2009 CADILLAC DTS check engine

Checking the Fluid Level
Prepare the vehicle as follows:
1. Park the vehicle on a level place. Keep the engine
running.
2. With the parking brake applied, place the shift lever
in P (Park).
3. With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position
the shift lever in P (Park).
4. Let the engine run at idle for three to ve minutes.
Then, without shutting off the engine, follow these steps:
1. Locate the transmission uid cap which is located
next to the radiator hose and below the engine air
cleaner/lter assembly on the driver side of the
vehicle. The cap is marked TRANS FLUID.
SeeEngine Compartment Overview on page 5-12
for more information on location.
2. After removing the engine air cleaner/lter assembly
to reach the transmission uid cap, turn the cap
counterclockwise to remove. Pull out the dipstick
and wipe it with a clean rag or paper towel.
3. Push it back in all the way, wait three seconds, and
then pull it back out again.4. Check both sides of the dipstick and read the
lower level. The uid level must be in the
cross-hatched area.
5. If the uid level is in the acceptable range, push
the dipstick back in all the way and turn the
handle clockwise.
6. Reinstall the engine air cleaner/lter assembly.
5-20

{CAUTION:
An electric engine cooling fan under the hood can
start up even when the engine is not running and
can cause injury. Keep hands, clothing, and tools
away from any underhood electric fan.
{CAUTION:
Heater and radiator hoses, and other engine parts,
can be very hot. Do not touch them. If you do, you
can be burned.
Do not run the engine if there is a leak. If you run
the engine, it could lose all coolant. That could
cause an engine re, and you could be burned.
Get any leak xed before you drive the vehicle.Notice:Using coolant other than DEX-COOL
®can
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant could
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by the vehicle warranty.
Always use DEX-COOL
®(silicate-free) coolant in the
vehicle.
Engine Coolant
The cooling system in the vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in the vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst.
The following explains the cooling system and how to
check and add coolant when it is low. If there is a
problem with engine overheating, seeEngine
Overheating on page 5-28.
5-23

Checking Coolant
The vehicle must be on a level surface when checking
the coolant level.
Check to see if coolant is visible in the coolant recovery
tank. If the coolant inside the coolant recovery tank is
boiling, do not do anything else until it cools down. If
coolant is visible but the coolant level is not at or above
the FULL COLD mark, add a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant at the coolant
recovery tank, but be sure the cooling system is cool
before this is done. SeeEngine Coolant on page 5-23for
more information.
How to Add Coolant to the Surge Tank
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn if the engine parts are hot enough.
Do not spill coolant on a hot engine.Notice:This vehicle has a specic coolant ll
procedure. Failure to follow this procedure could
cause the engine to overheat and be severely
damaged.
{CAUTION:
An electric engine cooling fan under the hood can
start up even when the engine is not running and
can cause injury. Keep hands, clothing, and tools
away from any underhood electric fan.
5-25

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

Power Steering Fluid
The power steering uid
reservoir is located next to
the underhood fuse block
on the passenger side of
the vehicle. SeeEngine
Compartment Overview
on page 5-12for more
information on location.
When to Check Power Steering Fluid
It is not necessary to regularly check power steering uid
unless you suspect there is a leak in the system or
you hear an unusual noise. A uid loss in this system
could indicate a problem. Have the system inspected
and repaired.
How to Check Power Steering Fluid
To check the power steering uid:
1. Turn the key off and let the engine compartment
cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a
clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the uid level on
the dipstick.
The level should be at the FULL COLD mark.
If necessary, add only enough uid to bring the
level up to the mark.
What to Use
To determine what kind of uid to use, see
Recommended Fluids and Lubricants on page 6-11.
Always use the proper uid.
Notice:Use of the incorrect uid may damage the
vehicle and the damages may not be covered by
the vehicle’s warranty. Always use the correct uid
listed inRecommended Fluids and Lubricants on
page 6-11.
5-31

{CAUTION:
Fans or other moving engine parts can injure you
badly. Keep your hands away from moving parts
once the engine is running.
5. Check that the jumper cables do not have loose or
missing insulation. If they do, you could get a
shock. The vehicles could be damaged too.
Before you connect the cables, here are some
basic things you should know. Positive (+) will go to
positive (+) or to a remote positive (+) terminal if the
vehicle has one. Negative (−) will go to a heavy,
unpainted metal engine part or to a remote
negative (−) terminal if the vehicle has one.
Do not connect positive (+) to negative (−)oryou
will get a short that would damage the battery
and maybe other parts too. And do not connect the
negative (−) cable to the negative (−) terminal on
the dead battery because this can cause sparks.
6. Connect the red positive (+) cable to the remote
positive (+) terminal location on the vehicle with
the dead battery. Use a remote positive (+) terminal
if the vehicle has one.7. Do not let the other end touch metal. Connect it to
the positive (+) terminal location of the vehicle with
the good battery. Use a remote positive (+) terminal if
the vehicle has one.
8. Now connect the black negative (−) cable to the
negative (−) terminal location of the vehicle with
the good battery. Use a remote negative (−) terminal
if the vehicle has one.
Do not let the other end of the cable touch anything
until the next step. The other end of the negative (−)
cable does not go to the dead battery. It goes to a
heavy, unpainted metal engine part or to a remote
negative (−) terminal on the vehicle with the dead
battery.
9. Connect the other end of the negative (−) cable to
the negative (−) terminal location on the vehicle
with the dead battery. Your vehicle has a remote
negative (−) terminal marked GND (−).
10. Now start the vehicle with the good battery and run
the engine for a while.
11. Try to start the vehicle that had the dead battery.
If it will not start after a few tries, it probably needs
service.
5-41

Vehicle Identication
Vehicle Identication Number (VIN)
This is the legal identier for the vehicle. It appears on a
plate in the front corner of the instrument panel, on the
driver side. It can be seen through the windshield from
outside the vehicle. The VIN also appears on the Vehicle
Certication and Service Parts labels and the certicates
of title and registration.
Engine Identication
The eighth character in the VIN is the engine code. This
code helps identify the vehicle’s engine, specications,
and replacement parts. See “Engine Specications”
underCapacities and Specifications on page 5-103for
the vehicle’s engine code.
Service Parts Identication Label
This label is on the spare tire cover. It is very helpful if
parts need to be ordered. The label has the following
information:
Vehicle Identication Number (VIN)
Model designation
Paint information
Production options and special equipment
Do not remove this label from the vehicle.
Electrical System
Add-On Electrical Equipment
Notice:Do not add anything electrical to the vehicle
unless you check with your dealer/retailer rst. Some
electrical equipment can damage the vehicle and
the damage would not be covered by the vehicle’s
warranty. Some add-on electrical equipment can
keep other components from working as they should.
Add-on equipment can drain the vehicle battery, even if
the vehicle is not operating.
5-94

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