2008 CADILLAC STS Owners Manual

Do not tow a trailer at all during the rst 1,000 miles
(1 600 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.
Then, during the rst 500 miles (800 km) that you
tow a trailer, do not drive over 50 mph (80 km/h)
and do not make starts at full throttle. This
helps your engine and other parts of your vehicle
wear in at the heavier loads.
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 your 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 your 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 you plan to use your rig. For
example, speed, altitude, road grades, outside
temperature and how much your vehicle is used to pull
a trailer are all important. It can also depend on any
special equipment that you have on your 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 form the maximum trailer weight.
You can ask your dealer/retailer for our trailering
information or advice, or you can write us at our
Customer Assistance Offices. SeeCustomer Assistance
Offices on page 7-5for more information.
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Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important weight
to measure because it affects the total or gross weight
of your vehicle. The Gross Vehicle Weight (GVW)
includes the curb weight of the vehicle, any cargo you
may carry in it, and the people who will be riding in
the vehicle. If you have a lot of options, equipment,
passengers, or cargo in your vehicle, it will reduce the
tongue weight your vehicle can carry, which will also
reduce the trailer weight your vehicle can tow. And if you
tow a trailer, you must add the tongue load to the
GVW because your vehicle will be carrying that weight,
too. SeeLoading Your Vehicle on page 4-26for
more information about your vehicle’s maximum load
capacity.If you are using a weight-carrying hitch, the trailer
tongue (A) should weigh 10 to 15 percent of the total
loaded trailer weight (B).
After you have loaded your trailer, weigh the trailer and
then the tongue, separately, to see if the weights are
proper. If they are not, you may be able to get them right
simply by moving some items around in the trailer.
Total Weight on Your Vehicle’s Tires
Be sure your vehicle’s tires are inated to the upper limit
for cold tires. You will nd these numbers on the
Tire-Loading Information label. SeeLoading Your
Vehicle on page 4-26. Then be sure you do not go over
the GVW limit for your vehicle, including the weight
of the trailer tongue.
4-36

Hitches
It is important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads are
a few reasons why you will need the right hitch. Here
are some rules to follow:
The rear bumper on your 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 you have to make any holes in the body of
your vehicle when you install a trailer hitch? If
you do, then be sure to seal the holes later when
you remove the hitch. If you do not seal them,
deadly carbon monoxide (CO) from your exhaust
can get into your vehicle. SeeEngine Exhaust
on page 2-38. Dirt and water can also enter
the vehicle.
Safety Chains
You should always attach chains between your vehicle
and your trailer. Cross the safety chains under the
tongue of the trailer so that the tongue will not drop to
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 you can turn
with your rig. And, never allow safety chains to drag on
the ground.
Trailer Brakes
Does your trailer have its own brakes? Be sure to read
and follow the instructions for the trailer brakes so
you will be able to install, adjust and maintain them
properly.
Because you have anti-lock brakes, do not try to tap
into your vehicle’s 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 your trailer
lighting system can be accessed at the driver’s side rear
lamp connector. This connector is located under the
carpet on the rear corner of the trunk compartment.
4-37

Driving with a Trailer
Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you will want to
get to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the trailer.
And always keep in mind that the vehicle you are
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check all trailer hitch parts and
attachments, safety chains, electrical connector, lamps,
tires and mirror adjustment. If the trailer has electric
brakes, start your vehicle and trailer moving and then
apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer
brakes are still working.
Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
Passing
You will need more passing distance up ahead when
you are towing a trailer. And, because the vehicle
is a good deal longer, you will need to go much farther
beyond the passed vehicle before you can return to
your lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, just move that hand
to the left. To move the trailer to the right, move your
hand to the right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you are turning with a trailer, make wider turns
than normal. Do this so your trailer will not strike
soft shoulders, curbs, road signs, trees or other objects.
Avoid jerky or sudden maneuvers. Signal well in
advance.
4-38

Turn Signals When Towing a Trailer
When you tow a trailer, your vehicle may need a
different turn signal asher and/or extra wiring. Check
with your dealer/retailer. The arrows on your instrument
panel will ash whenever you signal a turn or lane
change. Properly hooked up, the trailer lamps will also
ash, telling other drivers you are about to turn,
change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It
is important to check occasionally to be sure the trailer
bulbs are still working.
Your vehicle has bulb warning lights. When you plug a
trailer lighting system into your vehicle’s lighting
system, its bulb warning lights may not let you know if
one of your lamps goes out. So, when you have a trailer
lighting system plugged in, be sure to check your
vehicle and trailer lamps from time to time to be sure
they are all working. Once you disconnect the trailer
lamps, the bulb warning lights again can tell you if one
of your vehicle lamps is out.
Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you do not shift down,
you might have to use your brakes so much that they
would get hot and no longer work well.
On a long uphill grade, shift down to THIRD (3) and
reduce your speed to around 45 mph (70 km/h) to reduce
the possibility of engine and transmission overheating.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People can
be injured, and both your vehicle and the trailer
can be damaged.
But if you ever have to park your rig on a hill, here is how
to do it:
1. Apply your regular brakes, but do not shift into
PARK (P) yet.
2. Have someone place chocks under the trailer
wheels.
4-39

3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake, and then shift to PARK (P).
5. Release the regular brakes.
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
Start your 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
Your vehicle will need service more often when you’re
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission uid (don’t overll),
engine oil, drive belt, cooling system and brake
system. Each of these is covered in this manual, and
the Index will help you nd them quickly. If you’re
trailering, it’s a good idea to review this information
before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Engine Cooling When Trailer Towing
Your cooling system may temporarily overheat during
severe operating conditions. SeeEngine Overheating on
page 5-29.
Towing a Trailer (Vehicles Without
Heavy Duty Cooling)
Vehicles without heavy duty cooling are neither designed
nor intended to tow a trailer.
4-40

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-3
California Perchlorate Materials Requirements.....5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside
of Your Vehicle...........................................5-4
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-11
Engine Oil...................................................5-18
Engine Oil Life System..................................5-21
Engine Air Cleaner/Filter................................5-23
Automatic Transmission Fluid.........................5-25
Engine Coolant.............................................5-25
Coolant Surge Tank Pressure Cap..................5-29
Engine Overheating.......................................5-29
Overheated Engine Protection Operating Mode . . .5-31Cooling System............................................5-32
Power Steering Fluid.....................................5-39
Windshield Washer Fluid................................5-40
Brakes........................................................5-41
Battery........................................................5-44
Jump Starting...............................................5-45
All-Wheel Drive..............................................5-50
Rear Axle.......................................................5-51
Front Axle......................................................5-52
Headlamp Aiming...........................................5-53
Bulb Replacement..........................................5-54
High Intensity Discharge (HID) Lighting............5-54
Halogen Bulbs..............................................5-54
Back-Up Lamps............................................5-54
Replacement Bulbs.......................................5-55
Windshield Replacement.................................5-55
Windshield Wiper Blade Replacement..............5-55
Tires..............................................................5-57
Winter Tires.................................................5-58
Tire Sidewall Labeling...................................5-59
Tire Terminology and Denitions.....................5-62
Run-Flat Tires (STS-V)..................................5-65
Ination - Tire Pressure.................................5-66
High-Speed Operation...................................5-68
Section 5 Service and Appearance Care
5-1

Tire Pressure Monitor System.........................5-68
Tire Pressure Monitor Operation.....................5-70
Tire Inspection and Rotation...........................5-73
When It Is Time for New Tires.......................5-75
Buying New Tires.........................................5-76
Different Size Tires and Wheels......................5-78
Uniform Tire Quality Grading..........................5-79
Wheel Alignment and Tire Balance..................5-80
Wheel Replacement......................................5-80
Tire Chains..................................................5-82
Lifting Your Vehicle (STS-V)...........................5-83
If a Tire Goes Flat........................................5-86
Tire Sealant and Compressor Kit....................5-87
Changing a Flat Tire.....................................5-96
Removing the Spare Tire and Tools................5-98
Removing the Flat Tire and Installing
the Spare Tire..........................................5-99
Storing a Flat or Spare Tire and Tools...........5-104
Compact Spare Tire....................................5-106
Appearance Care..........................................5-107
Interior Cleaning.........................................5-107
Fabric/Carpet..............................................5-108
Leather......................................................5-109
Instrument Panel, Vinyl, and Other
Plastic Surfaces.......................................5-109
Wood Panels..............................................5-110Speaker Covers..........................................5-110
Care of Safety Belts....................................5-110
Weatherstrips.............................................5-110
Washing Your Vehicle..................................5-110
Cleaning Exterior Lamps/Lenses....................5-111
Finish Care................................................5-111
Windshield and Wiper Blades.......................5-112
Aluminum or Chrome-Plated Wheels and Trim . . .5-112
Tires.........................................................5-113
Sheet Metal Damage...................................5-113
Finish Damage...........................................5-114
Underbody Maintenance...............................5-114
Chemical Paint Spotting...............................5-114
Vehicle Care/Appearance Materials................5-115
Vehicle Identication.....................................5-116
Vehicle Identication Number (VIN)................5-116
Service Parts Identication Label...................5-116
Electrical System..........................................5-116
Add-On Electrical Equipment.........................5-116
Headlamp Wiring........................................5-117
Windshield Wiper Fuses...............................5-117
Power Windows and Other Power Options......5-117
Fuses and Circuit Breakers..........................5-117
Underhood Fuse Block................................5-118
Rear Underseat Fuse Block..........................5-121
Capacities and Specications........................5-128
Section 5 Service and Appearance Care
5-2