 kg) plus the rated cargo load.
SeeLoading Your Vehicle on page 5-22.
Vehicle Maximum Load on the Tire
:Load on
an individual tire due to curb weight, accessory
weight, occupant weight, and cargo weight.
Vehicle Placard
:A label permanently attached to
a vehicle showing the vehicle’s capacity weight
and the original equipment tire size and
recommended ination pressure. See “Tire and
Loading Information Label” underLoading
Your Vehicle on page 5-22.
Run-Flat Tires
Your vehicle, when new, had run-at tires. There is no
spare tire, no tire changing equipment, and no place
to store a tire in the vehicle. Run-at tires perform
so well without any air that a Tire Pressure Monitor
System (TPMS) is used to alert you if a tire has
lost pressure.
{CAUTION:
When the low tire warning light is displayed on
the instrument panel cluster, your vehicle’s
handling capabilities will be reduced during
severe maneuvers. If you drive too fast, you
could lose control of your vehicle. You or others
could be injured. Do not drive over 55 mph
(90 km/h) when the low tire warning light is
displayed. Drive cautiously and check your tire
pressures as soon as you can.
If a tire goes at, you will not need to stop on the side
of the road to change the tire. You can just keep on
driving. The shorter the distance you drive and the
slower the speed, the greater the chance that the tire
6-58

Tire Pressure Monitor Operation
The Tire Pressure Monitor System (TPMS) is designed
to warn the driver when a low tire pressure condition
exists. TPMS sensors are mounted onto each tire
and wheel assembly on your vehicle. The TPMS
sensors monitor the air pressure in the vehicle’s tires
and transmits the tire pressure readings to a receiver
located in the vehicle.
When a low tire pressure
condition is detected, the
TPMS illuminates the
low tire pressure warning
light, located in the
instrument panel cluster.
At the same time a message to check the pressure in a
specic tire appears on the Driver Information Center
(DIC) display. The low tire pressure warning light
and the DIC warning message appear at each ignition
cycle until the tires are inated to the correct ination
pressure. Using the DIC, tire pressure levels canbe viewed by the driver. For additional information and
details about the DIC operation and displays see
DIC Operation and Displays on page 3-60andDIC
Warnings and Messages on page 3-63.
The low tire pressure warning light may come on in cool
weather when the vehicle is rst started, and then
turn off as you start to drive. This could be an early
indicator that the air pressure in the tire(s) are getting
low and need to be inated to the proper pressure.
A Tire and Loading Information label, attached to your
vehicle, shows the size of your vehicle’s original
equipment tires and the correct ination pressure for
your vehicle’s tires when they are cold. SeeLoading
Your Vehicle on page 5-22, for an example of the
Tire and Loading Information label and its location on
your vehicle. Also seeInflation - Tire Pressure on
page 6-60for additional information.
Your vehicle’s TPMS can warn you about a low tire
pressure condition but it does not replace normal
tire maintenance. SeeTire Inspection and Rotation on
page 6-65,When It Is Time for New Tires on page 6-66,
andTires on page 6-52.
Notice:Liquid tire sealants could damage the
Tire Pressure Monitor System (TPMS) sensors.
Sensor damage caused by using a tire sealant is not
covered by your warranty. Do not use liquid tire
sealants.
6-63

TPMS Malfunction Light and Message
The TPMS will not function properly if one or more of the
TPMS sensors are missing or inoperable. When the
system detects a malfunction, the low tire warning light
ashes for about one minute and then stays on for
the remainder of the ignition cycle. A DIC warning
message is also displayed. The low tire warning light
and DIC warning message come on at each ignition
cycle until the problem is corrected. Some of the
conditions that can cause the malfunction light and
DIC message to come on are:
The TPMS sensor matching process was not done
or not completed successfully. The DIC message
should go off after successfully completing the
sensor matching process.
One or more TPMS sensors are missing or
damaged. Under these conditions the TPMS
malfunction light (low tire warning light) comes on,
and at the same time the DIC message is
displayed. The DIC message and TPMS malfunction
light should go off once the TPMS sensors are
installed and the sensor matching process is
performed successfully.
Replacement tires or wheels do not match your
vehicle’s original equipment tires or wheels.
Tires and wheels other than those recommended
for your vehicle could prevent the TPMS from
functioning properly. SeeBuying New Tires on
page 6-67.
Operating electronic devices or being near facilities
using radio wave frequencies similar to the TPMS
could cause the TPMS sensors to malfunction.
If the TPMS is not functioning it cannot detect or
signal a low tire condition. See your dealer/retailer for
service if the TPMS malfunction light and DIC message
comes on and stays on.
TPMS Sensor Matching Process
Each TPMS sensor has a unique identication code.
Any time you replace one or more of the TPMS sensors
or rotate your vehicle’s tires, the identication codes
will need to be matched to the new tire/wheel position.
The sensors are matched to the tire/wheel positions
in the following order: driver side front tire, passenger
side front tire, passenger side rear tire, and driver
side rear tire using a TPMS diagnostic tool. See your
dealer/retailer for service.
6-64

Uniform Tire Quality Grading
Quality grades can be found where applicable on
the tire sidewall between tread shoulder and
maximum section width. For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration (NHTSA), which
grades tires by treadwear, traction, and
temperature performance. This applies only to
vehicles sold in the United States. The grades are
molded on the sidewalls of most passenger car
tires. The Uniform Tire Quality Grading (UTQG)
system does not apply to deep tread, winter-type
snow tires, space-saver, or temporary use
spare tires, tires with nominal rim diameters of
10 to 12 inches (25 to 30 cm), or to some
limited-production tires.
While the tires available on General Motors
passenger cars and light trucks may vary with
respect to these grades, they must also conform
to federal safety requirements and additional
General Motors Tire Performance Criteria (TPC)
standards.
Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specied
government test course. For example, a tire
graded 150 would wear one and a half (1.5) times
as well on the government course as a tire
graded 100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart signicantly from
the norm due to variations in driving habits, service
practices, and differences in road characteristics
and climate.
Traction – AA, A, B, C
The traction grades, from highest to lowest, are AA,
A, B, and C. Those grades represent the tire’s
ability to stop on wet pavement as measured under
controlled conditions on specied government test
surfaces of asphalt and concrete. A tire marked C
may have poor traction performance.
Warning:The traction grade assigned to this tire
is based on straight-ahead braking traction tests,
and does not include acceleration, cornering,
hydroplaning, or peak traction characteristics.
6-69