2009 CADILLAC DTS check engine

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....................................5-5
California Fuel...............................................5-5
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..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-13
Engine Oil Life System..................................5-16
Engine Air Cleaner/Filter................................5-17
Automatic Transmission Fluid.........................5-19
Cooling System............................................5-22
Engine Coolant.............................................5-23
Coolant Surge Tank Pressure Cap..................5-27
Engine Overheating.......................................5-28Overheated Engine Protection
Operating Mode........................................5-30
Power Steering Fluid.....................................5-31
Windshield Washer Fluid................................5-32
Brakes........................................................5-33
Battery........................................................5-36
Jump Starting...............................................5-38
Headlamp Aiming...........................................5-43
Bulb Replacement..........................................5-46
High Intensity Discharge (HID) Lighting............5-46
Windshield Wiper Blade Replacement..............5-46
Tires..............................................................5-48
Tire Sidewall Labeling...................................5-49
Tire Terminology and Denitions.....................5-54
Ination - Tire Pressure.................................5-57
High-Speed Operation...................................5-59
Tire Pressure Monitor System.........................5-60
Tire Pressure Monitor Operation.....................5-61
Tire Inspection and Rotation...........................5-65
When It Is Time for New Tires.......................5-67
Buying New Tires.........................................5-68
Different Size Tires and Wheels......................5-69
Uniform Tire Quality Grading..........................5-70
Wheel Alignment and Tire Balance..................5-71
Wheel Replacement......................................5-71
Section 5 Service and Appearance Care
5-1

Keep a record with all parts receipts and list the mileage
and the date of any service work performed. See
Maintenance Record on page 6-15.
Adding Equipment to the Outside of
the Vehicle
Things added to the outside of the vehicle can affect the
airow around it. This can cause wind noise and can
affect fuel economy and windshield washer performance.
Check with your dealer/retailer before adding equipment
to the outside of the vehicle.
Fuel
Use of the recommended fuel is an important part of the
proper maintenance of this vehicle. To help keep the
engine clean and maintain optimum vehicle performance,
we recommend the use of gasoline advertised as TOP
TIER Detergent Gasoline.
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 the vehicle’s
acceleration could be slightly reduced, and you mightnotice 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 or
3.511 in Canada. Some gasolines contain an
octane-enhancing additive called methylcyclopentadienyl
manganese tricarbonyl (MMT). We recommend
against the use of gasolines containing MMT. See
Additives on page 5-6for additional information.
California Fuel
If the 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, the vehicle will operate
satisfactorily on fuels meeting federal specications, but
emission control system performance might be affected.
5-5

The malfunction indicator lamp could turn on and the
vehicle might fail a smog-check test. SeeMalfunction
Indicator Lamp on page 3-61. If this occurs, return to your
authorized dealer/retailer for diagnosis. If it is determined
that the condition is caused by the type of fuel used,
repairs might not be covered by the vehicle warranty.
Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that help prevent
engine and fuel system deposits from forming, allowing
the emission control system to work properly. In most
cases, you should not have to add anything to the 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 the vehicle experiences
problems due to dirty injectors or valves, look for gasoline
that is advertised as TOP TIER Detergent Gasoline.
For customers who do not use TOP TIER Detergent
Gasoline regularly, one bottle of GM Fuel System
Treatment PLUS, added to the fuel tank at every engine
oil change, can help clean deposits from fuel injectors
and intake valves. GM Fuel System Treatment PLUS is
the only gasoline additive recommended by General
Motors.Also, your dealer/retailer has additives that will help
correct and prevent most deposit-related problems.
Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines might be available in
your area. We recommend 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:This 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 the vehicle
warranty.
Some gasolines that are not reformulated for low
emissions can contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. We recommend against
the use of such gasolines. Fuels containing MMT can
reduce the life of spark plugs and the performance of
the emission control system could be affected. The
malfunction indicator lamp might turn on. If this occurs,
return to your dealer/retailer for service.
5-6

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 the vehicle 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 the engine when you are
refueling. Do not smoke if you are near fuel or
refueling the vehicle. Do not use cellular phones.
CAUTION: (Continued)
CAUTION: (Continued)
Keep sparks, ames, and smoking materials away
from fuel. Do not leave the fuel pump unattended
when refueling the 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.
The tethered fuel cap is located behind a hinged fuel
door on the driver side of the vehicle.
5-7

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.
5-10

A.Underhood Fuse Block on page 5-95.
B. Remote Positive (+) Terminal. SeeJump Starting on
page 5-38.
C. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-32.
D. Engine Coolant Surge Tank and Pressure Cap.
SeeEngine Coolant on page 5-23.
E. Remote Negative (−) Terminal. SeeJump Starting
on page 5-38.
F.Power Steering Fluid on page 5-31.
G. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-13.
H. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-13.
I. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-33.
J. Automatic Transmission Fluid Cap and Dipstick
(Out of View). SeeAutomatic Transmission Fluid on
page 5-19.
K.Engine Air Cleaner/Filter on page 5-17.Engine Oil
Checking Engine Oil
It is a good idea to check the engine oil level at each
fuel ll. 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. See
Engine Compartment Overview on page 5-12for
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 this is not done, 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.
5-13

Engine Oil Additives / Engine Oil
Flushes
Do not add anything to the oil. The recommended oils
with the starburst symbol that meet GM standards are
all that is needed for good performance and engine
protection.
Engine oil system ushes are not recommended and
could cause engine damage not covered by the vehicle
warranty.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system that indicates when
to change the engine oil and lter. This is based on
engine revolutions and engine temperature, and not on
mileage. Based on driving conditions, the mileage at
which an oil change is indicated can vary considerably.
For the oil life system to work properly, the system
must be reset every time the oil is changed.When the system has calculated that oil life has been
diminished, it indicates that an oil change is necessary.
A CHANGE ENGINE OIL SOON message in the Driver
Information Center (DIC) comes on. Change the oil as
soon as possible within the next 600 miles (1 000 km).
It is possible that, if driving under the best conditions, the
oil life system might not indicate that an oil change is
necessary for over a year. However, the engine oil and
lter must be changed at least once a year and at this
time the system must be reset. Your dealer/retailer has
trained people who will perform this work using genuine
parts and reset the system. It is also important to check
the oil regularly and keep it at the proper level.
If the system is ever reset accidentally, the oil must be
changed at 3,000 miles (5 000 km) since the last oil
change. Remember to reset the oil life system whenever
the oil is changed.
5-16

Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
A good time to check the automatic transmission uid
level is when the engine oil is changed.
Change the uid and lter at the intervals listed in
Additional Required Services on page 6-5, and be sure
to use the transmission uid listed inRecommended
Fluids and Lubricants on page 6-11.
How to Check Automatic Transmission
Fluid
Because this operation can be a little difficult, you may
choose to have this done at the dealer/retailer service
department.
If you do it yourself, be sure to follow all the instructions
here or you could get a false reading on the dipstick.Notice:Too much or too little uid can damage
your transmission. Too much can mean that some
of the uid could come out and fall on hot engine
parts or exhaust system parts, starting a re.
Too little uid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission uid.
Wait at least 30 minutes before checking the
transmission uid level if you have been driving:
When outside temperatures are above 90°F (32°C).
At high speed for quite a while.
In heavy traffic — especially in hot weather.
While pulling a trailer.
To get the right reading, the uid should be at normal
operating temperature, which is 180°F to 200°F
(82°C to 93°C).
Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above 50°F
(10°C). If it is colder than 50°F (10°C), you may have
to drive longer.
5-19