engine CADILLAC STS 2009 1.G Repair Manual

Before Leaving on a Long Trip
To prepare your vehicle for a long trip, consider having
it serviced by your dealer/retailer before departing.
Things to check on your own include:
Windshield Washer Fluid:Reservoir full? Windows
clean — inside and outside?
Wiper Blades:In good shape?
Fuel, Engine Oil, Other Fluids:All levels checked?
Lamps:Do they all work and are lenses clean?
Tires:Are treads good? Are tires inated to
recommended pressure?
Weather and Maps:Safe to travel? Have
up-to-date maps?
Highway Hypnosis
Always be alert and pay attention to your surroundings
while driving. If you become tired or sleepy, nd a
safe place to park your vehicle and rest.
Other driving tips include:
Keep the vehicle well ventilated.
Keep interior temperature cool.
Keep your eyes moving — scan the road ahead
and to the sides.
Check the rearview mirror and vehicle instruments
often.
4-19

Hill and Mountain Roads
Driving on steep hills or through mountains is different
than driving on at or rolling terrain. Tips for driving
in these conditions include:
Keep the vehicle serviced and in good shape.
Check all uid levels and brakes, tires, cooling
system, and transmission.
Going down steep or long hills, shift to a
lower gear.
{CAUTION:
If you do not shift down, the brakes could get so
hot that they would not work well. You would then
have poor braking or even none going down a hill.
You could crash. Shift down to let the engine
assist the brakes on a steep downhill slope.
{CAUTION:
Coasting downhill in N (Neutral) or with the ignition
off is dangerous. The brakes will have to do all the
work of slowing down and they could get so hot
that they would not work well. You would then
have poor braking or even none going down a hill.
You could crash. Always have the engine running
and the vehicle in gear when going downhill.
Stay in your own lane. Do not swing wide or cut
across the center of the road. Drive at speeds
that let you stay in your own lane.
Top of hills: Be alert — something could be in your
lane (stalled car, accident).
Pay attention to special road signs (falling rocks
area, winding roads, long grades, passing or
no-passing zones) and take appropriate action.
4-20

Blizzard Conditions
Being stuck in snow can be in a serious situation.
Stay with the vehicle unless there is help nearby.
If possible, use theRoadside Service on page 7-7.
To get help and keep everyone in the vehicle safe:
Turn on theHazard Warning Flashers on page 3-6.
Tie a red cloth to an outside mirror.
{CAUTION:
Snow can trap engine exhaust under the vehicle.
This may cause exhaust gases to get inside.
Engine exhaust contains carbon monoxide (CO)
which cannot be seen or smelled. It can cause
unconsciousness and even death.
If the vehicle is stuck in the snow:
Clear away snow from around the base of
your vehicle, especially any that is blocking
the exhaust pipe.
Check again from time to time to be sure
snow does not collect there.
CAUTION: (Continued)
CAUTION: (Continued)

Open a window about two inches on the side
of the vehicle that is away from the wind to
bring in fresh air.
Fully open the air outlets on or under the
instrument panel.
Adjust the Climate Control system to a setting
that circulates the air inside the vehicle and
set the fan speed to the highest setting.
See Climate Control System in the Index.
For more information about carbon monoxide, see
Engine Exhaust on page 2-36.
Snow can trap exhaust gases under your vehicle.
This can cause deadly CO (carbon monoxide) gas
to get inside. CO could overcome you and kill you.
You cannot see it or smell it, so you might not
know it is in your vehicle. Clear away snow from
around the base of your vehicle, especially any
that is blocking the exhaust
Run the engine for short periods only as needed to
keep warm, but be careful.
To save fuel, run the engine for only short periods as
needed to warm the vehicle and then shut the engine off
and close the window most of the way to save heat.
4-22

Repeat this until help arrives but only when you feel
really uncomfortable from the cold. Moving about
to keep warm also helps.
If it takes some time for help to arrive, now and then
when you run the engine, push the accelerator pedal
slightly so the engine runs faster than the idle speed.
This keeps the battery charged to restart the vehicle and
to signal for help with the headlamps. Do this as little as
possible to save fuel.
If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow
Slowly and cautiously spin the wheels to free the
vehicle when stuck in sand, mud, ice, or snow.
SeeRocking Your Vehicle to Get It Out on page 4-24.
If the vehicle has a traction system, it can often help
to free a stuck vehicle. Refer to the vehicle’s traction
system in the Index. If stuck too severely for the traction
system to free the vehicle, turn the traction system off
and use the rocking method.
{CAUTION:
If you let your vehicle’s tires spin at high speed,
they can explode, and you or others could be
injured. The vehicle can overheat, causing an
engine compartment re or other damage. Spin
the wheels as little as possible and avoid going
above 35 mph (55 km/h) as shown on the
speedometer.
For information about using tire chains on the vehicle,
seeTire Chains on page 5-81.
4-23

Towing a Trailer (Vehicles With
Heavy Duty Cooling)
{CAUTION:
The driver can lose control when pulling a trailer if
the correct equipment is not used or the vehicle is
not driven properly. For example, if the trailer is
too heavy, the brakes may not work well — or
even at all. The driver and passengers could
be seriously injured. The vehicle may also be
damaged; the resulting repairs would not be
covered by the vehicle warranty. Pull a trailer only
if all the steps in this section have been followed.
Ask your dealer/retailer for advice and information
about towing a trailer with the vehicle.
Vehicles with heavy duty cooling can tow a trailer if
equipped with the proper trailer towing equipment.To identify the trailering capacity of the vehicle, read
the information in “Weight of the Trailer” that appears
later in this section.
Trailering is different than just driving the vehicle
by itself. Trailering means changes in handling,
acceleration, braking, durability and fuel economy.
Successful, safe trailering takes correct equipment,
and it has to be used properly.
The following information has many time-tested,
important trailering tips and safety rules. Many of these
are important for your safety and that of your passengers.
So please read this section carefully before pulling a
trailer.
Load-pulling components such as the engine,
transmission, rear axle, wheel assemblies and tires are
forced to work harder against the drag of the added
weight. The engine is required to operate at relatively
higher speeds and under greater loads, generating
extra heat. The trailer also adds considerably to wind
resistance, increasing the pulling requirements.
4-32

Pulling A Trailer
Here are some important points:
Do not tow a trailer at all during the rst 500 miles
(800 km) the new vehicle is driven. The engine,
axle or other parts could be damaged.
Then, during the rst 500 miles (800 km) that a
trailer is towed, do not drive over 50 mph (80 km/h)
and do not make starts at full throttle. This helps
the engine and other parts of the vehicle wear in at
the heavier loads.
Vehicles can tow in D (Drive). Shift the transmission
to a lower gear if the transmission shifts too often
under heavy loads and/or hilly conditions.
Obey speed limit restrictions when towing a trailer.
Do not drive faster than the maximum posted
speed for trailers, or no more than 55 mph
(90 km/h), to save wear on the vehicle’s parts.
Three important considerations have to do with weight:
The weight of the trailer.
The weight of the trailer tongue.
The total weight on the vehicle’s tires.
Weight of the Trailer
How heavy can a trailer safely be?
It should never weigh more than 1,000 lbs (450 kg).
But even that can be too heavy.
It depends on how the rig is used. For example, speed,
altitude, road grades, outside temperature and how much
the vehicle is used to pull a trailer are all important. It can
depend on any special equipment on the vehicle, and
the amount of tongue weight the vehicle can carry.
See “Weight of the Trailer Tongue” later in this section
for more information.
Maximum trailer weight is calculated assuming only the
driver is in the tow vehicle and it has all the required
trailering equipment. The weight of additional optional
equipment, passengers and cargo in the tow vehicle
must be subtracted from the maximum trailer weight.
Ask your dealer/retailer for our trailering information
or advice, or write us at our Customer Assistance
Offices. SeeCustomer Assistance Offices on page 7-6
for more information.
4-33

Total Weight on the Vehicle’s Tires
Be sure the vehicle’s tires are inated to the upper limit
for cold tires. These numbers can be found on the
Certication label or seeLoading the Vehicle on
page 4-24. Make sure not to go over the GVW limit for
the vehicle, or the GAWR, including the weight of
the trailer tongue.
Hitches
It is important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads
are a few reasons why the right hitch is needed.
The rear bumper on the vehicle is not intended for
hitches. Do not attach rental hitches or other
bumper-type hitches to it. Use only a frame-mounted
hitch that does not attach to the bumper.
Will any holes be made in the body of the vehicle
when the trailer hitch is installed? If so, be sure to
seal the holes when the hitch is removed. If they are
not sealed, deadly carbon monoxide (CO) from the
engine’s exhaust can get into the vehicle. See
Engine Exhaust on page 2-36. Sealing the holes will
also prevent dirt and water from entering the vehicle.
Safety Chains
Always attach chains between the vehicle and the
trailer. Cross the safety chains under the tongue of
the trailer to help prevent the tongue from contacting
the road if it becomes separated from the hitch.
Instructions about safety chains may be provided by
the hitch manufacturer or by the trailer manufacturer.
Follow the manufacturer’s recommendation for attaching
safety chains and do not attach them to the bumper.
Always leave just enough slack so the rig can turn.
Never allow safety chains to drag on the ground.
Trailer Brakes
Does the trailer have its own brakes? Be sure to read
and follow the instructions for the trailer brakes so
they are installed, adjusted and maintained properly.
Because the vehicle has StabiliTrak
®, do not try to tap
into the vehicle’s hydraulic brake system. If you do,
both brake systems will not work well, or at all.
Trailer Wiring Harness
All of the electrical circuits required for the trailer lighting
system can be accessed at the driver side rear lamp
connector. This connector is located under the carpet
on the rear corner of the trunk compartment.
4-35

Turn Signals When Towing a Trailer
The arrows on the instrument panel ash whenever
signaling a turn or lane change. Properly hooked up, the
trailer lamps also ash, telling other drivers the vehicle
is turning, changing lanes or stopping.
When towing a trailer, the arrows on the instrument
panel ash for turns even if the bulbs on the trailer
are burned out. For this reason you may think other
drivers are seeing the signal when they are not.
It is important to check occasionally to be sure the
trailer bulbs are still working.
The vehicle has bulb warning lights. When a trailer
lighting system is plugged into the vehicle’s lighting
system, its bulb warning lights may not let you know if
one of the lamps goes out. So, when the trailer lighting
system is plugged in, be sure to check the vehicle and
trailer lamps from time to time to be sure they are all
working. Once the trailer lamps are disconnected, the
bulb warning lights again can tell you if one of the vehicle
lamps is out.
Driving On Grades
Reduce speed and shift to a lower gearbeforestarting
down a long or steep downgrade. If the transmission is
not shifted down, the brakes might have to be used so
much that they would get hot and no longer work well.
On a long uphill grade, shift down and reduce the
vehicle’s speed to around 45 mph (70 km/h) to reduce
the possibility of the engine and the transmission
overheating.
Vehicles can tow in D (Drive). Shift the transmission to
a lower gear if the transmission shifts too often under
heavy loads and/or hilly conditions.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If the engine is
turned off immediately after towing at high altitude on
steep uphill grades, the vehicle may show signs similar to
engine overheating. To avoid this, let the engine run while
parked, preferably on level ground, with the automatic
transmission in P (Park) for a few minutes before turning
the engine off. If the overheat warning comes on, see
Engine Overheating on page 5-34.
4-37

Parking on Hills
{CAUTION:
Parking the vehicle on a hill with the trailer
attached can be dangerous. If something goes
wrong, the rig could start to move. People can be
injured, and both the vehicle and the trailer can be
damaged. When possible, always park the rig on a
at surface.
If parking the rig on a hill:
1. Press the brake pedal, but do not shift into P (Park)
yet. Turn the wheels into the curb if facing downhill
or into traffic if facing uphill.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking
brake and shift into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal while you:
Start the engine
Shift into a gear
Release the parking brake
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
The vehicle needs service more often when pulling a
trailer. See this manual’s Maintenance Schedule
or Index for more information. Things that are especially
important in trailer operation are automatic transmission
uid, engine oil, axle lubricant, belts, cooling system
and brake system. It is a good idea to inspect
these before and during the trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily overheat during
severe operating conditions. SeeEngine Overheating on
page 5-34.
4-38

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-4
California Perchlorate Materials Requirements......5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of
the Vehicle.................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-7
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-18
Engine Oil Life System..................................5-21
Engine Air Cleaner/Filter................................5-23
Automatic Transmission Fluid.........................5-25
Cooling System............................................5-26
Engine Coolant.............................................5-27
Coolant Surge Tank Pressure Cap..................5-34
Engine Overheating.......................................5-34Overheated Engine Protection
Operating Mode........................................5-36
Power Steering Fluid.....................................5-37
Windshield Washer Fluid................................5-38
Brakes........................................................5-39
Battery........................................................5-42
Jump Starting...............................................5-42
All-Wheel Drive..............................................5-47
Rear Axle.......................................................5-48
Front Axle......................................................5-49
Headlamp Aiming...........................................5-50
Bulb Replacement..........................................5-51
High Intensity Discharge (HID) Lighting............5-51
Halogen Bulbs..............................................5-51
Back-Up Lamps............................................5-52
Replacement Bulbs.......................................5-52
Windshield Replacement.................................5-52
Windshield Wiper Blade Replacement..............5-52
Tires..............................................................5-54
Winter Tires.................................................5-55
Tire Sidewall Labeling...................................5-56
Tire Terminology and Denitions.....................5-59
Run-Flat Tires (STS-V)..................................5-62
Ination - Tire Pressure.................................5-64
High-Speed Operation...................................5-65
Tire Pressure Monitor System.........................5-66
Tire Pressure Monitor Operation.....................5-68
Section 5 Service and Appearance Care
5-1