brake LEXUS LS600H 2017 Workshop Manual

3384-5. Using the driving support systems
LS600h/LS600hL_EE(OM50G20E)
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly, or if
the brakes are applied while driv ing on a slippery road surface
◆Brake assist
Generates an increased level of braking 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
◆TRC (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 rolling 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 and performance, the following systems
operate automatically in response to various driving situations. Be
aware, however, that these system s are supplementary and should not
be relied upon too heavily when operating the vehicle.

3394-5. Using the driving support systems
4
Driving
LS600h/LS600hL_EE(OM50G20E)
◆EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to
turn the steering wheel
◆Active stabilizer suspension system (if equipped)
Reduces sway when cornering according to steering wheel movement
and the selected driving mode, in order to maintain a stable vehicle
posture
◆VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, brake assist, TRC, 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, hybrid system output, steering assist,
and steering ratio
◆PCS (Pre-Crash Safety system) (if equipped)
 P. 346
◆Rear Pre-Crash Safety system (if equipped)
 P. 360
◆Emergency brake signal
When the brakes are applied suddenly, the stop lights automatically
flash to alert the vehicle behind
◆BSM (Blind Spot Monitor) (if equipped)
 P. 366

3414-5. Using the driving support systems
4
Driving
LS600h/LS600hL_EE(OM50G20E)
■Turning off both TRC and VSC systems
To turn the TRC and VSC sys-
tems off, press and hold the
switch for more than 3 seconds
while the vehicle is stopped.
The VSC OFF indicator light will
come on and the “TRC OFF” will
be shown on the multi-information
display.*
Press the switch again to turn the
systems back on.
*: On vehicles with pre-crash safety system, pre-crash alert braking, pre-crash
brake assist and pre-crash braking will also be disabled. The pre-crash safety
system warning light will come on and the “Pre-crash brakes are disabled
because VSC is OFF” will be shown on the multi-information display.
( P. 346)

3424-5. Using the driving support systems
LS600h/LS600hL_EE(OM50G20E)
■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, TRC, 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 system 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 TRC/VSC systems
Even after the TRC/VSC systems have been turned off, turning the hybrid system off
and then on again will automatically reactivate the TRC/VSC systems.

3434-5. Using the driving support systems
4
Driving
LS600h/LS600hL_EE(OM50G20E)
■Reactivation of the TRC system linked to vehicle speed
When only the TRC system is turned off, the TRC system will turn on when vehicle
speed increases. However, when both TRC and VSC systems are turned off, the sys-
tems 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 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 turn 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.
■Operating conditions of emergency brake signal
When the following three conditions are met, the emergency brake signal will oper-
ate:
●The emergency flashers are off.
●Actual vehicle speed is over 55 km/h (35 mph).
●The brake pedal is depressed in a manner that cause the system to judge from the
vehicle deceleration that this is a sudden braking operation.
■Automatic system cancelation of emergency brake signal
The emergency brake signal will turn o ff in any of the following situations:
●The emergency flashers are turned on.
●The brake pedal is released.
●The system judges from the vehicle deceleration that is not a sudden braking oper-
ation.

3464-5. Using the driving support systems
LS600h/LS600hL_EE(OM50G20E)
◆Pre-crash warning
When a high possibility of a fron-
tal collision is detected, the pre-
crash safety system warning light
flashes, a buzzer sounds and a
message is shown on the multi-
information display to urge the
driver to take evasive action.
Pre-crash warning can be disabled
using the pre-crash braking off
switch.
◆Pre-crash seat belts (front seat only)
If the pre-crash sensor detects that a collision is unavoidable, the pre-
crash safety system will retract the seat belt before the collision occurs.
The same will happen if the driver makes an emergency braking or
loses control of the vehicle. ( P. 46)
◆Pre-crash brake assist
When there is a high possibility of a frontal collision, the system applies
greater braking force in relation to how strongly the brake pedal is
depressed.
PCS (Pre-Crash Safety system)
: If equipped
When the sensor detects that a frontal collision is highly likely or even
unavoidable, safety systems such as the brakes and seat belts are auto-
matically engaged to help avoid a collision or to lessen impact as well as
vehicle damage.

3474-5. Using the driving support systems
4
Driving
LS600h/LS600hL_EE(OM50G20E)
◆Pre-crash braking
When there is a high possibility of a frontal collision, the system warns
the driver using a warning light, warning display and buzzer. If the sys-
tem determines that a collision is unavoidable, the brakes are automati-
cally applied to help avoid a collision or to reduce the collision speed.
When the vehicle is being stopped by pre-crash braking, the brake will
be engaged for a maximum of 2 seconds and then released automati-
cally. This pre-crash braking can be canceled by depressing the accel-
erator pedal or brake pedal.
Pre-crash braking can be disabled using the pre-crash braking off switch.
◆Suspension control
When there is a high possibility of a frontal collision, the operation of
suspension control helps prevent the front of the vehicle from dropping
when the brakes are applied suddenly.
◆Steering gear control (VGRS) (vehicles with camera sensors)
When the system determines that a collision is unavoidable, the steer-
ing gear ratio is changed to help improve the response to steering
input.
◆Driver monitor system (if equipped)
When the system determines that there is a possibility of a collision, and
either the driver is not facing forward or the driver’s eyes are closed,
pre-crash warnings are given in adva nce to warn the driver. If the sys-
tem determines that the conditions to operate pre-crash alert braking
have been met even when the possibility of a collision increases further,
pre-crash alert braking will operate.
Pre-crash alert braking can be disabled using the pre-crash braking off switch.

3504-5. Using the driving support systems
LS600h/LS600hL_EE(OM50G20E)
■The pre-crash safety system is operational when
●Pre-crash warning:
Vehicles without camera sensors
• The pre-crash braking off switch is not pressed.
• Vehicle speed is greater than about 15 km/h (10 mph).
• The speed at which your vehicle is approaching the obstacle or the vehicle run-
ning ahead of you is greater than about 15 km/h (10 mph).
Vehicles with camera sensors
• The pre-crash braking off switch is not pressed.
• Vehicle speed is greater than about 5 km/h (4 mph).
• The speed at which your vehicle is approaching the obstacle or the vehicle run-
ning ahead of you is greater than about 5 km/h (4 mph).
●Pre-crash seat belts (operating conditions A):
• Vehicle speed is greater than about 30 km/h (19 mph).
• The system detects sudden braking or skidding.
• The front occupants are wearing a seat belt.
●Pre-crash seat belts (operating conditions B):
• Vehicle speed is greater than about 5 km/h (4 mph).
• The speed at which your vehicle is approaching the obstacle or the vehicle run-
ning ahead of you is greater than about 30 km/h (19 mph).
• The front occupants are wearing a seat belt.
●Pre-crash brake assist:
• The VSC OFF switch is not pressed.
• Vehicle speed is greater than about 30 km/h (19 mph).
• The speed at which your vehicle is approaching the obstacle or the vehicle run-
ning ahead of you is greater than about 30 km/h (19 mph).
• The brake pedal is depressed.

3524-5. Using the driving support systems
LS600h/LS600hL_EE(OM50G20E)
■Conditions that may trigger the system even if there is no danger of a collision
In any of the following situations where the frontal area of the radar sensor is inter-
rupted, the radar sensor may detect possibility of a frontal collision and the system
may be activated.
●When passing by an oncoming vehicle in a curve or a turn to the right or the left.
●When rapidly approaching an obstacle ahead (e.g. preceding vehicle, toll gate bar-
rier, etc.)
●When there is a structural object (billboard, low ceiling, fluorescent light, etc.)
above the uphill road ahead
●When driving on a narrow road or through under a low overhead structure (bridge,
tunnel, fly-under, etc.)
●When driving on an uneven road surface
●When there is a metal object, bump, or protrusion on the road surface
●When vehicle front part is raised or lowered depending on loading conditions
●When the direction of radar sensor is misaligned by strong impact applied on an
area around the radar sensor, etc.
●When there is an obstacle (guard rail, etc.) by the roadside at the entrance to a
curve
●When the front of your vehicle is pointing upwards (caused by putting a heavy load
in the trunk etc.)
●When driving through an area filled with steam or smoke
When the system is activated in the situatio ns described above, there is also a possi-
bility that the seat belts will retract quickly and the brakes may be applied with a force
greater than normal. When the seat belt is locked in the retracted position, stop the
vehicle in a safe place, release the seat belt and refasten it.
■Obstacles not detected
The radar sensor cannot detect plastic obstacles such as traffic cones. There may
also be occasions when the sensor cannot detect pedestrians, animals, bicycles,
motorcycles, trees, or snowdrifts.
■A camera sensor cannot detect obstacles in the following situations:
●A camera sensor is directly receiving intense light, such as sunlight.
●Visibility is poor because of bad weather or other reasons.
●The sensor temperature is extremely high.
●The headlights are not turned on in darkness such as at night or in a tunnel.

3534-5. Using the driving support systems
4
Driving
LS600h/LS600hL_EE(OM50G20E)
■Situations in which the pre-crash safety 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 end 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-crash safety system
When a malfunction occurs due to sensor contamination, etc. that results in the sen-
sors being unable to detect obstacles, the pre-crash safety system will be automati-
cally 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-crash safety system warning light will flash and warning messages will be
displayed. ( P. 557, 563)