2009 CADILLAC DTS check engine light

{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.
Open a window about two inches (5 cm) 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.
CAUTION: (Continued)
CAUTION: (Continued)
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.
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.
4-17

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

Engine Overheating
The vehicle has several indicators to warn of engine
overheating.
There is an engine temperature warning light and/or
gage on the instrument panel cluster. SeeEngine
Coolant Temperature Warning Light on page 3-59and
Engine Coolant Temperature Gage on page 3-60.
The vehicle may also display a ENGINE OVERHEATED
IDLE ENGINE message or an ENGINE OVERHEATED
STOP ENGINE message displayed in the Driver
Information Center (DIC). SeeDIC Warnings and
Messages on page 3-73for more information. You will
also hear a chime.
You may decide not to lift the hood when this warning
appears, but instead get service help right away.
SeeRoadside Service on page 7-7.If you do decide to lift the hood, make sure the vehicle
is parked on a level surface.
Then check to see if the engine cooling fans are
running. If the engine is overheating, both fans should
be running. If they are not, do not continue to run
the engine and have the vehicle serviced.
Notice:Engine damage from running the engine
without coolant is not covered by the warranty.
Notice:If the engine catches re while driving with
no coolant, the vehicle can be badly damaged.
The costly repairs would not be covered by
the vehicle warranty. SeeOverheated Engine
Protection Operating Mode on page 5-30for
information on driving to a safe place in an
emergency.
5-28

The vehicle has an airbag system. Before attempting to
add anything electrical to the vehicle, seeServicing
Your Airbag-Equipped Vehicle on page 1-68.
Headlamp Wiring
The headlamp wiring system has four individual fuses. An
electrical overload will cause the lamps to go on and off,
or in some cases to remain off. If this happens, have the
headlamp wiring checked right away.
Windshield Wiper Fuses
The windshield wiper motor is protected by an internal
circuit breaker. If the wiper motor overheats due to
heavy snow, the wipers will stop until the motor cools
and will then restart.
A fuse powers the wiper motor. If the fuse blows, there
is an electrical problem. Be sure to have it xed.
Power Windows and Other Power
Options
Circuit breakers in the fuse block protect the power
windows and other power accessories. When the
current load is too heavy, the circuit breaker opens and
closes, protecting the circuit until the problem is xed or
goes away.
Fuses and Circuit Breakers
The wiring circuits in the vehicle are protected from
short circuits by a combination of fuses and circuit
breakers. This greatly reduces the chance of res
caused by electrical problems.
Look at the silver-colored band inside the fuse. If the
band is broken or melted, replace the fuse. Be sure you
replace a bad fuse with a new one of the identical size
and rating.
If you ever have a problem on the road and don’t have
a spare fuse, you can borrow one that has the same
amperage. Just pick some feature of the vehicle that you
can get along without — like the radio or cigarette
lighter — and use its fuse, if it is the correct amperage.
Replace it as soon as you can.
Underhood Fuse Block
The underhood fuse block is located on the passenger
side of the engine compartment. Remove the fuse cover
and secondary service cover to access the fuse block.
Notice:Spilling liquid on any electrical components
on the vehicle may damage it. Always keep the
covers on any electrical component.
5-95

Care of
Safety Belts................................................5-89
CD, MP3 .....................................................3-110
Center Console Storage...................................2-62
Center Flex Storage Unit.................................2-63
Center Seat...................................................1-10
Central Door Unlock System.............................2-11
Chains, Tire...................................................5-73
Charging System Light....................................3-56
Check
Engine Lamp..............................................3-61
Checking Things Under the Hood......................5-10
Chemical Paint Spotting...................................5-93
Child Restraints
Infants and Young Children...........................1-36
Lower Anchors and Tethers for Children..........1-43
Older Children.............................................1-33
Securing a Child Restraint in a
Rear Seat Position...................................1-49
Securing a Child Restraint in the
Center Front Seat Position........................1-51
Securing a Child Restraint in the
Right Front Seat Position..........................1-52
Systems.....................................................1-39
Where to Put the Restraint...........................1-42
Circuit Breakers..............................................5-95Cleaning
Aluminum or Chrome-Plated Wheels..............5-92
Exterior Lamps/Lenses.................................5-90
Fabric/Carpet..............................................5-87
Finish Care.................................................5-90
Instrument Panel, Vinyl, and Other
Plastic Surfaces.......................................5-88
Interior.......................................................5-86
Leather......................................................5-88
Speaker Covers..........................................5-89
Tires..........................................................5-93
Underbody Maintenance...............................5-93
Washing Your Vehicle...................................5-90
Weatherstrips
..............................................5-89
Windshield and Wiper Blades........................5-91
Wood Panels..............................................5-89
Climate Control System
Outlet Adjustment........................................3-46
Climate Control Systems
Dual ..........................................................3-40
Rear ..........................................................3-46
Clock............................................................3-39
Clock, Setting.................................................3-96
Collision Damage Repair..................................7-12
Compass...............................................1-11, 2-38
Content Theft-Deterrent....................................2-21
3

Driving (cont.)
Highway Hypnosis.......................................4-14
Hill and Mountain Roads..............................4-15
In Rain and on Wet Roads...........................4-12
Loss of Control...........................................4-10
Off-Road Recovery......................................4-10
Rocking Your Vehicle to Get it Out.................4-19
Winter........................................................4-16
Driving for Better Fuel Economy......................... 4-2
Dual Climate Control System............................3-40
E
EDR .............................................................7-17
Electrical Equipment
Add-On Equipment......................................5-94
Electrical System
Fuses and Circuit Breakers...........................5-95
Headlamp Wiring.........................................5-95
Power Windows and Other Power Options......5-95
Rear Underseat Fuse Block..........................5-98
Underhood Fuse Block.................................5-95
Windshield Wiper Fuses...............................5-95
Electronic Immobilizer
PASS-Key
®III+...........................................2-22Electronic Immobilizer Operation
PASS-Key
®III+...........................................2-23
Engine
Air Cleaner/Filter.........................................5-17
Check and Service Engine Soon Lamp...........3-61
Compartment Overview................................5-12
Coolant......................................................5-23
Coolant Heater............................................2-28
Coolant Temperature Gage...........................3-60
Coolant Temperature Warning Light................3-59
Cooling System...........................................5-22
Drive Belt Routing.......................................6-14
Exhaust.....................................................2-36
Oil .............................................................5-13
Oil Life System...........................................5-16
Overheated Protection Operating Mode...........5-30
Overheating................................................5-28
Starting......................................................2-26
Entry Lighting.................................................3-35
eporting Safety Defects to the
United States Government............................7-15
Event Data Recorders.....................................7-18
Extender, Safety Belt.......................................1-32
Exterior Lamps...............................................3-29
Exterior Lighting Battery Saver..........................3-34
5

H
Hazard Warning Flashers................................... 3-6
Head Restraints............................................... 1-2
Headlamp
Aiming .......................................................5-43
Headlamp Wiring............................................5-95
Headlamps
Bulb Replacement.......................................5-46
Daytime Running Lamps (DRL).....................3-33
Exterior Lamps............................................3-29
Flash-to-Pass..............................................3-13
High Intensity Discharge (HID) Lighting...........5-46
High/Low Beam Changer................................ 3-9
On Reminder..............................................3-33
Wiper Activated...........................................3-32
Heated
Steering Wheel............................................. 3-7
Heated Seats................................................... 1-5
Heater
Engine Coolant...........................................2-28
Highbeam On Light.........................................3-66
High-Speed Operation, Tires.............................5-59
Highway Hypnosis...........................................4-14Hill and Mountain Roads..................................4-15
Hood
Checking Things Under................................5-10
Release.....................................................5-11
Horn ............................................................... 3-6
How to Wear Safety Belts Properly...................1-17
I
Ignition Positions.............................................2-25
Inadvertent Power Battery Saver.......................3-37
Infants and Young Children, Restraints...............1-36
Ination - Tire Pressure...................................5-57
Instrument Panel
Brightness..................................................3-34
Cluster.......................................................3-51
Overview..................................................... 3-4
Introduction...................................................... 6-2
J
Jump Starting.................................................5-38
7