engine LEXUS SC300 1999 Workshop Manual

STARTING AND DRIVING
239
(f) Good driving practice
If the transmission repeatedly upshifts and downshifts
between the fourth and overdrive gears when climbing a
gentle slope, shift the selector lever to the º3º position. Be
sure to shift the selector lever to the ºDº position after
climbing the slope.
 When towing a trailer, in order to maintain ef ficient engine
braking and electrical charging performance, do not use
overdrive. The selector lever must be in the º3º position.
CAUTION
Always keep your foot on the brake pedal while stopped with
the engine running. This prevents the vehicle from creeping.
NOTICE
Do not hold the vehicle on an upgrade with the
accelerator pedal. This can cause the transmission to
overheat. Always use the brake pedal or parking brake.
(g) Rocking your vehicle if stuck
CAUTION
If your vehicle becomes stuck in snow, mud, sand, etc., then
you may attempt to rock the vehicle free by moving it forward
and backward. Do not attempt this procedure if people or
objects are anywhere near the vehicle. During the rocking
operation the vehicle may suddenly move forward or back as
it becomes un±stuck, causing injury or damage to nearby
people or objects.

STARTING AND DRIVING
240
NOTICE
If you rock your vehicle, observe the following
precautions to prevent damage to the transmission and
other parts.
Do not depress the accelerator pedal while shifting the
selector lever or before the transmission is completely
shifted to forward or reverse gear.
 Do not race the engine and avoid spinning the wheels.
 If your vehicle remains stuck after rocking the vehicle
several times, consider other ways such as towing.
(h) If you cannot shift the selector lever
If you cannot shift the selector lever even though the brake
pedal is depressed, use the shift lock override button. For
instructions, see ºIf you cannot shift automatic transmission
selector leverº on page 306.

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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
245
If the vehicle speed falls below about 40 km/h (25 mph), the
preset speed will be automatically cancelled.
If the vehicle speed drops 16 km/h (10 mph) below the preset
speed, the preset speed will also automatically be cancelled.
If the preset speed automatically cancels out for other than
these reasons, have your vehicle checked by your Lexus
dealer at the earliest opportunity.
Resetting to a faster speed
Press the control lever upward in the ºRES/ACCº direction
and hold it. Release the lever when the desired speed is
attained. While the lever is held upward, the vehicle will
gradually gain speed.
When
the difference between the actual vehicle speed and the
set speed is less than 5 km/h (3 mph), the set speed can be
increased 1.6 km/h (1 mph) each time by pressing the control
lever upward in the ºRES/ACCº direction quickly within 0.6
seconds.
However, a quicker way to reset is to accelerate the vehicle
and then press the control lever downward in the
ºSET/COASTº direction.
Resetting to a slower speed
Press the control lever downward in the ºSET/COASTº
direction and hold it. Release the lever when the desired
speed is attained. While the lever is held downward, the
vehicle speed will gradually decrease. When
the difference between the actual vehicle speed and the
set speed is less than 5 km/h (3 mph), the set speed can be
lowered 1.6 km/h (1 mph) each time by pressing the control
lever downward in the ºSET/COASTº direction quickly
within 0.6 seconds.
However, a quicker way to reset is to depress the brake pedal
and then press the control lever downward in the
ºSET/COASTº direction.
Even if you downshift the transmission from ºDº to º4º
(SC400) or from ºDº to º3º (SC300) with the cruise control
on, engine braking will not be applied because the cruise
control is not cancelled. To decrease the vehicle speed, reset
to a slower speed with the cruise control lever or depress the
brake pedal. If you use the brake pedal, cruise control is
cancelled.
Resuming the preset speed
If the preset speed is cancelled by pulling the control lever or
by depressing the brake pedal, pushing the lever up in the
ºRES/ACCº direction will restore the speed set prior to
cancellation. However, once the vehicle speed falls below
about 40 km/h (25 mph), the preset speed will not be resumed.
Cruise control failure warning
If the ºCRUISEº indicator light in the instrument cluster
flashes five times and then goes out when using the cruise
control, it means that there is trouble in the cruise control
system. Contact your Lexus dealer.

STARTING AND DRIVING
247
You can turn off the traction control system by pushing
the ºTRAC OFFº switch. The ºTRAC OFFº indicator/
warning light will then come on. Pushing the ºTRAC
OFFº switch a second time turns the system back on and
extinguishes the ºTRAC OFFº indicator/warning light.
You may hear a slight clicking noise in the engine
compartment when the engine is started. This means that the
traction control system is in the self±check mode, and does
not indicate malfunction.
When the traction control system is operating, you may feel
vibration of your vehicle, caused by operation of the brakes.
This indicates the system is functioning properly.
When getting the vehicle out of mud or new snow, etc. the
traction control system will help operate to prevent the wheels
from spinning.

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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.

STARTING AND DRIVING
250
Anti±lock brake system
The anti±lock brake system is designed to automatically
help prevent lock±up of the wheels during a sudden brake
or braking on slippery road surfaces. This assists in
providing directional stability and steering performance
of the vehicle under these circumstances.
The anti±lock brake system becomes operative after the
vehicle has accelerated to a speed in excess of approximately
10 km/h (6 mph). It stops operating when the vehicle
decelerates to a speed below approximately 5 km/h (3 mph).
You may hear a sound in the engine compartment for a few
seconds when the engine is started or just after the vehicle is
started. This means that the anti±lock brake system is in the
self±check mode, and does not indicate a malfunction.
Effective way to press the ABS brake pedal: When the anti±
lock brake system function is in action, you may feel the brake
pedal pulsating and hear a noise. In this situation, to let the anti±
lock brake system work for you, just hold the brake pedal down
more firmly. Do not pump the brake in a panic stop. Pumping the
brake pedal makes the stopping distance longer.

DRIVING TIPS
259
BREAK±IN PERIOD
Drive gently and avoid high speeds.
You need not follow a break±in schedule with your new
Lexus. But following a few simple tips for the first 1600 km
(1000 miles) can add to the future economy and long life of
your vehicle:

Do not drive over 88 km/h (55 mph).

Avoid overrevving. Maintain engine speed between 2000
and 4000 rpm.

Avoid full±throttle starts.

Try to avoid hard stops during the first 300 km (200 miles).

Do not drive for a long time at any single speed, either fast
or slow.

Do not tow a trailer during the first 800 km (500 miles).
OPERATION IN FOREIGN
COUNTRIES
If you plan to drive your Lexus in another country ...
First, comply with the vehicle registration laws.
Second, confirm the availability of the correct fuel (unleaded
and minimum octane rating).
TIPS FOR DRIVING IN VARIOUS CONDITIONS

Always slow down in gusty crosswinds. This will allow
you much better control.

Drive slowly onto curbs and, if possible, at a right angle.
Avoid driving onto high, sharp±edged objects and other
road hazards. Failure to do so can lead to severe tire
damage resulting in tire bursts.

When parking on a hill, turn the front wheels until they
touch the curb so that the vehicle will not roll. Apply the
parking brake, and place the transmission in ºPº. If
necessary, block the wheels.

Washing your vehicle or driving through deep water may
get the brakes wet. To see whether they are wet, check that
there is no traffic near you and then press the pedal lightly.
If you do not feel a normal braking force, the brakes are
probably wet. To dry them, drive the vehicle cautiously
while lightly pressing the brake pedal with the parking
brake applied. If they still do not work safely, pull to the
side of the road and call a Lexus dealer for assistance.
CAUTION

Before driving, make sure the parking brake is fully
released and that the parking brake reminder light is off.

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