power LEXUS SC300 1999 Owner's Guide

STARTING AND DRIVING
241
ELECTRONIC THROTTLECONTROL SYSTEM
The electronic throttle control system always maintains
appropriate engine output in relation to the accelerator
opening in all driving conditions.
The electronic throttle control system has 3 modes:
Normal, Power and Snow modes.
Normal mode: For ordinary driving, Lexus recommends
that you use the normal mode to improve fuel economy.
Power mode: For more powerful acceleration and sporty
driving.

STARTING AND DRIVING
242In the power mode, the ºECT PWRº light in the instrument
cluster is on and the transmission is shifted up at higher
vehicle speeds and shifted down more responsively than in
the normal mode.
To return to the normal mode, push the driving pattern
selector switch lightly on the ºSNOWº side.
Snow mode: For slippery road surfaces such as in snow. In
this mode, the spinning of the rear wheels is controlled
appropriately.
When you push the driving pattern selector switch on the
ºSNOWº side, the snow mode is turned on and the ºECT
SNOWº light in the instrument cluster comes on.
To return to the normal mode, push the driving pattern
selector switch on the ºSNOWº side again.
When you turn the ignition switch off in the snow mode, the
mode automatically changes to the normal mode.
CRUISE CONTROL
The cruise control allows you to cruise the vehicle at a
desired
speed over 40 km/h (25 mph) with your foot off the
accelerator pedal.
Your cruising speed can be maintained although a slight speed
change may occur when driving up or down a gradient, within
the limits of engine performance. On steeper hills, a great
speed change will occur so it is better to drive without the
cruise control.
When the cruise control is on, the driving pattern of the
automatic transmission is fixed in the normal position,
regardless of the position of the selector switch.
CAUTION
 To help maintain maximum control of your vehicle, do not
use the cruise control when driving in heavy or varying
traffic, or on slippery (rainy, icy or snow±covered) or
winding roads.
 Avoid vehicle speed increases when driving downhill. If the
vehicle speed is too fast in relation to the cruise control set
speed, cancel the cruise control then downshift the
transmission to use engine braking to slow down.

STARTING AND DRIVING
246
TRACTION CONTROL SYSTEM
The traction control system automatically helps control
the spinning of the rear wheels which may occur when
accelerating on slippery road surfaces, thus assisting
driver to control the driving power of the rear wheels.
When you turn the ignition switch on, this system always
turns on. Leave the system on during ordinary driving so
that it can operate when needed. When traction control
is applied, the slip indicator blinks.

STARTING AND DRIVING
248
Traction control failure warning
If the ºTRAC OFFº indicator/warning light flashes, contact
your Lexus dealer as soon as possible. There may be trouble
in the traction control system.
CAUTION
Under certain slippery road conditions, full traction of the
vehicle and power to the rear wheels cannot be maintained,
even though the traction control system is in operation. Do not
drive the vehicle under any speed or maneuvering conditions
which will cause the vehicle to lose traction. In situations
where the road surface is covered with ice or snow, your
vehicle should be fitted with snow tires or tire chains. Always
drive at an appropriate and cautious pace.
BRAKE SYSTEM
The tandem master cylinder brake system is a hydraulic
system with two separate sub±systems. If either sub±system
should fail, the other will still work. However, the pedal will
be harder to press, and your stopping distance will be longer.
Also, the brake system warning light may come on.
CAUTION
Do not drive your vehicle with only a single brake system.
Have your brakes fixed immediately.

STARTING AND DRIVING
249
Brake booster
The brake booster uses engine vacuum to power±assist the
brakes. If the engine should quit while you are driving, you
can bring the vehicle to a stop with normal pedal pressure.
There is enough reserve vacuum for one or two stops but no
more!
CAUTION
Do not pump the brake pedal if the engine stalls. Each push
on the pedal uses up your vacuum reserve.
 Even if the power assist is completely lost, the brakes will
still work. But you will have to push the pedal hard ± much
harder than normal. And your braking distance will be
longer.

DRIVING TIPS
260

Do not rest your foot on the brake pedal while
driving. It can cause dangerous overheating,
needless wear, and poor fuel economy.

To drive down a long or steep hill, reduce your speed
and downshift. Remember, if you ride the brakes
excessively, they may overheat and not work
properly. See page 234.

Be careful when accelerating, upshifting,
downshifting or braking on a slippery surface. The
abrupt change in engine speed, such as sudden
acceleration or engine braking, could cause the
vehicle to spin or skid.

Do not drive in excess of the speed limit. Even if the
legal speed limit permits it, do not drive over 140
km/h (85 mph) unless your vehicle has high±speed
capability tires. Driving over 140 km/h (85 mph)
may result in tire failure, loss of control and possible
injury. Be sure to consult a tire dealer to determine
whether the tires on your vehicle are high±speed
capability tires or not before driving at such speeds.

Do not continue normal driving when the brakes are
wet. If they are wet, your vehicle will require a
longer stopping distance, and it may pull to one side
when the brakes are applied. Also, the parking
brake will not hold the vehicle securely.WINTER DRIVING TIPS
Make sure you have a proper freeze protection of engine
coolant.
Your coolant must contain ethylene±glycol type coolant for
a proper corrosion protection of aluminum components. Use
ºToyota Long Life Coolantº or equivalent. See ºChecking
the engine coolant levelº on page 347 for instructions.
NOTICE
Do not use alcohol type antifreeze or plain water alone.
When it is extremely cold, we recommend to use 60%
solution for your Lexus, to provide protection down to about
±50 C (±58F). Do not use more than 70% solution for better
coolant performance.
Check the condition of the battery and cables.
Cold temperatures reduce the capacity of any battery, so it
must be in top shape to provide enough power for winter
starting. Page 380 tells you how to visually inspect the
battery. Your Lexus dealer and most service stations will be
pleased to check the battery charge level.
Make sure the engine oil viscosity is suitable for the cold
weather.
See page 346 for recommended viscosity. Leaving a heavy
summer oil in your vehicle during winter months may cause
harder starting. If you are not sure about which oil to use, call

DRIVING TIPS
266
Tires

Ensure that your vehicle's tires are properly inflated.
Adjust the tire pressure to the recommended cold tire
pressure indicated below:
SC400, SC 300 ± Front 220 kPa (2.2 kgf/cm
2 or bar, 32 psi)
Rear 220 kPa (2.2 kgf/cm2 or bar, 32
psi)

The trailer tires should be inflated to the pressure
recommended by the trailer manufacturer in respect to the
total trailer weight.
Trailer lights

Trailer lights must comply with federal, state/provincial
and local regulations. See your local recreational vehicle
dealer or rental agency for the correct type of wiring and
relays for your trailer. Check for correct operation of the
turn signals and stop lights each time you hitch up. Direct
splicing may damage your vehicle's electrical system and
cause a malfunction of your lights.
Break±in schedule

Lexus recommends that you do not tow a trailer with a new
vehicle or a vehicle with any new power train component
(engine, transmission, differential, wheel bearing, etc.) for
the first 800 km (500 miles) of driving.
Maintenance

If you tow a trailer, your vehicle will require more frequent
maintenance due to the additional load. For this
information, please refer to the scheduled maintenance
information in the ºOwner's Manual Supplement/
Maintenance Scheduleº.

Retighten all fixing bolts of the towing ball and bracket
after approximately 1000 km (600 miles) of trailer driving.
Pre±towing safety check

Check that your vehicle remains level when a loaded or
unloaded trailer is hitched. Do not drive if the vehicle has
an abnormal nose±up or nose±down condition, and check
for improper tongue load, overload, worn suspension or
other possible causes.

Make sure the trailer cargo is securely loaded so that it
cannot shift.

Check that your rear view mirrors conform to any federal,
state/provincial or local regulation. If they do not, install
required rear view mirrors appropriate for towing
purposes.

DRIVING TIPS
271
Supplement/Maintenance Scheduleº.)
CAUTION
Never turn off the engine to coast down hills. Your power
steering and brake booster will not function without the
engine running. Also, the emission control system operates
properly only when the engine is running.

IN CASE OF AN EMERGENCY
274
IF YOUR ENGINE STALLSWHILE DRIVING
If your engine stalls while driving . . . .
1. Reduce your speed gradually, keeping a straight line.
Move cautiously off the road to a safe place.
2. Turn on your emergency flashers.
3. Try starting the engine again.
If the engine will not start, see ºIf your vehicle will not startº.
CAUTION
If the engine is not running, the power assist for the brakes and
steering will not work, so steering and braking will be much
harder than usual.

IN CASE OF AN EMERGENCY
2805. Start your engine in the normal way. After starting, run it
at about 2000 rpm for several minutes with the accelerator
pedal lightly depressed.
6. Carefully disconnect the cables in the exact reverse order:
the negative cable and then the positive cable.
7. Carefully dispose of the battery cover cloths which may
now contain sulfuric acid.
8. If removed, replace all the battery vent plugs.
If the cause of your battery discharging is not apparent (for
example, lights left on), you should have it checked.
IF YOUR VEHICLE
OVERHEATS
If your engine coolant temperature gauge indicates
overheating, if you experience a loss of power, or if you
hear a loud knocking or pinging noise, the engine has
probably overheated.