5-5 CADILLAC STS 2005 1.G User Guide

8. Turn the vertical aiming screw until the headlamp
beam is aimed to the horizontal tape line. If you
turn it clockwise, it will raise the beam and if
you turn it counterclockwise, it will lower the beam.
The top edge of the cut-off should be positioned
at the bottom edge of the horizontal tape line.
9. Repeat Steps 7 and 8 for the opposite headlamp.
Bulb Replacement
For the proper type of replacement bulbs, see
Replacement Bulbs on page 5-51.
For any bulb changing procedure not listed in this
section, contact your dealer.
High Intensity Discharge (HID)
Lighting
{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 qualied technician service them.
Your vehicle may have HID headlamps and fog lamps.
After your vehicle’s HID headlamp or fog lamp bulb has
been replaced, you may notice that the beam is a slightly
different shade than it was originally. This is normal.
5-48

Sidemarker Lamps
To replace a sidemarker lamp bulb, do the following:
1. Locate the rear sidemarker lamp assembly
under the rear bumper.
2. Turn the socket
counterclockwise and
then pull it straight
out from the
sidemarker lamp
assembly.
3. Pull the old bulb straight out and reinstall
the new bulb.
4. Reverse Step 2 to reinstall the socket.
Back-Up Lamps
To replace a back-up lamp bulb, do the following:
1. Open the trunk. SeeTrunk on page 2-14for more
information.2. Pull out the push pins holding down the top portion
of the cloth cover.
3. Fold the cover down slightly and locate the lamp
assembly.
4. Turn the socket counterclockwise and pull it straight
out to remove it from the lamp assembly.
5. Pull the old bulb straight out and reinstall the
new bulb.
6. Reverse the steps to reinstall.
5-50

Replacement Bulbs
Exterior Lamps Bulb Number
Back-up 3157K
Front Turn Signal 3757KA
Rear Sidemarker W3W
For replacement bulbs not listed here, contact your
dealer.
Windshield Replacement
Keep in mind that your windshield is part of the Head-Up
Display (HUD) system. If you ever have to get your
windshield replaced, be sure to get one that is designed
for HUD or your HUD image may look blurred or out
of focus.
Windshield Wiper Blade
Replacement
Windshield wiper blades should be inspected for wear
or cracking. SeeScheduled Maintenance on page 6-4.
It’s a good idea to clean or replace the wiper blade
assembly on a regular basis or when worn. For proper
windshield wiper blade length and type, seeNormal
Maintenance Replacement Parts on page 6-14.
To replace the wiper blade assembly, do the following:
1. Turn the ignition to OFF/ACC, with the engine off.
2. Turn on the windshield wipers and turn them off
again when the wipers are in the out-wipe
position. The driver’s side blade will be straight up
and down on the windshield.
3. Pull the windshield wiper assembly away from the
windshield.
5-51

4. Squeeze the tabs on each side of the wiper blade
assembly and slide the assembly off the end of the
wiper arm.5. Replace the blade assembly with a new one.
Allowing the wiper blade arm to touch the windshield
when no wiper blade is installed could damage
the windshield. Any damage that occurs would not
be covered by your warranty. Do not allow the
wiper blade arm to touch the windshield.
6. Repeat the steps for the other wiper.
5-52

Tires
Your new vehicle comes with high-quality tires made by
a leading tire manufacturer. If you ever have questions
about your tire warranty and where to obtain service,
see your GM Warranty booklet for details. For additional
information refer to the tire manufacturer’s booklet
included with your vehicle’s Owner’s Manual.{CAUTION:
Poorly maintained and improperly used
tires are dangerous.
Overloading your tires can cause
overheating as a result of too much
friction. You could have an air-out and a
serious accident. SeeLoading Your
Vehicle on page 4-30.
Underinated tires pose the same danger
as overloaded tires. The resulting accident
could cause serious injury. Check all tires
frequently to maintain the recommended
pressure. Tire pressure should be checked
when your tires are cold.
Overinated tires are more likely to be cut,
punctured, or broken by a sudden
impact — such as when you hit a pothole.
Keep tires at the recommended pressure.
Worn, old tires can cause accidents. If your
tread is badly worn, or if your tires have
been damaged, replace them.
SeeInflation - Tire Pressure on page 5-60for
ination pressure adjustment for high speed
driving.
5-53

Winter Tires
If you expect to drive on snow or ice covered roads
often, you may want to get winter tires for your vehicle.
All season tires provide good overall performance on
most surfaces but they may not offer the traction
you would like or the same level of performance as
winter tires on snow or ice covered roads.
See your dealer for details regarding winter tire
availability and proper tire selection. Also, seeBuying
New Tires on page 5-68
If you choose to use winter tires:
Use tires of the same brand and tread type on all
four wheel positions.
Use only radial ply tires of the same size, load
range, and speed rating as the original equipment
tires.
Winter tires with the same speed rating as your original
equipment tires may not be available for H, V, W
and ZR speed rated tires. If you choose winter tires with
a lower speed rating, never exceed the tire’s maximum
speed capability.
Tire Sidewall Labelling
Useful information about a tire is molded into its
sidewall. The examples below show a typical passenger
vehicle tire and a compact spare tire sidewall.
(A) Tire Size:The tire size is a combination of letters
and numbers used to dene a particular tire’s width,
height, aspect ratio, construction type and service
description. See the “Tire Size” illustration later in this
section for more detail.Passenger (P-Metric) Tire Example
5-54

(B) TPC Spec (Tire Performance Criteria
Specication):Original equipment tires designed to
GM’s specic tire performance criteria have a TPC
specication code molded onto the sidewall. GM’s TPC
specications meet or exceed all federal safety
guidelines.
(C) DOT (Department of Transportation):The
Department of Transportation (DOT) code indicates that
the tire is in compliance with the U.S. Department of
Transportation Motor Vehicle Safety Standards.
(D) Tire Identication Number (TIN):The letters and
numbers following DOT (Department of Transportation)
code is the Tire Identication Number (TIN). The
TIN shows the manufacturer and plant code, tire size,
and date the tire was manufactured. The TIN is molded
onto both sides of the tire, although only one side
may have the date of manufacture.(E) Tire Ply Material:The type of cord and number of
plies in the sidewall and under the tread.
(F) Uniform Tire Quality Grading (UTQG):Tire
manufacturers are required to grade tires based on three
performance factors: treadwear, traction and
temperature resistance. For more information see
Uniform Tire Quality Grading on page 5-70.
(G) Maximum Cold Ination Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load.
5-55

(A) Temporary Use Only:The compact spare tire or
temporary use tire has a tread life of approximately
3,000 miles (5 000 km) and should not be driven
at speeds over 65 mph (105 km/h). The compact spare
tire is for emergency use when a regular road tire
has lost air and gone at. If your vehicle has a compact
spare tire, seeCompact Spare Tire on page 5-84
andIf a Tire Goes Flat on page 5-74.(B) Tire Ply Material:The type of cord and number of
plies in the sidewall and under the tread.
(C) Tire Identication Number (TIN):The letters
and numbers following the DOT (Department of
Transportation) code is the Tire Identication
Number (TIN). The TIN shows the manufacturer and
plant code, tire size, and date the tire was manufactured.
The TIN is molded onto both sides of the tire, although
only one side may have the date of manufacture.
(D) Maximum Cold Ination Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load.
(E) Tire Ination:The temporary use tire or compact
spare tire should be inated to 60 psi (420 kPa).
For more information on tire pressure and ination see
Ination - Tire Pressure on page 5-60.
(F) Tire Size:A combination of letters and numbers
dene a tire’s width, height, aspect ratio, construction
type and service description. The letter T as the
rst character in the tire size means the tire is for
temporary use only.
(G) TPC Spec (Tire Performance Criteria
Specication):Original equipment tires designed to
GM’s specic tire performance criteria have a TPC
specication code molded onto the sidewall. GM’s TPC
specications meet or exceed all federal safety
guidelines. Compact Spare Tire Example
5-56

Tire Size
The following illustration shows an example of a typical
passenger vehicle tire size.
(A) Passenger (P-Metric) Tire:The United States
version of a metric tire sizing system. The letter P as
the rst character in the tire size means a passenger
vehicle tire engineered to standards set by the U.S. Tire
and Rim Association.
(B) Tire Width:The three-digit number indicates the
tire section width in millimeters from sidewall to sidewall.(C) Aspect Ratio:A two-digit number that indicates the
tire height-to-width measurements. For example, if
the tire size aspect ratio is 60, as shown in item C of
the illustration, it would mean that the tire’s sidewall is
60 percent as high as it is wide.
(D) Construction Code:A letter code is used to
indicate the type of ply construction in the tire.
The letter R means radial ply construction; the letter D
means diagonal or bias ply construction; and the
letter B means belted-bias ply construction.
(E) Rim Diameter:Diameter of the wheel in inches.
(F) Service Description:These characters represent
the load range and speed rating of the tire. The load
index represents the load carry capacity a tire is certied
to carry. The load index can range from 1 to 279. The
speed rating is the maximum speed a tire is certied
to carry a load. Speed ratings range from A to Z.
5-57

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 Ination 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. SeeInation - Tire Pressure on page 5-60.Curb Weight:This means 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 4-30.
GAWR FRT:Gross Axle Weight Rating for the front
axle, seeLoading Your Vehicle on page 4-30.
GAWR RR:Gross Axle Weight Rating for the rear axle,
seeLoading Your Vehicle on page 4-30.
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.
5-58