2006 CADILLAC STS air condition

If your vehicle has the 4.4L V8 engine (VIN Code D), use
premium unleaded gasoline with a posted octane rating
of 91 or higher. For best performance, use premium
unleaded gasoline with a posted octane rating of 93. In
an emergency, you can use regular unleaded gasoline
with an octane rating of 87 or higher. If 87 octane fuel is
used, do not perform any aggressive driving maneuvers
such as wide open throttle applications. You may also
hear audible spark knock during acceleration. Rell your
tank with premium fuel as soon as possible to avoid
damaging your engine. If you are using gasoline rated at
91 octane or higher and you hear heavy knocking, your
engine needs service.
Gasoline Specications
At a minimum, gasoline should meet ASTM
specication D 4814 in the United States or
CAN/CGSB-3.5 in Canada. Some gasolines may
contain an octane-enhancing additive called
methylcyclopentadienyl manganese tricarbonyl (MMT).
General Motors recommends against the use of
gasolines containing MMT. SeeAdditives on page 5-6
for additional information.
California Fuel
If your vehicle is certied to meet California Emissions
Standards, it is designed to operate on fuels that meet
California specications. See the underhood emission
control label. If this fuel is not available in states adopting
California emissions standards, your vehicle will operate
satisfactorily on fuels meeting federal specications, but
emission control system performance may be affected.
The malfunction indicator lamp may turn on and your
vehicle may fail a smog-check test. SeeMalfunction
Indicator Lamp on page 3-67. If this occurs, return to your
authorized GM dealer for diagnosis. If it is determined
that the condition is caused by the type of fuel used,
repairs may not be covered by your warranty.
Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent engine and fuel system deposits from forming,
allowing your emission control system to work properly. In
most cases, you should not have to add anything to your
fuel. However, some gasolines contain only the minimum
amount of additive required to meet U.S. Environmental
Protection Agency regulations.
5-6

Engine Air Cleaner/Filter
The engine air cleaner/lter is in the engine
compartment on the driver’s side of the vehicle, near
the front. SeeEngine Compartment Overview on
page 5-12for more information on locating the air
cleaner/lter.
When to Inspect the Engine
Air Cleaner/Filter
Inspect the air cleaner/lter at the MaintenanceII
intervals and replace it at the rst oil change after each
50,000 mile (83 000 km) interval. SeeScheduled
Maintenance on page 6-4for more information. If you
are driving in dusty/dirty conditions, inspect the lter
at each engine oil change.
How to Inspect the Engine
Air Cleaner/Filter
To inspect the air cleaner/lter remove the lter from
the vehicle and lightly shake the lter to release
loose dust and dirt. If the lter remains caked with dirt,
a new lter is required.
To inspect or replace the lter in the 3.6L V6 or
4.6L V8 engines, do the following:
1. Remove the two screws located on the top of
the cover.
2. Disconnect the coolant recovery hose so that it
is not going across the top of the engine air
cleaner/lter.
3. Loosen the clamp and remove the duct from the
passenger’s side of the engine air cleaner/lter. 4.6L V8 Engine shown, 3.6L V6 Engine similar
5-24

If No Steam Is Coming From
Your Engine
An overheat warning, along with a CHECK COOLANT
LEVEL message, can indicate a serious problem.
If you get an engine overheat warning with no CHECK
COOLANT LEVEL message, but see or hear no
steam, the problem may not be too serious. Sometimes
the engine can get a little too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in NEUTRAL (N)
while stopped. If it is safe to do so, pull off the road,
shift to PARK (P) or NEUTRAL (N) and let the
engine idle.
2. Set the climate controls to the highest heat setting
and fan speed and open the windows, as
necessary.
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning does not come back on, you can drive
normally.If the warning continues and you have not stopped,
pull over, stop, and park your vehicle right away.
If there is still no sign of steam, you can idle the engine
for three minutes while you are parked. If you still have
the warning, turn off the engine and get everyone out of
the vehicle until it cools down. Also, see “Overheated
Engine Protection Operating Mode” later in this section.
You may decide not to lift the hood but to get service
help right away.
Overheated Engine Protection
Operating Mode
This operating mode allows your vehicle to be driven to
a safe place in an emergency. Should an overheated
engine condition exist, an overheat protection mode
which alternates ring groups of cylinders helps prevent
engine damage. In this mode, you will notice a loss
in power and engine performance. A low coolant and/or
engine overheat warning will indicate that an overheat
condition exists. Driving extended miles (km) and/or
towing a trailer in the overheat protection mode should
be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any repair.
The engine oil will be severely degraded. Repair the
cause of coolant loss and change the oil. SeeEngine
Oil on page 5-18.
5-31

Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built-in wear indicators that make
a high-pitched warning sound when the brake pads
are worn and new pads are needed. The sound
may come and go or be heard all the time your vehicle
is moving, except when you are pushing on the
brake pedal rmly.
{CAUTION:
The brake wear warning sound means that
soon your brakes will not work well. That
could lead to an accident. When you hear
the brake wear warning sound, have your
vehicle serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.Some driving conditions or climates may cause a brake
squeal when the brakes are rst applied or lightly
applied. This does not mean something is wrong with
your brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts in
the proper sequence to GM torque specications.
Brake linings should always be replaced as complete
axle sets.
Brake Pedal Travel
See your dealer if the brake pedal does not return to
normal height, or if there is a rapid increase in pedal
travel. This could be a sign of brake trouble.
Brake Adjustment
Every time you apply the brakes, with or without the
vehicle moving, your brakes adjust for wear.
5-43

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.
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.
5-60

Run-Flat Tires (STS-V)
If your vehicle has run-at tires, there is no spare tire
and no tire changing equipment. Your vehicle also has a
Tire Pressure Monitor System (TPMS) which will alert
you if there is a loss of tire pressure in any of the tires.
SeeTire Pressure Monitor System on page 5-66.
{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 vehicle’s run-at tires can operate effectively
with no air pressure for up to 50 miles (80 km) at
speeds up to 55 mph (90 km/h). The shorter the
distance you drive and the slower the speed, the greater
the chance that the tire will not have to be replaced.
When a tire is lled with air, it provides a cushion
between the road and the wheel. Because you will not
have this cushion when driving on a deated run-at
tire, try to avoid potholes that could damage your wheel
and require replacement of it.
Some road hazards can damage a tire beyond repair.
This damage could occur even before you have driven
on the tire in a deated condition. When a tire has been
damaged, or if you have driven any distance on a
deated run-at tire, check with an authorized run-at
tire service center, as soon as possible, to determine
whether the tire can be repaired or should be replaced.
5-63

To maintain your vehicle’s run-at feature, all
replacement tires must be self-supporting tires.
To locate the nearest GM or authorized run-at
servicing facility, call Roadside Service. See
Roadside Service on page 7-5for details.
{CAUTION:
Run-at tires are constructed differently than
other tires and could explode during improper
service. You or others could be injured or
killed if you attempt to repair, replace,
dismount, or mount a run-at tire. Let only
an authorized run-at service center repair,
replace, dismount, and mount run-at tires.
The valve stems on your vehicle’s run-at tires have
sensors that are part of the Tire Pressure Monitor
System (TPMS). These sensors contain batteries which
are designed to last for 10 years under normal driving
conditions. See your GM dealer, if the TPMS sensors or
a wheel ever need replacement.
Notice:Using liquid sealants can damage the tire
valves and tire pressure monitor sensors in your
vehicle’s run-at tires. This damage would not
be covered by warranty. Do not use liquid sealants
in your vehicle’s run-at tires.
Ination - Tire Pressure
Tires need the correct amount of air pressure to operate
effectively.
Notice:Do not let anyone tell you that
under-ination or over-ination is all right. It is not.
If your tires do not have enough air (under-ination),
you can get the following:
Too much exing
Too much heat
Tire overloading
Premature or irregular wear
Poor handling
Reduced fuel economy
If your tires have too much air (over-ination), you
can get the following:
Unusual wear
Poor handling
Rough ride
Needless damage from road hazards
5-64

8. Proceed to the passenger’s side rear tire, and
repeat the procedure in Step 6.
9. Proceed to the driver’s side rear tire, and repeat the
procedure in Step 6.
10. After hearing the conrming single horn chirp for the
driver’s side rear tire, a double horn chirp will sound
to signal the tire matching mode is no longer active.
Press the push-button ignition switch to ACC.
11. Set all four tires to the recommended air pressure
level as indicated on the tire and loading
information label.
12. Put the valve caps back on the valve stems.
The spare tire does not have a TPMS sensor. If you
replace one of the road tires with the spare, the
SERVICE TIRE MONITOR message will be displayed
on the DIC screen. This message should go off
once you re-install the road tire containing the TPM
sensor. The SERVICE TIRE MONITOR message is also
displayed when the TPMS system is malfunctioning.
One or more missing or inoperable TPMS sensors will
cause the SERVICE TIRE MONITOR message to
be displayed. See your GM dealer for service.Federal Communications Commission
(FCC) and Industry and Science
Canada
This device complies with Part 15 of the FCC Rules.
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.
This device complies with RSS-210 of Industry 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.
5-69