Page 290 of 620
2884-5. Using the driving support systems
LS600hL_U(OM50E41U)
CAUTION
■Be sure to stop the hybrid system in the following situations in order to stop oper-
ation of the electronically modulated air suspension:
●The vehicle is parked on a curb.
●Any of the wheels is stuck in a ditch.
●It is necessary to jack up the vehicle.
●It is necessary to tow the vehicle with part of it lifted.
If the power switch remains in ON mode, the vehicle height may change, and you
may catch part of your body in the vehicle, resulting in accidental damage.
Page 291 of 620

2894-5. Using the driving support systems
4
Driving
LS600hL_U(OM50E41U)
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly, or if
the brakes are applied while dri ving on a slippery road surface
◆Brake assist
Generates an increased level of br aking force after the brake pedal is
depressed when the system detects a panic stop situation
◆VSC (Vehicle Stability Control)
Helps the driver to control skidding when swerving suddenly or turning
on slippery road surfaces
◆TRAC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from spin-
ning when starting the vehicle or accelerating on slippery roads
◆Hill-start assist control
Helps to prevent the vehicle from ro lling backward when starting on an
incline or slippery slope
◆VGRS (Variable Gear Ratio Steering)
Adjusts the wheel turning angle in accordance with the vehicle speed
and steering wheel movement
Driving assist systems
To help enhance driving safety an d performance, the following systems
operate automatically in response to various driving situations. Be
aware, however, that these systems are supplementary and should not
be relied upon too heavily when operating the vehicle.
Page 292 of 620
2904-5. Using the driving support systems
LS600hL_U(OM50E41U)
◆EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to
turn the steering wheel
◆VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the AB S, brake assist, TRAC, VSC, hill-
start assist control, EPS and VGRS systems
Helps to maintain vehicle stability when swerving on slippery road sur-
faces by controlling the brakes, hybr id system output, steering assist,
and steering ratio
◆PCS (Pre-Collision System) (if equipped)
P. 2 9 6
◆BSM (Blind Spot Monitor) (if equipped)
P. 308
Page 293 of 620
2914-5. Using the driving support systems
4
Driving
LS600hL_U(OM50E41U)
The slip indicator light will flash
while the TRAC/VSC/ABS/hill-
start assist control systems are
operating.
The stop lights and high mounted
stoplight turn on when the hill-start
assist control system is operating.
If the vehicle gets stuck in fresh snow or mud, the TRAC and VSC systems
may reduce power from the hybrid sy stem to the wheels. Pressing VSC
OFF switch to turn the sy stem off may make it easier for you to rock the
vehicle in order to free it.
■Turning off the TRAC system only
To turn the TRAC system off,
quickly press and release the
switch.
The “TRAC OFF” will be shown on
the multi-information display. Press
the switch again to turn the system
back on.
When the TRAC/VSC/ABS/hill-sta rt assist control systems are
operating
Disabling the TRAC/VSC systems
Page 295 of 620

2934-5. Using the driving support systems
4
Driving
LS600hL_U(OM50E41U)
■Hill-start assist control is operational when
●The system has detected that the vehicle is moving backward.
●The shift lever is in the D or S position.
●The brake pedal is not depressed.
■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.
●When the steering wheel is operated for an extended period of time while the vehi-
cle is stopped or is moving very slowly
●When the steering wheel has been held fully to the left or right
●When the 12-volt battery is low or the voltage temporarily drops
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.
■Sounds and vibrations caused by the ABS, brake assist, TRAC, VSC, hill-start assist
control and VGRS systems
●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 steering wheel may be moved slightly or a sound may be heard when the
hybrid system is started or stopped. None of these indicate that a malfunction has
occurred.
■EPS 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.
Page 296 of 620

2944-5. Using the driving support systems
LS600hL_U(OM50E41U)
■Reactivation of the TRAC system 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.
■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 ov er 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
Page 297 of 620

2954-5. Using the driving support systems
4
Driving
LS600hL_U(OM50E41U)
CAUTION
■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.
Do not drive the vehicle in conditions where stability and power may be lost.
■Hill- start assist control does not operate effectively when
Do not overly rely on the hill-start assist control. The hill-start assist control may not
operate effectively on steep inclines and roads covered with ice.
■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.
■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.
Page 305 of 620

3034-5. Using the driving support systems
4
Driving
LS600hL_U(OM50E41U)
■Situations in which the pre-collision system does not function properly
The system may not function effectively in situations such as the following:
●On roads with sharp bends or uneven surfaces
●If a vehicle suddenly moves in front of your vehicle, such as at an intersection
●If a vehicle suddenly cuts in front of your vehicle, such as when overtaking
●In inclement weather such as heavy rain, fog, snow or sand storms
●If the vehicle is skidding when VSC is not operating
●When an extreme change in vehicle height occurs
●When only part of your vehicle’s front en d collides with, or contacts, a vehicle or
object in a frontal collision
●When the radar sensor moves off position due to its surrounding area being sub-
jected to a strong impact
●If an obstacle in front of the vehicle is small
●When the system judges that the driver performed a collision avoidance operation
via the accelerator pedal, brake pedal, or steering wheel
■Automatic cancelation of the pre-collision system
When a malfunction occurs due to sensor co ntamination, etc. that results in the sen-
sors being unable to detect obstacles, the pre-collision system will be automatically
disabled. In this case, the system will not activate even if there is a collision possibility.
■When there is a malfunction in the system
The pre-collision system warning light will flash and warning messages will be dis-
played. ( P. 495, 503)