engine CADILLAC DTS PROFESSIONAL 2007 1.G Repair Manual

Towing a Trailer
The Cadillac Professional Vehicle cannot tow
a trailer.
{CAUTION:
If you do not use the correct equipment
and drive properly, you can lose control
when you pull a trailer. For example, if the
trailer is too heavy, the brakes may not
work well — or even at all. You and your
passengers could be seriously injured.
You may also damage your vehicle; the
resulting repairs would not be covered by
your warranty. Pull a trailer only if you
have followed all the steps in this section.
Ask your dealer/retailer for advice and
information about towing a trailer with
your vehicle.Your vehicle can tow a trailer if it is equipped with
the proper trailer towing equipment. To identify
the trailering capacity of your vehicle, you should
read the information in “Weight of the Trailer”
that appears later in this section. Trailering
is different than just driving your vehicle by itself.
Trailering means changes in handling, durability
and fuel economy. Successful, safe trailering takes
correct equipment, and it has to be used properly.
That is the reason for this part. In it are 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 you pull a trailer.
Load-pulling components such as the engine,
transmission, 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. What is more, the
trailer adds considerably to wind resistance,
increasing the pulling requirements.
342

If You Do Decide To Pull a Trailer
If you do, here are some important points:
There are many different laws, including speed
limit restrictions, having to do with trailering.
Make sure your rig will be legal, not only where
you live but also where you will be driving.
A good source for this information can be state
or provincial police.
Consider using a sway control. You can ask a
hitch dealer/retailer about sway controls.
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
(454 kg). These are total maximum weights
including the load. 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.
343

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 and Loading Information Label. See
Loading Your Vehicle on page 333. Then be sure
you do not go over the GVW limit for your vehicle,
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 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 130. Dirt
and water can, too.
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
Because your vehicle has anti-lock brakes, do not
try to tap into your vehicle’s hydraulic brake
system. If you do, both brake systems will not
work well, or at all.
Be sure to read and follow the instructions for the
trailer brakes so you will be able to maintain
them properly.
345

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.
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 /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.
Driving on Grades
Reduce speed and shift to a lower gearbefore
you 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 and reduce
your speed to around 45 mph (70 km/h) to reduce
the possibility of the engine and the transmission
overheating.
347

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, and
Make sure the parking brake has released.
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 are pulling a trailer. See the Maintenance
Schedule for more on this. Things that are
especially important in trailer operation are
automatic transmission uid (do not 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 are trailering, it is 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 377.
349

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

California Proposition 65 Warning
Most motor vehicles, including this one, contain
and/or emit chemicals known to the State of
California to cause cancer and birth defects or other
reproductive harm. Engine exhaust, many parts and
systems (including some inside the vehicle), many
uids, and some component wear by-products
contain and/or emit these chemicals.
Doing Your Own Service Work
{CAUTION:
You can be injured and your vehicle could
be damaged if you try to do service work
on a vehicle without knowing enough
about it.
Be sure you have sufficient knowledge,
experience, the proper replacement
parts, and tools before you attempt any
vehicle maintenance task.
Be sure to use the proper nuts, bolts,
and other fasteners. English and metric
fasteners can be easily confused. If you
use the wrong fasteners, parts can later
break or fall off. You could be hurt.
354

If you want to do some of your own service work,
you should use the proper service manual. It
tells you much more about how to service your
vehicle than this manual can. To order the proper
service manual, seeService Publications
Ordering Information on page 498.
Your vehicle has an airbag system. Before
attempting to do your own service work, see
Servicing Your Airbag-Equipped Vehicle on
page 86.
You should keep a record with all parts receipts
and list the mileage and the date of any service
work you perform. SeeMaintenance Record
on page 478.Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your
vehicle can affect the airow around it. This may
cause wind noise and affect windshield washer
performance. Check with your dealer before
adding equipment to the outside of your vehicle.
Fuel
Use of the recommended fuel is an important
part of the proper maintenance of your vehicle.
To help keep the engine clean and maintain
optimum vehicle performance, GM recommends
the use of gasoline advertised as TOP TIER
Detergent Gasoline.
355

Gasoline Octane
Use premium unleaded gasoline with a posted
octane rating of 91 or higher. You can also use
regular unleaded gasoline rated at 87 octane or
higher, but your vehicle’s acceleration could be
slightly reduced, and you might notice a slight
audible knocking noise, commonly referred to as
spark knock. If the octane is less than 87, you might
notice a heavy knocking noise when you drive. If
this occurs, use a gasoline rated at 87 octane or
higher as soon as possible. Otherwise, you could
damage the engine. If you are using gasoline rated
at 87 octane or higher and you hear heavy
knocking, the 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 357for 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 234. 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.
356

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.
To help keep fuel injectors and intake valves clean,
or if your vehicle experiences problems due to
dirty injectors or valves, look for gasoline that is
advertised as TOP TIER Detergent Gasoline. Also,
your dealer has additives that will help correct
and prevent most deposit-related problems.
Gasolines containing oxygenates, such as
ethers and ethanol, and reformulated gasolines
may be available in your area. General Motors
recommends that you use these gasolines if they
comply with the specications described earlier.However, E85 (85% ethanol) and other fuels
containing more than 10% ethanol must not be
used in vehicles that were not designed for
those fuels.
Notice:Your vehicle was not designed for
fuel that contains methanol. Do not use
fuel containing methanol. It can corrode metal
parts in the fuel system and also damage
plastic and rubber parts. That damage would
not be covered under your warranty.
Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT); ask the attendant where you
buy gasoline whether the fuel contains MMT.
General Motors recommends against the use of
such gasolines. Fuels containing MMT can reduce
the life of spark plugs and the performance of
the emission control system may be affected. The
malfunction indicator lamp may turn on. If this
occurs, return to your dealer for service.
357