2007 CADILLAC DTS PROFESSIONAL wheel size

Service........................................................ 353
Accessories and Modications................... 353
California Proposition 65 Warning.............. 354
Doing Your Own Service Work.................. 354
Adding Equipment to the Outside of
Your Vehicle.......................................... 355
Fuel............................................................. 355
Gasoline Octane........................................ 356
Gasoline Specications.............................. 356
California Fuel........................................... 356
Additives................................................... 357
Fuels in Foreign Countries........................ 358
Filling the Tank......................................... 358
Filling a Portable Fuel Container............... 361
Checking Things Under the Hood.............. 362
Hood Release........................................... 363
Engine Compartment Overview.................. 364
Engine Oil................................................. 365
Engine Oil Life System.............................. 368
Engine Air Cleaner/Filter............................ 370
Automatic Transaxle Fluid......................... 372
Engine Coolant.......................................... 374
Coolant Surge Tank Pressure Cap............ 377
Engine Overheating................................... 377Overheated Engine Protection
Operating Mode..................................... 379
Cooling System......................................... 380
Power Steering Fluid................................. 385
Windshield Washer Fluid........................... 386
Brakes...................................................... 387
Battery...................................................... 390
Jump Starting............................................ 392
Headlamp Aiming........................................ 397
Bulb Replacement....................................... 400
High Intensity Discharge (HID) Lighting..... 400
Windshield Wiper Blade Replacement....... 400
Tires............................................................ 402
Tire Sidewall Labeling............................... 403
Tire Terminology and Denitions............... 408
Ination - Tire Pressure............................. 411
High-Speed Operation............................... 413
Tire Pressure Monitor System................... 414
Tire Inspection and Rotation...................... 418
When It Is Time for New Tires.................. 419
Buying New Tires...................................... 420
Different Size Tires and Wheels................ 422
Uniform Tire Quality Grading..................... 422
Section 5 Service and Appearance Care
351

(F) Tire Ply Material:The type of cord and
number of plies in the sidewall and under
the tread.
(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 seeInation - Tire Pressure on
page 411.
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.
407

Tire Pressure Monitor System
The Tire Pressure Monitor System (TPMS) uses
radio and sensor technology to check tire pressure
levels. Sensors are mounted on each tire and
wheel assembly, except the spare tire. The TPMS
sensors monitor the air pressure in your vehicle’s
tires and transmit tire pressure readings to a
receiver located in the vehicle.
When a low tire pressure condition is detected,
the TPMS will illuminate the low tire pressure
warning symbol located on the instrument panel
cluster. A Driver Information Center (DIC) message
to check the pressure in a specic tire will also
appear on the DIC display. The low tire pressure
warning symbol on the instrument panel cluster
and the CHECK TIRE PRESSURE message
on the DIC display will appear at each ignition
cycle until the tires are inated to the correct
ination pressure. For additional information and
details about the DIC operation and displays
seeDIC Controls and Displays on page 240and
DIC Warnings and Messages on page 246.
You may notice, during cooler weather conditions,
that the low tire pressure warning symbol and
the CHECK TIRE PRESSURE message willdisplay when the vehicle is rst started and then
turn off as you start to drive the vehicle. This could
be an early indicator that the tire pressures are
getting low and need to be checked and inated to
the proper pressure.
Each tire, including the spare (if provided), should
be checked monthly when cold and inated to
the ination pressure recommended by the vehicle
manufacturer on the vehicle placard or tire
ination pressure label. (If your vehicle has tires of
a different size than the size indicated on the
vehicle placard or tire ination pressure label, you
should determine the proper tire ination
pressure for those tires.)
As an added safety
feature, your vehicle has
been equipped with a
tire pressure monitoring
system (TPMS) that
illuminates a low tire
pressure telltale when
one or more of your tires
is signicantly
under-inated.
414

Accordingly, when the low tire pressure telltale
illuminates, you should stop and check your tires
as soon as possible, and inate them to the
proper pressure. Driving on a signicantly
under-inated tire causes the tire to overheat and
can lead to tire failure. Under-ination also
reduces fuel efficiency and tire tread life, and may
affect the vehicle’s handling and stopping ability.
Please note that the TPMS is not a substitute
for proper tire maintenance, and it is the driver’s
responsibility to maintain correct tire pressure,
even if under-ination has not reached the level
to trigger illumination of the TPMS low tire
pressure telltale.
Your vehicle has also been equipped with a TPMS
malfunction indicator to indicate when the
system is not operating properly. The TPMS
malfunction indicator is combined with the low tire
pressure telltale. When the system detects a
malfunction, the telltale will ash for approximately
one minute and then remain continuously
illuminated. This sequence will continue upon
subsequent vehicle start-ups as long as the
malfunction exists.When the malfunction indicator is illuminated, the
system may not be able to detect or signal low
tire pressure as intended. TPMS malfunctions may
occur for a variety of reasons, including the
installation of replacement or alternate tires or
wheels on the vehicle that prevent the TPMS from
functioning properly. Always check the TPMS
malfunction telltale after replacing one or more
tires or wheels on your vehicle to ensure that the
replacement or alternate tires and wheels allow
the TPMS to continue to function properly.
A Tire and Loading Information Label, attached to
your vehicle, shows the size of your vehicle’s
original tires and the correct ination pressure for
your vehicle’s tires when they are cold. See
Loading Your Vehicle on page 333, for the location
of the Tire and Loading Information label. Also
seeInation - Tire Pressure on page 411.
Your vehicle’s TPMS can alert you about a low
tire pressure condition but it does not replace
normal tire maintenance. SeeTire Inspection and
Rotation on page 418andTires on page 402.
Notice:Do not use a tire sealant if your vehicle
has Tire Pressure Monitors. The liquid sealant
can damage the tire pressure monitor sensors.
415

Resetting the TPMS Sensor
Identication Codes
Each TPMS sensor has a unique identication
code. Any time you replace one or more of
the TPMS sensors, rotate the vehicle’s tires, or
install a full-size spare that has a TPMS sensor,
the sensor’s identication codes will need to
be matched to the new tire/wheel position. Each
tire/wheel position is matched to the TPMS sensor
using a TPMS diagnostic tool. See your GM
dealer for service.
The TPMS sensors may also be matched to each
tire/wheel position by increasing or decreasing
the tire’s air pressure. When increasing the tire’s
air pressure, do not exceed the maximum tire
pressure indicated on the tire’s sidewall.
You will have two minutes to match the rst
tire/wheel position, and ve minutes overall, to
match all four tire/wheel positions. If it takes longer
than two minutes, to match the rst tire and
wheel, or more than ve minutes to match all
four tire and wheel positions the matching process
stops and you will need to start over.The TPMS matching process is outlined below:
1. Set the parking brake.
2. Turn the ignition switch to RUN with the
engine off.
3. Press the Driver Information Center (DIC)
vehicle information button until the PRESS
VTO RELEARN TIRE POSITIONS displays.
4. Press the set/reset button to allow the system
to learn the tire positions. The horn will sound
twice to indicate that the TPMS is ready,
and then the message TIRE LEARNING
ACTIVE will display. The sensor matching
process can begin.
5. Start with the driver’s side front tire.
6. Remove the valve cap from the valve stem.
Activate the TPMS sensor by increasing or
decreasing the tire’s air pressure for
ve seconds, or until a horn chirp sounds. The
horn chirp, which may take up to 30 seconds,
conrms that the sensor identication code has
been matched to this tire position. To decrease
the tire’s air-pressure use the pointed end of
the valve cap, a pencil-style air pressure gage
or a key.
416

Tire Inspection and Rotation
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km).
Any time you notice unusual wear, rotate your
tires as soon as possible and check wheel
alignment. Also check for damaged tires or wheels.
SeeWhen It Is Time for New Tires on page 419
andWheel Replacement on page 424for
more information.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The
rst rotation is the most important. SeeScheduled
Maintenance on page 465.If your vehicle has a compact spare tire, it should
not be included in the tire rotation process.
Use the four-tire rotation pattern shown.
A ve-tire rotation pattern may be used for your
professional vehicle, if it has a full-size spare
tire and wheel assembly that matches the original
equipment tires and wheels in size, type and
brand. The correct ve-tire rotation pattern
is shown.
After the tires have been rotated, adjust the front
and rear ination pressures as shown on the
Tire and Loading Information label. SeeLoading
Your Vehicle on page 333.
Four-Tire Rotation Pattern
Five-Tire Rotation Pattern
418

Vehicles that have the Tire Pressure Monitor
System (TPMS) will need to have the sensors
reset after a tire rotation is performed. See
Tire Pressure Monitor System on page 414.
Make certain that all wheel nuts are properly
tightened. See “Wheel Nut Torque” under
Capacities and Specications on page 460.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after time. The wheel could
come off and cause an accident. When
you change a wheel, remove any rust or
dirt from places where the wheel attaches
to the vehicle. In an emergency, you can
use a cloth or a paper towel to do this;
but be sure to use a scraper or wire brush
later, if needed, to get all the rust or dirt
off. SeeChanging a Flat Tire on page 428.
When It Is Time for New Tires
One way to tell when it is
time for new tires is to
check the treadwear
indicators, which will
appear when your tires
have only 1/16 inch
(1.6 mm) or less of
tread remaining.
You need a new tire if any of the following
statements are true:
You can see the indicators at three or more
places around the tire.
You can see cord or fabric showing through
the tire’s rubber.
The tread or sidewall is cracked, cut, or
snagged deep enough to show cord or fabric.
The tire has a bump, bulge, or split.
The tire has a puncture, cut, or other damage
that cannot be repaired well because of the
size or location of the damage.
419

Buying New Tires
GM has developed and matched specic tires for
your vehicle. The original equipment tires
installed on your vehicle, when it was new, were
designed to meet General Motors Tire
Performance Criteria Specication (TPC spec)
system rating. If you need replacement tires, GM
strongly recommends that you get tires with
the same TPC Spec rating. This way, your vehicle
will continue to have tires that are designed to
give the same performance and vehicle safety,
during normal use, as the original tires.
GM’s exclusive TPC Spec system considers over
a dozen critical specications that impact the
overall performance of your vehicle, including
brake system performance, ride and handling,
traction control, and tire pressure monitoring
performance. GM’s TPC Spec number is molded
onto the tire’s sidewall by the tire manufacturer.
If the tires have an all-season tread design,
the TPC spec number will be followed by an MS
for mud and snow. SeeTire Sidewall Labeling
on page 403for additional information.{CAUTION:
Mixing tires could cause you to lose
control of your vehicle while driving. If you
mix tires of different sizes, brands, or types
(radial and bias-belted tires), the vehicle
may not handle properly, and you could
have a crash. Using tires of different sizes,
brands, or types may also cause damage to
your vehicle. Be sure to use the correct
size, brand, and type of tires on all wheels.
Your vehicle may have a compact spare
tire and wheel assembly. If the vehicle has
a compact spare tire and wheel, they have
the same overall diameter as your vehicle’s
full-size tires and wheels. Because they
were designed and developed for use on
your vehicle, it is all right to drive your
vehicle with the compact spare installed
properly. Compact spare tires are designed
for temporary use only. SeeSpare Tire on
page 438.
420