engine coolant CHEVROLET CORVETTE 1999 5.G User Guide

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HIGH TRANS TEMP (Automatic Transmission
Only): You will hear four chimes when this message
is displayed. To acknowledge this warning, press the
RESET button. After you press the RESET button,
the message will be displayed every 10 minutes until the
condition changes. If you do not press RESET,
the message remains on the display until the
condition changes.
If the transmission fluid temperature rises above
270
F (132
C) or rises rapidly, this message is
displayed. The transmission may shift gears or apply the
torque converter clutch to reduce the fluid temperature.
Driving aggressively or driving on long hills can cause
the transmission fluid temperature to be higher than
normal. If this message appears, you may continue to
drive at a slower speed. You should also monitor the
transmission fluid temperature and allow it to cool to at
least 230
F (110
C). The transmission fluid temperature
can be monitored with the GAGES button on the DIC.
See ªAutomatic Transmission Fluidº in the Index.
You should also check the engine coolant temperature.
If it is also hot, see ªEngine Overheatingº in the Index.If the HIGH TRANS TEMP message is displayed
during normal vehicle operation on flat roads,
your vehicle may need service. See your dealer for
an inspection.
SERVICE ACTIVE HANDLING: If the SERVICE
ACTIVE HNDLG message is displayed, there is a
problem with your Active Handling System and your
vehicle needs service. The instrument cluster light will
also be on and a chime will sound. When this message is
displayed, the system is not working. Adjust your
driving accordingly.
ACTIVE HANDLING: Your vehicle is equipped with
an optional computer controlled system to assist the
driver in controlling the vehicle in difficult driving
conditions. You may feel or hear the system working
and see the ACTIVE HANDLING message displayed in
the DIC. This is normal when the system is operating.

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LOWER: This setting directs most of the air
through the lower ducts to the floor area of the vehicle
with some of the air also directed toward the windshield
and side window vents.
DEFOG: This setting divides the air between the
windshield and lower outlets with a small amount
directed toward the side window vents. This is useful
when fog appears on the windshield or side glass due to
rain or snowy conditions.
DEFROST: Use this setting to quickly remove fog
or frost from the windshield. This setting directs most of
the airflow to the windshield with a small amount
directed toward the lower and side window outlets.
Mode Buttons
These buttons control the air intake, the air conditioning
and the rear window defogger operation.
FRESH AIR: Press this button and it will bring
outside air into the vehicle. The light on the button will
come on when operating. Use this setting while trying to
defrost or defog windows to help clear moisture.
RECIRCULATE: Press this button to limit the
amount of fresh air entering the vehicle by recirculating
most of the air inside the vehicle. The light on the button
will come on when operating. This setting is helpful
when you are trying to cool the air quickly or to limit
odors entering the vehicle. RECIRCULATE cannot be
used while in the DEFROST or DEFOG modes.
A/C: This button turns the air conditioning
compressor off or on under most conditions. The light
on the A/C button comes on when the compressor is
operating. The air conditioning does not operate at
temperatures below approximately 35
F to 40
F
(2
C to 4
C). The air conditioning cools and
dehumidifies the air coming into the vehicle. The air
conditioning cannot be turned off in DEFROST, as it
helps to remove moisture from the vehicle. It also helps
to keep the windows clear.
The air conditioning may be forced off at high engine
speeds or high engine oil or coolant temperatures.
See ªRear Window Defoggerº later in this section for
more information.

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When adjusting the temperature, start with a driver-set
temperature of 73
F (23
C) until you determine your
comfort zone. If you choose 60
F (16
C), the
system will remain at maximum cooling and will not
automatically adjust fan speed or air delivery. If you
choose 90
F (32
C), the system will remain at
maximum heating and will not automatically adjust fan
speed or air delivery. Choosing either maximum setting
will not cause the system to heat or cool any faster.
Turning the knob past either maximum setting has no
effect on the operation of the system.
Passenger Temperature Offset
The PASSENGER knob changes the temperature on the
passenger's side of the vehicle. When the knob is in the
12 o'clock position, the passenger's temperature is the
same as the driver's. Turn the knob clockwise for
warmer air on the passenger's side, counterclockwise for
cooler air. If the driver
-set temperature is set at 60
F
(16
C) or 90
F (32
C), turning the passenger knob
has no effect because the system is locked at a
maximum setting.Automatic Operation
Press the AUTO button to place the entire system in the
automatic mode. After a five
-second display of the
current settings, only the word AUTO and the outside
temperature will be shown on the digital display. The
system will operate to achieve your comfort set
temperature as quickly as possible. If you have set the
driver temperature at 60
F (16
C) or 90
F (32
C),
the system will not operate automatically until a
different temperature is selected. The AUTO control
system works best with the windows up and the
removable roof installed or the convertible top up.
A Typical Cold Weather Example:
Your vehicle has been parked outside overnight in cold
weather (below 32
F/ 0
C) and you have set the driver
temperature at 73
F (23
C) and have selected the
AUTO mode. The system will automatically adjust the
temperature output to maximum heating. The fan will
start at a low speed. This is to avoid blowing cold air
into the vehicle. The length of the delay depends on the
amount of time since the engine was last started, the
outside temperature and the engine coolant temperature.
As the coolant warms up, the fan speed will gradually
increase. Air will flow to the floor with some air to
the windshield to prevent fogging under most
normal conditions.

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The air conditioning removes moisture from the air, so
you may notice water dripping from under the vehicle
when it is idling or after it has been turned off.
This is normal.
Heating
The heater works best if you keep the windows closed.
Maximum heating will occur when airflow direction is
in the lower mode and the temperature control knob
(on a manual climate control system) is all the way in
the red area. These settings will be selected by the
Automatic Electronic Dual Climate Control System if
operating in AUTO when maximum heating is required.
The BI
-LEVEL setting is designed for use on sunny
days when the air is only moderately warm or cool.
On days like these, the sun may adequately warm your
upper body, but your lower body may not be warm
enough. The BI
-LEVEL setting will direct cooler
airflow to your upper body and warmer air to the
floor area.
If you have the optional engine coolant heater and use it
during cold weather 0
F (
-18
C) or lower, the heating
system will provide heat more quickly because the
coolant is already warmed. See ªEngine Coolant Heaterº
in the Index.
Defogging and Defrosting
To rapidly defrost the windshield, the FRONT defrost
mode (Automatic Electronic Dual Climate Control
System) or defrost mode (manual control system)
should be used and the fan speed should be adjusted to
the highest speed. With the manual control system, turn
the temperature control knob all the way to the red area.
To keep the windshield clear and provide heated air to
the floor area of the vehicle, use the DEFOG setting.
Your vehicle is equipped with side window defogger
vents located near the side rearview mirrors.
Rear Window Defogger
REAR: This button turns the rear defogger and the
optional heated outside mirrors on. The light on the
button will come on when operating. The system
automatically shuts off after approximately 10 minutes.
If further defogging is desired, press the button again
and it will operate for about five more minutes.
The rear window defogger operates only when the
engine is running.

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Towing Your Vehicle
CAUTION:
To help avoid serious personal injury to you
or others:

Never let passengers ride in a vehicle that is
being towed.

Never tow faster than safe or posted speeds.

Never tow with damaged parts not
fully secured.

Never get under your vehicle after it has
been lifted by the tow truck.

Always secure the vehicle on each side with
separate safety chains when towing it.

Use only the correct hooks.
NOTICE:
Use the proper towing equipment to avoid
damage to the bumper, fascia or fog lamp areas
of the vehicle.
With current trends in automotive styles and design, it is
essential that the correct towing equipment is used to
tow a vehicle. Your vehicle can be towed with wheel
-lift
or car
-carrier equipment.
Consult your dealer or a professional towing service if
you need to have your vehicle towed. See ªRoadside
Assistanceº in the Index.
Engine Overheating
You will find an engine coolant temperature gage on the
instrument cluster and a COOLANT OVER TEMP
message on the Driver Information Center (DIC).
Overheated Engine Protection
Operating Mode
Should an overheated engine condition exist and the
messages COOLANT OVER TEMP and REDUCED
ENGINE POWER are displayed, along with the Check
Engine light, an overheat protection mode which
alternates firing groups of cylinders helps prevent
engine damage. In this mode, you will notice a loss in
power and engine performance. This operating mode
allows your vehicle to be driven to a safe place in an
emergency; you may drive up to 50 miles (80 km).

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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, change the oil and reset the
oil life monitor. See ªEngine Oilº in the Index.
If Steam Is Coming From Your Engine
CAUTION:
Steam from an overheated engine can burn you
badly, even if you just open the hood. Stay away
from the engine if you see or hear steam coming
from it. Just turn it off and get everyone away
from the vehicle until it cools down. Wait until
there is no sign of steam or coolant before you
open the hood.
If you keep driving when your engine is
overheated, the liquids in it can catch fire. You or
others could be badly burned. Stop your engine if
it overheats, and get out of the vehicle until the
engine is cool.

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NOTICE:
If your engine catches fire because you keep
driving with no coolant, your vehicle can be
badly damaged. The costly repairs would not be
covered by your warranty. See ªOverheated
Engine Protection Operating Modeº in the Index.
If No Steam Is Coming From Your Engine
If you get an engine overheat warning but see or hear no
steam, the problem may not be too serious. Sometimes
the engine can get a little too hot when you:

Climb a long hill on a hot day.

Stop after high
-speed driving.

Idle for long periods in traffic.If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. If your air conditioner is on, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
3. If you're in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving
-- AUTOMATIC OVERDRIVE (
) or
THIRD (3) for automatic transmissions.
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn't come back on, you can
drive normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there's still no sign of steam, idle the engine for three
minutes while you're parked. If you still have the
warning, turn off the engine and get everyone out of the
vehicle until it cools down. Also, see ªOverheated
Engine Protection Operating Modeº listed previously in
this section.
You may decide not to lift the hood but to get service
help right away.

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Cooling System
When you decide it's safe to lift the hood, here's what
you'll see:
A. Electric Engine Cooling Fans
B. Coolant Surge Tank
CAUTION:
An electric engine cooling fan under the hood can
start up even when the engine is not running and
can injure you. Keep hands, clothing and tools
away from any underhood electric fan.
If the coolant inside the coolant surge tank is boiling,
don't do anything else until it cools down.

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The coolant level should be at or above the
FULL COLD mark. If it isn't, you may have a
leak in the radiator hoses, heater hoses, radiator, water
pump or somewhere else in the cooling system.
CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Don't touch them. If you
do, you can be burned.
Don't run the engine if there is a leak. If you run
the engine, it could lose all coolant. That could
cause an engine fire, and you could be burned.
Get any leak fixed before you drive the vehicle.
NOTICE:
Engine damage from running your engine
without coolant isn't covered by your warranty.
See ªOverheated Engine Protection Operating
Modeº in the Index.

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NOTICE:
When adding coolant, it is important that you use
only DEX
-COOL
(silicate-free) coolant.
If coolant other than DEX-COOL is added to the
system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the use
of coolant other than DEX
-COOL
is not
covered by your new vehicle warranty.
If there seems to be no leak, with the engine on, check to
see if the electric engine cooling fans are running. If the
engine is overheating, both fans should be running. If
they aren't, your vehicle needs service.
How to Add Coolant to the Coolant
Surge Tank
If you haven't found a problem yet, but the coolant level
isn't at the FULL COLD mark on the coolant surge
tank, add a 50/50 mixture of clean, drinkable water and
DEX
-COOL
coolant at the coolant surge tank, but be
sure the cooling system, including the coolant surge tank
pressure cap, is cool before you do it. (See ªEngine
Coolantº in the Index for more information.)