2008 CADILLAC STS coolant temperature

Engine Coolant Heater
The engine coolant heater, if available, can help in cold
weather conditions at or below 0°F (−18°C) for easier
starting and better fuel economy during engine warm-up.
Plug in the coolant heater at least four hours before
starting your vehicle. An internal thermostat in the
plug-end of the cord may exist which will prevent
engine coolant heater operation at temperatures
above 0°F (−18°C).
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
For the 3.6L V6 and 4.4L V8 engine, the cord is
located in the front of the engine compartment,
on the passenger’s side of the vehicle.
For the 4.6L V8 engine, the cord is located in the
engine compartment on the driver’s side of the
vehicle near the inner fender and above the strut.
3. You must remove the plastic cap to access the plug.
4. Plug it into a normal, grounded 110-volt AC outlet.
{CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the
wrong kind of extension cord could overheat
and cause a re. You could be seriously
injured. Plug the cord into a properly grounded
three-prong 110-volt AC outlet. If the cord will
not reach, use a heavy-duty three-prong
extension cord rated for at least 15 amps.
5. Before starting the engine, be sure to unplug and
store the cord as it was before to keep it away
from moving engine parts. If you do not, it could be
damaged.
How long should you keep the coolant heater plugged
in? The answer depends on the outside temperature, the
kind of oil you have, and some other things. Instead
of trying to list everything here, we ask that you contact
your dealer in the area where you will be parking
your vehicle. The dealer can give you the best advice
for that particular area.
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Warning Lights, Gages, and Indicators............3-57
Instrument Panel Cluster................................3-58
Speedometer and Odometer...........................3-59
Tachometer.................................................3-59
Safety Belt Reminders...................................3-59
Airbag Readiness Light..................................3-60
Passenger Airbag Status Indicator...................3-61
Charging System Light..................................3-63
Brake System Warning Light..........................3-64
Antilock Brake System Warning Light...............3-65
Traction Control System (TCS)
Warning Light...........................................3-65
Lane Departure Warning Light........................3-66
Engine Coolant Temperature Warning Light......3-66
Engine Coolant Temperature Gage..................3-67
Tire Pressure Light.......................................3-67
Malfunction Indicator Lamp.............................3-68
Oil Pressure Light.........................................3-70
Security Light...............................................3-71
Fog Lamp Light............................................3-72
Lights On Reminder......................................3-72Cruise Control Light......................................3-72
Highbeam On Light.......................................3-72
Fuel Gage...................................................3-73
Driver Information Center (DIC).......................3-74
DIC Operation and Displays...........................3-74
DIC Warnings and Messages.........................3-80
Other Messages...........................................3-97
Audio System(s).............................................3-98
Setting the Time...........................................3-99
Radio(s) (MP3)...........................................3-100
Using an MP3............................................3-112
XM Radio Messages...................................3-116
Navigation/Radio System..............................3-117
Radio Personalization
..................................3-117
Theft-Deterrent Feature................................3-121
Audio Steering Wheel Controls......................3-121
Radio Reception.........................................3-123
Backglass Antenna......................................3-124
XM™ Satellite Radio Antenna System............3-124
Section 3 Instrument Panel
3-2

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, see
Overheated Engine Protection Operating Mode on
page 5-31. SeeEngine Overheating on page 5-29
andDIC Warnings and Messages on page 3-80for
more information.
3-66

Engine Coolant Temperature Gage
This gage shows the
engine coolant
temperature.
It can be used to see when your engine has warmed up
and to make sure your 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 5-29for 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 3-80for 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 5-57for 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 5-68
for more information.
3-67

ENGINE COOLANT HOT 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 5-29for more information.
This symbol appears
with this message.
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 3-66.
SeeOverheated Engine Protection Operating Mode
on page 5-31for information on driving to a safe
place in an emergency.
ENGINE HOT – AC
(Air Conditioning) OFF
This message displays when the engine coolant
becomes hotter than the normal operating temperature.
SeeEngine Coolant Temperature Gage on page 3-67.
To avoid added strain on a hot engine, the air
conditioning compressor is automatically turned 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 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 5-29
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 5-29
andOverheated Engine Protection Operating Mode
on page 5-31. A chime also sounds when this message
is displayed.
3-85

Automatic Transmission Fluid
How to Check Automatic
Transmission Fluid
It is not necessary to check the transmission uid level.
A transmission uid leak is the only reason for uid
loss. If a leak occurs, take the vehicle to the
dealer/retailer service department and have it repaired
as soon as possible.
There is a special procedure for checking and changing
the transmission uid. Because this procedure is
difficult, you should have this done at the dealership
service department. Contact your dealer for additional
information or the procedure can be found in the service
manual. To purchase a service manual, seeService
Publications Ordering Information on page 7-15.
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.
Change the uid and lter at the intervals listed in
Additional Required Services on page 6-6, and be sure
to use the uid listed inRecommended Fluids and
Lubricants on page 6-13.
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 5-29.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give 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
®may
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 your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
5-25

{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.
When replacing a pressure cap, make sure it is
hand-tight and fully seated.
Coolant Surge Tank Pressure Cap
Notice:If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. SeeEngine
Compartment Overview on page 5-11for more
information on location.
Engine Overheating
There are two engine hot messages that could be
displayed in the Driver Information Center (DIC).
SeeDIC Warnings and Messages on page 3-80for
more information.
If the engine is overheating, then you will nd a
coolant temperature gage and a coolant warning light
on the instrument panel. SeeEngine Coolant
Temperature Gage on page 3-67andEngine Coolant
Temperature Warning Light on page 3-66for more
information.
5-29

If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in NEUTRAL (N)
while stopped. If it is safe to do so, pull off the road,
shift to PARK (P) or NEUTRAL (N) and let the
engine idle.
2. Set the climate controls to the highest heat setting
and fan speed and open the windows, as
necessary.
If the coolant warning light is not on or the coolant
temperature gage does not indicate the engine
is overheating, you can drive. Just to be safe, drive
slower for about 10 minutes. If the warnings do not come
back on, drive normally.
If the warnings continue and you have not stopped, pull
over, stop, and park the vehicle right away.
If there is still no sign of steam, idle the engine for three
minutes while parked. If the warnings are still indicated,
turn off the engine and get everyone out of the
vehicle until it cools down. Also, see “Overheated
Engine Protection Operating Mode” later in this section.
You might decide not to lift the hood but to get
service help right away.Overheated Engine Protection
Operating Mode
This operating mode allows your vehicle to be driven
to a safe place in an emergency. Should an overheated
engine condition exist, an overheat protection mode
which alternates ring groups of cylinders helps prevent
engine damage. In this mode, you will notice a loss
in power and engine performance. An engine overheat
warning will indicate that an overheat condition
exists. Driving extended miles (km) and/or towing a
trailer in the overheat protection mode should be
avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any
repair. The engine oil will be severely degraded.
Repair the cause of coolant loss and change the oil.
SeeEngine Oil on page 5-18.
5-31