light lexus LS400 1998 Audio System / LEXUS 1998 LS400 (OM50498U) Repair Manual

STARTING AND DRIVING
162
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1
Power mode 2
Normal mode 3
Snow mode
2. Set the driving pattern selector switch to the ”Normal”
position.
Your transmission has a driving pattern selector switch which allows
you to select ”Power”, ”Normal” or ”Snow” mode to suit your
driving condition. For ordinary driving, Lexus recommends that
you use the ”Normal” position to improve fuel economy.
3. For more powerful acceleration and sporty driving, use the
”Power” position.
In the POWER position, the ”ECT PWR” 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
position.
For ”Snow” mode, see ”Electronic Throttle Control System” on
page 167.
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”D” (Drive) position 2
Brake pedal
4. With your foot holding down the brake pedal, shift the
selector lever to ”D”.
Always use the ”D” position to improve fuel economy and quiet
driving. Only in this position, shifting into the overdrive gear is
possible. However, while the engine coolant temperature is low, the
transmission will not shift into the overdrive gear even in the ”D”
position. (See ”(b) Using engine braking” and ”(f) Good driving
practice” for exceptions.)
CAUTION
Never put your foot on the accelerator pedal while shifting.

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167
(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
”If you cannot shift automatic transmission selector lever” on page
209.
(i) If the ”ECT PWR” indicator light flashes
If the ”ECT PWR” indicator light flashes, contact your Lexus dealer
as soon as possible. There may be trouble in the transmission
system.
ELECTRONIC THROTTLE
CONTROL SYSTEM
The electronic throttle control system always maintains
appropriate engine output in relation to the accelerator opening
in all driving conditions.
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Power mode 2
Normal mode 3
Snow mode
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
168In the power mode, the ”ECT PWR” light in the instrument cluster
is on and the transmission is shifted up at higher vehicle speeds and
shifted down more responsively than is the normal mode.
To return to the normal mode, push the driving pattern selector
switch lightly on the ”SNOW” 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 ”SNOW”
side, the snow mode is turned on and the ”ECT SNOW” light in the
instrument cluster comes on.
To return to the normal mode, push the driving pattern selector
switch on the ”SNOW” 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 snowcovered) 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.

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169
Turning on the system
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To operate the cruise control, push the main switch. This turns the
system on. The indicator light in the instrument cluster shows that
you can now set your desired cruising speed. Another push on the
switch will turn the system completely off.
When the ignition key is turned off, the main switch is also
automatically turned off. To use the cruise control again, push the
main switch again to turn it on.
CAUTION
To avoid accidental cruise control engagement, keep the main
switch off when not using the cruise control.
Setting at a desired speed
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The transmission must be in ”D” or ”4” before you set the cruise
control speed.
Bring the vehicle to the desired speed, press the control lever
downward in the ”SET/COAST” direction and release it. This sets
the vehicle at that speed. Now you may take your foot off the
accelerator pedal. If you need acceleration for example, when
passing depress the accelerator pedal enough for the vehicle to
exceed the set speed. When you release the accelerator pedal, the
vehicle will return to the speed set prior to the acceleration.
Cancelling the preset speed
You can cancel the preset speed by either of the following:
a. Pulling the control lever in the ”CANCEL” direction.
b. Depressing the brake pedal.

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171
Cruise control failure warning
If the ”CRUISE” indicator light in the instrument cluster flashes
when using the cruise control, push the main switch to turn the
system off and then push it again to turn it on.
If any of the following conditions then occurs, there is some trouble
in the cruise control system.
The indicator light does not come on.
The indicator light flashes again.
The indicator light goes out after it comes on.
If this is the case, contact your Lexus dealer and have your Lexus
inspected.
ELECTRONICALLY MODULATED
AIR SUSPENSION
(U.S.A. ONLY)
This electronically modulated air suspension adjusts the
damping effect on the shock absorbers and the vehicle height.
This adjustment is automatically made in response to the driving
conditions to provide good riding comfort and stability in all
driving conditions.
(a) Vehicle height adjustment
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This system maintains a stable vehicle height, regardless of
occupants and luggage weight. You can select one of the
following modes using a selector switch.

STARTING AND DRIVING
172”NORMAL” mode For driving on roads with a normal surface.
”HIGH” mode For driving on rough roads which are unsurfaced
or continually bumpy.
The damping effect is set slightly firmer in ”HIGH” mode. So you
may feel the vibration of the vehicle compared to in ”NORMAL”
mode. However, this does not mean a malfunction in the system. We
recommend you use a ”NORMAL” mode in normal driving.
To change the mode, push the selector switch.
”NORMAL” mode
The vehicle height remains at normal height at all driving speeds.
”HIGH” mode
The vehicle height switches between the following two vehicle
heights according to the driving conditions:
Vehicle height
Driving condition
NormalMedium and high speed driving
HighLow speed driving
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The indicator light shows ”HIGH” mode is selected.
When you turn the ignition key to the ”ON” position, the indicator
light will come on for 2 seconds in any mode.
NOTICE
For vehicles equipped with the height control switch, be sure to
turn the ignition switch off before jacking. If this is not done, the
vehicle height adjustment function will operate, which may
cause body damage.
(b) Malfunction warning
If the ”HI” indicator light blinks, there is a malfunction in this
system. Have the system checked by your Lexus dealer at the first
opportunity.

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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.
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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 light blinks.
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.
To turn off the traction control system, see page 174.
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.

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VEHICLE SKID CONTROL SYSTEM
The vehicle skid control system helps to provide comprehensive
control of the systems such as an antilock brake system,
traction control, engine control, electronically modulated air
suspension, etc. This system automatically controls the output
of the brakes or engine to help prevent the vehicle from skidding
when cornering on a slippery road surface or abrupt steering
wheel operation occurs.
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Slip indicator light
If the vehicle is going to skid during driving, the slip indicator light
flashes and an alarm sounds.
The vehicle skid control activates when the vehicle speed is about
more than 15 km/h (9 mph).Depressing the brake pedal repeatedly causes a small noise from the
engine compartment. This is a pump pulsating sound of the brake
system and it is not a malfunction.
You may hear a slight clicking noise in the engine compartment for
a few seconds when the engine is started or just after the vehicle is
started. This means that the vehicle skid control is in the selfcheck
mode and does not indicate a malfunction.
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You can turn off the vehicle skid control system by pushing the
”VSC OFF” switch. The ”VSC OFF” indicator comes on. At
this time, the traction control system also turns off. You cannot
turn off either one of them. Pushing the ”VSC OFF” switch a
second time turns the system back on and extinguishes the ”VSC
OFF” indicator light.
When you turn the ignition switch on, this system always turns on.

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Vehicle skid control failure warning
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In the following cases, the warning message appears and the
reminder light next to the warning message and the ”VSC OFF”
indicator light come on. And the warning tone also sounds.
(a) After the removal of the battery terminals (See ”Initial
adjustment of vehicle skid control system” described below.)
(b) If the vehicle skid control system malfunctions
If the message appears for the cause of (b), have your vehicle
checked by Lexus dealer as soon as possible.
Although the message appears, there is no problem to continue your
normal driving.
Initial adjustment of vehicle skid control system
After the battery terminals are disconnected, an initial adjustment
should be made. At this time, the reminder light comes on and the
warning message appears in the multi information display.
Make an initial adjustment in the following ways:
1. Apply the parking brake and put the transmission in ”P”.
2. Connect the battery terminals.
3. Turn the ignition switch on. At this time, the ”VSC OFF”
indicator light comes on and then about 6 seconds later, the reminder
light comes on and the ”CHECK VSC” warning message appears in
the multi information display.
4. The warning message and the ”VSC OFF” indicator light go out
about 15 seconds after the ignition switch is turned on. If the vehicle
is shaken after the ignition switch is turned to ”ON”, it may take
longer to go out the warning message.
If the warning message does not go out about 1 minute after you turn
the ignition switch on, turn it off and then on again.
If the vehicle is on the moving object like a ship or turntable, an
accurate adjustment cannot be made. Move the vehicle on the
ground (or the part not causing vibrations to the vehicle) and make
an adjustment from step 1.

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CAUTION
Do not rely excessively on the vehicle skid control system.
Even if the vehicle skid control system is operating, it is not
that your vehicle is absolutely safe. Reckless driving will
result in an unexpected accident. Always keep safety
driving in mind. If the slip indicator light flashes, sounding
an alarm, special care should be taken while driving.
Only use tires of specified size. The size, manufacturer,
brand and tread pattern for all 4 tires should be the same.
If you use the tires other than specified, or different type or
size, the vehicle skid control system may not function
correctly. When replacing the tires or wheels, contact your
Lexus dealer.
BRAKE SYSTEM
The tandem master cylinder brake system is a hydraulic system with
two separate subsystems. If either subsystem 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.
Brake booster
The brake booster uses engine vacuum to powerassist 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.