2009 CADILLAC DTS cooling

Footwell Lamps
For vehicles with footwell lamps, they are located
under the instrument panel and at the rear of the
front seats. These lamps provide soft light to the front
and rear oor areas. They dim with the instrument
panel cluster lights.
Footwell lighting brightness can be adjusted with the
instrument panel brightness control located below the
exterior lamps control. SeeInstrument Panel Brightness
on page 3-34. The footwell lights will turn off before
the instrument panel lights are at their lowest level of
brightness.
Battery Load Management
This feature monitors the vehicle’s electrical load and
determines when the battery is in a heavy discharge
condition. During times of high electrical loading, the
engine may idle at a higher revolutions per minute (rpm)
setting than normal to make sure the battery charges.
High electrical loads may occur when several of the
following are on: headlamps, high beams, fog lamps,
rear window defogger, the climate control fan at high
speeds, heated seats and engine cooling fans.If the battery continues to discharge, even with the
engine idling at a higher rpm setting, some electrical
loads will automatically be reduced. When this occurs,
the rear window defogger may take slightly longer
to clear the glass, the heated seats may not get as
warm as they usually do and the climate control fan
may cut back to a lower speed. For more battery
saving information, see “Battery Saver Active Message”
underDIC Warnings and Messages on page 3-73.
Electric Power Management
The vehicle has Electric Power Management (EPM) that
estimates the battery’s temperature and state of charge.
It then adjusts the voltage for best performance and
extended life of the battery.
When the battery’s state of charge is low, the voltage
is raised slightly to quickly bring the charge back up.
When the state of charge is high, the voltage is lowered
slightly to prevent overcharging. If the vehicle has a
voltmeter gage or a voltage display on the Driver
Information Center (DIC), you may see the voltage
move up or down. This is normal. If there is a problem,
an alert will be displayed.
3-36

The battery can be discharged at idle if the electrical
loads are very high. This is true for all vehicles.
This is because the generator (alternator) may not
be spinning fast enough at idle to produce all the
power that is needed for very high electrical loads.
A high electrical load occurs when several of the
following are on, such as: headlamps, high beams,
fog lamps, rear window defogger, climate control fan at
high speed, heated seats, engine cooling fans, trailer
loads, and loads plugged into accessory power outlets.
EPM works to prevent excessive discharge of the
battery. It does this by balancing the generator’s output
and the vehicle’s electrical needs. It can increase engine
idle speed to generate more power, whenever needed.
It can temporarily reduce the power demands of some
accessories.
Normally, these actions occur in steps or levels, without
being noticeable. In rare cases at the highest levels of
corrective action, this action may be noticeable to the
driver. If so, a Driver Information Center (DIC) message
might be displayed, such as BATTERY SAVER ACTIVE,
BATTERY VOLTAGE LOW, or LOW BATTERY. If this
message is displayed, it is recommended that the driver
reduce the electrical loads as much as possible. SeeDIC
Warnings and Messages on page 3-73.Inadvertent Power Battery Saver
This feature is designed to protect your vehicle’s battery
against drainage from the interior lamps, trunk lamp,
glove box lamp, or the garage door opener. When the
ignition is turned off, the power to these features will
automatically turn off after 10 minutes. Power will be
restored for an additional 10 minutes if any door or trunk
is opened, or the courtesy lamp switch is turned on.
Battery Run-Down Protection
This feature helps prevent the battery from being
drained, if the interior courtesy lamps, reading/map
lamps, visor vanity lamps or trunk lamp are accidentally
left on. If any of these lamps are left on, they
automatically turn off after 10 minutes, if the ignition
is off. The lamps will not come back on again until
one of the following occurs:
The ignition is turned on.
The exterior lamps control is turned off, then on
again.
The headlamps will time-out after 10 minutes, if they are
manually turned on with the ignition on or off.
3-37

Climate Controls
Dual Climate Control System
The heating, cooling, and ventilation for the vehicle can
be controlled with this system.
A. Fan Control
B. Display
C. Air Delivery Mode
Control
D. Driver and
Passenger
Temperature
ControlsE. Air Conditioning
F. Outside Air or AUX
G. Recirculation
H. PASS (Passenger
Climate Control)
I. Rear Window
Defogger Dual Climate Control System
Dual Climate Control System for Vehicles with
Rear Climate Control
3-40

Lane Departure Warning (LDW)
Light
For vehicles with the lane
departure warning system,
this light briey comes
on amber, while starting
the vehicle, to indicate
that it is working.
If it does not, have the vehicle serviced by your
dealer/retailer. If the system is working normally the
indicator light then goes off.
When driving at speeds of 35 mph (56 km) or greater
and LDW is turned on, a green warning symbol appears
when the system has detected lane markings on at
least one side of the vehicle.
For more information seeLane Departure Warning
(LDW) on page 2-49.When LDW is active, the amber warning symbol comes
on and ashes. Three beeps sound if a lane marking
is crossed without using the turn signal. If the warning
symbol is not on, LDW is not operating and will not
warn when the vehicle crosses a lane marking.
Engine Coolant Temperature
Warning Light
The engine coolant
temperature warning
light comes on when
the engine is very hot.
This light also comes 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 the vehicle to overheat, seeOverheated
Engine Protection Operating Mode on page 5-30.
SeeEngine Overheating on page 5-28andDIC Warnings
and Messages on page 3-73for more information.
3-59

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 comes on. SeeEngine Overheating on page 5-28
for more information.
Tire Pressure Light
For vehicles with a tire
pressure monitoring
system, this light comes
on briey when the engine
is started.
It provides information about tire pressures and the
Tire Pressure Monitoring System.
3-60

Hill and Mountain Roads
Driving on steep hills or through mountains is different
than driving on at or rolling terrain. Tips for driving
in these conditions include:
Keep the vehicle serviced and in good shape.
Check all uid levels and brakes, tires, cooling
system, and transmission.
Going down steep or long hills, shift to a
lower gear.
{CAUTION:
If you do not shift down, the brakes could get so
hot that they would not work well. You would then
have poor braking or even none going down a hill.
You could crash. Shift down to let the engine
assist the brakes on a steep downhill slope.
{CAUTION:
Coasting downhill in N (Neutral) or with the ignition
off is dangerous. The brakes will have to do all the
work of slowing down and they could get so hot
that they would not work well. You would then
have poor braking or even none going down a hill.
You could crash. Always have the engine running
and the vehicle in gear when going downhill.
Stay in your own lane. Do not swing wide or cut
across the center of the road. Drive at speeds
that let you stay in your own lane.
Top of hills: Be alert — something could be in your
lane (stalled car, accident).
Pay attention to special road signs (falling rocks
area, winding roads, long grades, passing or
no-passing zones) and take appropriate action.
4-15

Leaving After Parking on a Hill
1. Apply and hold the brake pedal while you:
start the engine,
shift into a gear, and
release the parking brake.
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
The vehicle needs service more often when pulling a
trailer. SeeScheduled Maintenance on page 6-4
for more information. Things that are especially
important in trailer operation are automatic transmission
uid, engine oil, belts, cooling system and brake
system. It is a good idea to inspect these before and
during the trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily overheat during
severe operating conditions. SeeEngine Overheating on
page 5-28.
Changing a Tire When Trailer Towing
If the vehicle gets a at tire while towing a trailer,
be sure to secure the trailer and disconnect it from the
vehicle before changing the tire.
4-34

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