2008 CADILLAC DTS overheating

Lane Departure Warning Light
Your vehicle may have the
lane departure warning
system.
This light will come on green, briey, when the vehicle
is started to show that it is working. This light will
also come on green if the system detects a left or
right lane marking. This light will change to amber
and ash and three beeps will sound if you cross a
detected lane marking without using your turn signal.
For more information, see the Index in the Navigation
Manual.
Engine Coolant Temperature
Warning Light
The engine coolant
temperature warning light
will come on when the
engine is very hot.
This light will also come on briey when the vehicle is
started.
If the light does not go out or comes on and stays on
while driving, there may be a problem with the cooling
system. Driving with engine coolant temperature light on
could cause your vehicle to overheat, seeOverheated
Engine Protection Operating Mode on page 5-29.
SeeEngine Overheating on page 5-27andDIC
Warnings and Messages on page 3-75for more
information.
3-63

Engine Coolant Temperature Gage
This gage shows the
engine coolant
temperature.
It indicates when the engine has warmed up and if
the cooling system is operating properly. If the gage
pointer moves into the shaded area, the engine coolant
is too hot and the engine coolant temperature warning
light will come on. SeeEngine Overheating on
page 5-27for more information.
Tire Pressure Light
This light comes on briey
when the engine is started.
This light will also come on when one or more of your
tires are signicantly underinated.
A tire pressure message in the Driver Information
Center (DIC), may accompany the light. SeeDIC
Warnings and Messages on page 3-75for more
information.
Stop and check your tires as soon as it is safe to
do so. If underinated, inate to the proper pressure.
SeeTires on page 5-52for more information.
If a problem is detected with the Tire Pressure Monitor
System, this light will ash for approximately 60 seconds
and then stay on solid for the remainder of the ignition
cycle. SeeTire Pressure Monitor System on page 5-63
for more information.
3-64

ENGINE HOT – A/C (Air
Conditioning) OFF
This message displays when the engine coolant
becomes hotter than the normal operating temperature.
SeeEngine Coolant Temperature Gage on page 3-64.
To avoid added strain on a hot engine, the air
conditioning compressor automatically turns off. When
the coolant temperature returns to normal, the air
conditioning compressor turns back on. You can
continue to drive your vehicle.
If this message continues to appear, have the system
repaired by your dealer/retailer as soon as possible
to avoid damage to the engine.
ENGINE OVERHEATED IDLE ENGINE
Notice:If you drive your vehicle while the engine
is overheating, severe engine damage may occur.
If an overheat warning appears on the instrument
panel cluster and/or DIC, stop the vehicle as soon
as possible. Do not increase the engine speed
above normal idling speed. SeeEngine Overheating
on page 5-27for more information.
This message displays when the engine coolant
temperature is too hot. Stop and allow the vehicle
to idle until it cools down. SeeEngine Coolant
Temperature Warning Light on page 3-63.SeeOverheated Engine Protection Operating Mode on
page 5-29for information on driving to a safe place
in an emergency.
ENGINE OVERHEATED STOP ENGINE
Notice:If you drive your vehicle while the engine
is overheating, severe engine damage may occur.
If an overheat warning appears on the instrument
panel cluster and/or DIC, stop the vehicle as soon as
possible. SeeEngine Overheating on page 5-27
for more information.
This message displays when the engine has overheated.
Immediately look for a safe place to pull your vehicle
over and turn the engine off right away to avoid severe
engine damage. SeeEngine Overheating on page 5-27
andOverheated Engine Protection Operating Mode
on page 5-29. A chime also sounds when this message
is displayed.
ENGINE POWER REDUCED
This message displays when the engine power is
being reduced to protect the engine from damage.
There could be several malfunctions that might cause
this message. Reduced engine power can affect
the vehicle’s ability to accelerate. If this message
is on, but there is no reduction in performance,
proceed to your destination. The performance may
be reduced the next time the vehicle is driven.
3-77

TIRE LEARNING ACTIVE
This message displays when the Tire Pressure Monitor
System (TPMS) is re-learning the tire positions on
your vehicle. The tire positions must be re-learned after
rotating the tires or after replacing a tire or sensor.
SeeTire Inspection and Rotation on page 5-68,
Tire Pressure Monitor System on page 5-63, and
Inflation - Tire Pressure on page 5-60for more
information.
TRACTION CONTROL OFF
This message displays when the Traction Control
System (TCS) is turned off. Adjust your driving
accordingly. SeeTraction Control System (TCS) on
page 4-5for more information.
TRACTION CONTROL ON
This message displays when the Traction Control
System (TCS) is turned on. SeeTraction Control
System (TCS) on page 4-5for more information.
TRANSMISSION HOT IDLE ENGINE
Notice:If you drive your vehicle while the
transmission uid is overheating and the
transmission temperature warning is displayed
on the instrument panel cluster and/or DIC, you
can damage the transmission. This could lead
to costly repairs that would not be covered by your
warranty. Do not drive your vehicle with overheated
transmission uid or while the transmission
temperature warning is displayed.
This message displays when the transmission uid in
your vehicle is too hot. Stop the vehicle and allow
it to idle until the transmission cools down or until this
message is removed.
TRUNK OPEN
This symbol appears with
this message.
This message displays when the trunk is not closed
completely. Make sure that the trunk is closed
completely.
3-86

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 gearbeforeyou 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.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if you ever have to park your rig on a hill, here is
how to do it:
1. Apply your regular brakes, but do not shift into
PARK (P).
2. Have someone place chocks behind the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then shift into
PARK (P) rmly and apply your parking brake.
5. Release the regular brakes.
4-32

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 5-27.
4-33

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...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-11
Checking Things Under the Hood....................5-12
Hood Release..............................................5-12
Engine Compartment Overview.......................5-14
Engine Oil...................................................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter................................5-20
Automatic Transmission Fluid.........................5-21
Engine Coolant.............................................5-24
Coolant Surge Tank Pressure Cap..................5-27Engine Overheating.......................................5-27
Overheated Engine Protection
Operating Mode........................................5-29
Cooling System............................................5-30
Power Steering Fluid.....................................5-35
Windshield Washer Fluid................................5-36
Brakes........................................................5-37
Battery........................................................5-40
Jump Starting...............................................5-42
Headlamp Aiming...........................................5-47
Bulb Replacement..........................................5-50
High Intensity Discharge (HID) Lighting..............5-50
Windshield Wiper Blade Replacement..............5-50
Tires..............................................................5-52
Tire Sidewall Labeling...................................5-53
Tire Terminology and Denitions.....................5-57
Ination - Tire Pressure.................................5-60
High-Speed Operation...................................5-62
Tire Pressure Monitor System.........................5-63
Tire Pressure Monitor Operation.....................5-64
Tire Inspection and Rotation...........................5-68
When It Is Time for New Tires.......................5-70
Buying New Tires.........................................5-71
Different Size Tires and Wheels......................5-73
Section 5 Service and Appearance Care
5-1

How to Add Automatic Transmission
Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission uid to use. SeeRecommended
Fluids and Lubricants on page 6-13.
If the uid level is low, add only enough of the proper
uid to bring the level into the cross-hatched area on
the dipstick.
1. Pull out the dipstick.
2. Using a long-neck funnel, add enough uid at the
dipstick hole to bring it to the proper level.
It does not take much uid, generally less than
one pint (0.5 L). Do not overll.
Notice:Use of the incorrect automatic transmission
uid may damage your vehicle, and the damages
may not be covered by your warranty. Always
use the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-13.
3. After adding uid, recheck the uid level as
described under “How to Check Automatic
Transmission Fluid,” earlier in this section.
4. When the correct uid level is obtained, push the
dipstick back in all the way and turn the handle
clockwise.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended life coolant.
The following explains your cooling system and how
to add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating
on page 5-27.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Giving freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®can
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at the rst maintenance
service after each 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.
5-24