2007 CADILLAC DTS PROFESSIONAL check engine

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.
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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

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.
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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

Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel might be
hard to nd. Never use leaded gasoline or any other
fuel not recommended in the previous text on fuel.
Costly repairs caused by use of improper fuel would
not be covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business
in the country where you will be driving.
Filling the Tank
{CAUTION:
Fuel vapor burns violently and a fuel re
can cause bad injuries. To help avoid
injuries to you and others, read and follow
all the instructions on the pump island.
Turn off your engine when you are
refueling. Do not smoke if you are near
fuel or refueling your vehicle. Do not use
cellular phones. Keep sparks, ames, and
smoking materials away from fuel. Do not
leave the fuel pump unattended when
refueling your vehicle. This is against the
law in some places. Do not re-enter the
vehicle while pumping fuel. Keep children
away from the fuel pump; never let
children pump fuel.
358

Checking Things Under
the Hood
{CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing, and tools
away from any underhood electric fan.
{CAUTION:
Things that burn can get on hot engine
parts and start a re. These include
liquids like fuel, oil, coolant, brake uid,
windshield washer and other uids, and
plastic or rubber. You or others could be
burned. Be careful not to drop or spill
things that will burn onto a hot engine.
362

A. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 452.
B. Remote Positive (+) Terminal. SeeJump
Starting on page 392.
C. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 386.
D. Engine Coolant Surge Tank and Pressure Cap.
SeeCoolant Surge Tank Pressure Cap on
page 377andCooling System on page 380.
E. Remote Negative (−) Terminal. SeeJump
Starting on page 392Jump Starting.
F. Power Steering Fluid. SeePower Steering
Fluid on page 385.
G. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil on page 365.
H. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 365.
I. Brake Master Cylinder Reservoir. See “Brake
Fluid” underBrakes on page 387.
J. Automatic Transaxle Fluid Cap and Dipstick
(Out of View). SeeAutomatic Transaxle
Fluid on page 372.
K. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 370.Engine Oil
Checking Engine Oil
It is a good idea to check the engine oil every time
you get fuel. In order to get an accurate reading,
the oil must be warm and the vehicle must be
on level ground.
The engine oil dipstick handle is a yellow loop.
SeeEngine Compartment Overview on page 364
for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several
minutes to drain back into the oil pan. If you
do not do this, the oil dipstick might not
show the actual level.
2. Pull out the dipstick and clean it with a paper
towel or cloth, then push it back in all the
way. Remove it again, keeping the tip down,
and check the level.
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