2015 Lexus GS450h ABS

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4-5. Using the driving support systems
■When the message is displayed on the multi-information display showing that
TRAC has been disabled even if the VSC OFF switch has not been pressed
TRAC cannot be operated. Contact your Lexus dealer.
■VGRS is disabled when
VGRS may stop operating in the following situations.
In this event, the steering wheel may move from its straight forward position, but it
will return when the system restarts.
●The steering wheel is operated for an extended period of time while the vehicle is
stopped or is moving very slowly.
●When force is continuously applied for a long time with the steering wheel turned
as far as it will go.
The center position of the steering wheel may change when VGRS is disabled. How-
ever, the position will return to normal after VGRS is reactivated.
■When the battery is disconnected
The steering wheel may move from its straight forward position, but this will be cor-
rected automatically when driving.
■Sounds and vibrations caused by the ABS, brake assist, VSC, TRAC and VGRS sys-
tems
●A sound may be heard from the engine compartment when the brake pedal is
depressed repeatedly, when the hybrid syst em is started or just after the vehicle
begins to move. This sound does not indicate that a malfunction has occurred in
any of these systems.
●Any of the following conditions may occur when the above systems are operating.
None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard after the vehicle comes to a stop.
• The brake pedal may pulsate slightly after the ABS is activated.
• The brake pedal may move down slightly after the ABS is activated.
■EPS, VGRS and DRS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be heard.
This does not indicate a malfunction.
■Reactivation of the TRAC/VSC systems
Even after the TRAC/VSC systems have been turned off, turning the hybrid system
off and then on again will automatically reactivate the TRAC/VSC systems.
■Reactivation of the TRAC sy stem linked to vehicle speed
When only the TRAC system is turned off, the TRAC system will turn on when vehi-
cle speed increases. However, when both TRAC/VSC systems are turned off, the
systems will not turn on even when vehicle speed increases.

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2894-5. Using the driving support systems
4
Driving
■Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from overheat-
ing when there is frequent steering input over an extended period of time. The steer-
ing wheel may feel heavy as a result.
* Should this occur, refrain from excessive
steering input or stop the vehicle and tu rn the hybrid system off. The EPS system
should return to normal within 10 minutes.
*: If the LKA (Lane-Keeping Assist) system cannot operate in this case, a warning
message will be shown on the multi-information display.
CAUTION
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded. (such as excessively
worn tires on a snow covered road).
●The vehicle hydroplanes while driving at high speed on wet or slick roads.
■Stopping distance when the ABS is operating may exceed that of normal condi-
tions
The ABS is not designed to shorten the ve hicle’s stopping distance. Always main-
tain a safe distance from the vehicle in front of you, especially in the following situa-
tions:
●When driving on dirt, gravel or snow-covered roads
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes or uneven surfaces
■TRAC may not operate effectively when
Directional control and power may not be achievable while driving on slippery
road surfaces, even if the TRAC system is operating.
Drive the vehicle carefully in conditions where stability and power may be lost.
■When the VSC is activated
The slip indicator light flashes. Always drive carefully. Reckless driving may cause
an accident. Exercise particular care when the indicator light flashes.
■When the TRAC/VSC systems are turned off
Be especially careful and drive at a spee d appropriate to the road conditions. As
these are the systems to help ensure vehicle stability and driving force, do not turn
the TRAC/VSC systems off unless necessary.

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4-5. Using the driving support systems
CAUTION
■Replacing tires
Make sure that all tires are of the specified size, brand, tread pattern and total load
capacity. In addition, make sure that the tires are inflated to the recommended tire
inflation pressure level.
The ABS, TRAC and VSC systems will not function correctly if different tires are
installed on the vehicle.
Contact your Lexus dealer for further information when replacing tires or wheels.
■Handling of tires and the suspension
Using tires with any kind of problem or modifying the suspension will affect the
driving assist systems, and may cause a system to malfunction.

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4-5. Using the driving support systems
◆Suspension control
When the system determines that there is a high possibility of a frontal
collision, the operation of AVS ( P. 285) optimally controls the damp-
ing force of the shock absorber.
◆Steering control (if equipped)
Vehicles with VGRS
There is a high possibility of collisi on and if the steering wheel is oper-
ated, the steering gear ratio is chan ged by VGRS to help improve the
response to steering input.
Vehicles with LDH
There is a high possibility of collisi on and if the steering wheel is oper-
ated, the steering angles of the fr ont and rear wheels and the heaviness
of the steering wheel are controlled by LDH, thus heightening respon-
siveness in response to the steering operation.
◆Driver monitor system (if equipped)
When the system determines that there is a possibility of a collision, and
either the driver is not facing forwar d or the driver’s eyes are closed,
PCS warnings are given in advance to warn the driver. If the system
determines that the conditions to operate pre-collision alert braking
have been met even when the possib ility of a collision increases further,
pre-collision alert braking will operate.

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4-5. Using the driving support systems
CAUTION
■Cautions regarding the assist contents of the system
By means of alarms and brake control, the pre-collision system is intended to assist
the driver in avoiding collisions through the process of LOOK-JUDGE-ACT.
There are limits to the degree of assistance the system can provide, so please keep
in mind the following important points.
●Assisting the driver in watching the road
The pre-collision system is only able to detect obstacles directly in front of the
vehicle, and only within a lim ited range. It is not a mechanism that allows careless
or inattentive driving, and it is not a system that can assist the driver in low-visibil-
ity conditions. It is still necessary for the driver to pay close attention to the vehi-
cle’s surroundings.
●Assisting the driver in making correct judgment
When attempting to estimate the possibility of a collision, the only data available
to the pre-collision system is that from ob stacles it has detected directly in front of
the vehicle. Therefore, it is absolutely necessary for the driver to remain vigilant
and to determine whether or not there is a possibility of collision in any given situ-
ation.
●Assisting the driver in taking action
The pre-collision system’s braking assist feature is designed to help reduce the
severity of a collision, and so only acts wh en the system has judged that a collision
is unavoidable. This system by itself is not capable of automatically avoiding a col-
lision or bringing the vehicle to a stop sa fely. For this reason, when encountering a
dangerous situation the driver must take direct and immediate action in order to
ensure the safety of all involved.
NOTICE
■Precautions for cleaning the driver monitor sensor
●Gently wipe the sensor with a soft cloth to prevent damage.
●Wipe any excess dirt with a cloth dampen ed with neutral detergent, all liquids
having been wringed out of the cloth. After that, wipe again with a dry cloth.
●Do not use benzene, thinner, glass cleaners, wax, etc.

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4376-3. Do-it-yourself maintenance
6
Maintenance and care
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN”
lines on the tank.
■Adding fluid
Make sure to check the fluid type and prepare the necessary item.
■Brake fluid can absorb moisture from the air
Excess moisture in the brake fluid can cause a dangerous loss of braking efficiency.
Use only newly opened brake fluid.
Brake fluid
Fluid typeFMVSS No.116 DOT 3 or SAE J1703 brake fluid
ItemsClean funnel
CAUTION
■When filling the reservoir
Take care as brake fluid can harm your hands and eyes and damage painted sur-
faces. If fluid gets on your hands or in your eyes, flush the affected area with clean
water immediately. If you still experience discomfort, see a doctor.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level to go down slightly as the brake pads wear out
or when the fluid level in the accumulator is high.
If the reservoir needs frequent refil ling, there may be a serious problem.

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6-3. Do-it-yourself maintenance
Air conditioning filter
Turn the power switch off.
Open the glove box. Lift up the
side with the stay, disconnect the
stay tabs and remove the parti-
tion by pulling horizontally.
Press the tabs and remove the fil-
ter cover.
Press the tabs and remove the fil-
ter case.
The air conditioning filter must be changed regularly to maintain air
conditioning efficiency.
Removal method
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6-3. Do-it-yourself maintenance
Checking and replacing fuses
Turn the power switch off.
After a system failure, see “Fuse layout and amperage ratings” for
details about which fuse to check. ( P. 466)
Open the fuse box cover.
Engine compartment
Remove the engine compart-
ment cover ( P. 430) and
remove all of the clips.
Push the tabs on either side to
detach the lock and lift the lid off
while pulling the lock plate.
When installing the lid, check that
the lock plate and the tabs on either
side are connected correctly.
If any of the electrical components do not operate, a fuse may have
blown. If this happens, check and replace the fuses as necessary.
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