2008 Lexus GS450h brake

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GS_HV_U
January 4, 2008 10:02 am
Cruising in vehicle-to-vehicle distance control mode This mode employs a radar sensor to detect the presence of vehicles
within 400 ft. (120 m) ahead and to judge the distance between your
vehicle and those vehicles.
Note that vehicle-to-vehicle distance will close when trave ling on long down-
hill slopes.
Example of constant speed cruising 
When there are no vehicles ahead
The vehicle travels at the speed set by the driver. The desired vehicle-to-vehi-
cle distance can also be set by oper ating the vehicle-to-vehicle distance
switch.
Example of deceleration cruising 
When the vehicle ahead is driving slower than the set speed
When a vehicle is detected running ahead of you, in the same lane, the sys-
tem automatically decelerates your vehicle. When a greater reduction in
vehicle speed is necessary, the system applies the brakes. A warning tone
warns you when the system cannot decelerate sufficiently to prevent your
vehicle from closing on the vehicle ahead.

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When driving
GS_HV_U
January 4, 2008 10:02 am
Example of follow-up cruising 
When following a vehicle driving slower than the set speed
The system continues follow-up cruising while adjusting for changes in the
speed of the vehicle ahead in order to maintain the vehicle-to-vehicle dis-
tance set by the driver.
Example of acceleration 
When there are no longer vehicles driving slower than the set speed in
the lane ahead
When the vehicle ahead of you executes a lane change, the system slowly
accelerates until the set vehicle speed is reached. The system then returns to
fixed speed cruising.
Approach warning
When your vehicle is too close to a vehicle ahead, and sufficient auto-
matic deceleration via the cruise cont rol is not possible, the display will
flash and buzzer will sound to alert th e driver. An example of this would
be if another driver cuts in front of you while you are following a vehicle.
Apply the brakes to ensure an appr opriate vehicle-to-vehicle distance.
■Warning lights and messages for dynamic radar cruise control
Warning lights, messages and buzzers are us ed to indicate a system malfunction or
to inform the driver of the need for caution while driving. ( P. 5 0 2 )
■Switching modes
The mode cannot be switched to constant speed control mode if vehicle-to-vehicle
distance control mode has been used. The mode also cannot be switched from
constant speed control to vehicle-to-vehic le control mode. Turn the system off by
pressing the “ON-OFF” button, and turn it on again.

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When driving
GS_HV_U
January 4, 2008 10:02 am
CAUTION
■Before using dynamic radar cruise control
Do not overly rely on vehicle-to-vehicle distance control.
Be aware of the set vehicle speed. If au tomatic deceleration/acceleration is not
appropriate, adjust the vehicle speed, as well as the distance between your vehicle
and vehicles ahead by applying the brakes, etc.
■To avoid operating the dynamic radar cruise control by mistake
Keep the “ON-OFF” button off when not in use.
■Situations unsuitable for dynamic radar cruise control
Do not use dynamic radar cruise contro l in any of the following situations.
Doing so may result in inappropriate cont rol of speed and could cause serious or
fatal accident.
●In heavy traffic
●On roads with sharp bends
●On winding roads
●On slippery roads, such as thos e covered with rain, ice or snow
●On steep downhills, where there are sudden changes between sharp up and
down gradients
Vehicle speed may exceed the set speed when driving down a steep hill.
●At entrances to expressways
●When weather conditions are bad enough that they may prevent the sensors
from functioning correctly (f og, snow, sandstorm, etc.)
●When the approach warning buzzer can be heard often

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January 4, 2008 10:02 am
CAUTION
■When the radar sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary when any of the following types of vehicles are in
front of you. 
As the sensor may not be able to correctly detect these types of vehicles, the prox-
imity alarm ( P. 509) will not be activated, and an accident may result.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving
●Vehicles with small rear ends (tra ilers with no load on board etc.)
●Motorcycles traveling in the same lane
■Conditions under which the vehicle-to-vehicle distance control may not function
correctly
Apply the brakes as necessary in the foll owing conditions as the radar sensor may
not be able to correctly detect vehicles ahead, and an accident may result.
●When water or snow thrown up by the surrounding vehicles hinders the function-
ing of the sensor
●When your vehicle is pointing upwards (caused by a heavy load in the trunk, etc.)
●When the road curves or when the lanes are narrow
●When steering wheel operation or your position in the lane is unstable
●When the vehicle ahead of you decelerates suddenly

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When driving
GS_HV_U
January 4, 2008 10:02 am
■When using the intuitive parking assist
●The sensors’ detection areas and reaction times are limited. When moving for-
ward or reversing, check the areas surrounding the vehicle (especially the sides
of the vehicle) for safety, and drive slowly, using the brake to control the vehicle’s
speed.
• The sensors’ detection areas are limited to the areas around the vehicle’s front and rear bumpers.
• Depending on the shape of the obstacle and other factors, the detection dis-
tance may shorten, or dete ction may be impossible.
• There will be a short delay between ob stacle detection and display. Even at
slow speeds, there is a possibility that the obstacle will come within 0.8 ft. (25
cm) of the vehicle before the display is shown and the warning beep sounds.
• Braking distance may differ according to the road conditions (rain, gravel
etc.).
• It might be difficult to hear beeps due to the volume of audio system or air flow noise of air conditioning system.
• For long obstacles such as walls, the obstacle warning may change as the obstacle gets closer.

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January 4, 2008 10:02 am
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 systems are supplementary and should not be relied
upon too heavily when operating the vehicle.
■ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly, or if
the brakes are applied while driving 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 wh en swerving suddenly or turning on
slippery road surfaces.
■ TRAC (Traction Control)
Maintains drive power and prevents the rear wheels from spinning when
starting the vehicle or accelerating on slippery roads.
■Hill-start assist control
Helps prevent the vehicle from rolling backwards when starting on an
incline or slippery slope. It operates for approximately 5 seconds at maxi-
mum.
■ 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)
Turns at smaller angles to main tain the stable vehicle posture.

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GS_HV_U
January 4, 2008 10:02 am
When the VSC/TRAC/hill-start assist control systems are operating
If the vehicle is in danger of slip-
ping, rolling backwards when
starting on an incli ne, or if the rear
wheels spin, the slip indicator light
flashes to indicate that the VSC/
TRAC/hill-start assist control sys-
tems have been engaged.
A buzzer (intermittent) sounds to
indicate that VSC is operating.
The stop lights and high mounted
stoplight turn on when the hill-start
assist control system is operating.
The slip indicator light flashes as
well when ABS is operating.
■ PCS (Pre-Collision System) (if equipped)
 P. 2 0 6
■VGRS (Variable Gear Ratio Steering)
Adjusts the wheel turning angle in accordance with the vehicle speed and
steering wheel movement.
■VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the AB S, VSC, TRAC, hill-start assist con-
trol, VGRS and EPS systems. 
Maintains vehicle stability when swerving on slippery road surfaces by
controlling the brakes, hybrid output, and the movement of the front
wheels.

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GS_HV_U
January 4, 2008 10:02 am
■Automatic reactivation of TRAC and VSC
Turning the “POWER” switch OFF after turning off the TRAC and VSC systems will
automatically re-enable them.
■Automatic TRAC reactivation
If only the TRAC system is turned off, the TRAC system will turn on when the vehi-
cle speed increases.
■Automatic TRAC and VSC reactivation
If the TRAC and VSC systems are turned off, the systems will not turn on even when
the vehicle speed increases.
■Sounds and vibrations caused by the A BS, brake assist, VSC, TRAC, hill-start
assist control and VGRS systems
●A sound may be heard from the engine compartment 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 operat-
ing. 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 s lightly after the ABS is activated.
■Hill-start assist control operating conditions
This system comes into operation under the following conditions after the brake
pedal has been depressed and the vehicle has come to a stop:
●The shift lever is in the “D” or “S”.
●The system has detected that the vehicle is moving backwards.