2008 CADILLAC DTS service

Headlamp Aiming
The vehicle has a visual optical headlamp aiming
system. The aim has been preset at the factory and
should need no further adjustment.
However, if the vehicle is damaged in a crash, the
headlamp aim may be affected and adjustment may
be necessary.
If oncoming vehicles ash their high beams at you, this
may also mean the vertical aim needs to be adjusted.
It is recommended that the vehicle is taken to your
dealer/retailer for service if the headlamps need to
be re-aimed. It is possible however, to re-aim the
headlamps as described.
Notice:To make sure your headlamps are aimed
properly, read all the instructions before beginning.
Failure to follow these instructions could cause
damage to headlamp parts.The vehicle should:Be placed so the headlamps are 25 ft. (7.6 m) from
a light colored wall.
Have all four tires on a level surface which is level
all the way to the wall.
Be placed so it is perpendicular to the wall.
Not have any snow, ice, or mud on it.
Be fully assembled and all other work stopped while
headlamp aiming is being performed.
Be normally loaded with a full tank of fuel and one
person or 160 lbs (75 kg) sitting on the driver seat.
Have all tires properly inated.
Have the spare tire is in its original location in the
vehicle.
Headlamp aiming is done with the vehicle’s low-beam
headlamps. The high-beam headlamps will be correctly
aimed if the low-beam headlamps are aimed properly.
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Bulb Replacement
It is recommended that all bulbs be replaced by your
dealer/retailer.
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/retailer or a qualied technician
service them.
Your vehicle has HID headlamps. After your vehicle’s
HID headlamp bulb has been replaced, you may notice
that the beam is a slightly different shade than it was
originally. This is normal.
Windshield Wiper Blade
Replacement
Windshield wiper blades should be inspected for wear
or cracking. SeeScheduled Maintenance on page 6-4
for more information on wiper blade inspection.
Replacement blades come in different types and are
removed in different ways. Here’s how to remove
the wiper blade:
1. Turn the engine off.
2. Lift the windshield wiper arm and blade away from
the windshield.
3. Pull the clip up from the blade connecting point,
and pull the blade assembly down toward the
windshield to remove it from the wiper arm.
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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 vehicle Warranty
booklet for details.
{CAUTION:
Poorly maintained and improperly
used tires are dangerous.
Overloading your tires can cause
overheating as a result of too much
exing. You could have an air-out and
a serious accident. SeeLoading the
Vehicle on page 4-20.
CAUTION: (Continued)
CAUTION: (Continued)

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. SeeInflation - Tire
Pressure on page 5-60.
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.
SeeHigh-Speed Operation on page 5-62for
ination pressure adjustment for high
speed driving.
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Tire Sidewall Labeling
Useful information about a tire is molded into its
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.(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 the DOT code are 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 5-74.Passenger Car Tire Example
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(G) Maximum Cold Ination Load Limit:Maximum load that can be carried and the
maximum pressure needed to support that load.
For information on recommended tire pressure
seeInflation - Tire Pressure on page 5-60
andLoading the Vehicle on page 4-20.
(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. See
Spare Tire on page 5-89andIf a Tire Goes Flat on
page 5-78.
(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 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.
SeeInflation - Tire Pressure on page 5-60
andLoading the Vehicle on page 4-20.
(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 seeInflation - Tire Pressure on
page 5-60andSpare Tire on page 5-89.
(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.Compact Spare Tire Example
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(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.
(A) Tire Size
:The tire size code 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.(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) Dual Tire Maximum Load
:Maximum load
that can be carried and the maximum pressure
needed to support that load when used in a dual
conguration.
(D) 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.
(E) Tire Identication Number (TIN)
:The letters
and numbers following DOT code are 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.
(F) Tire Ply Material
:The type of cord and
number of plies in the sidewall and under the tread.
Light Truck Tire Example
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(G) Single Tire Maximum Load:Maximum load
that can be carried and the maximum pressure
needed to support that load when used as a single.
For information on recommended tire pressure see
Inflation - Tire Pressure on page 5-60.
Tire Size
The following illustration shows an example of a
tire size.
(A) 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.
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Federal Communications
Commission (FCC) and Industry
and Science Canada
The Tire Pressure Monitor System (TPMS) operates
on a radio frequency and complies with Part 15 of
the FCC Rules. Operation is subject to the following
two conditions:
1. This device may not cause harmful interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation.
The TPMS operates on a radio frequency and complies
with RSS-210 of Industry and Science Canada.
Operation is subject to the following two conditions:
1. This device may not cause interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
Changes or modications to this system by other than
an authorized service facility could void authorization to
use this equipment.
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, excluding the spare tire and wheel
assembly. 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 on the instrument
panel cluster.
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