
3024-5. Using the driving support systems
IS300h_EE(OM53D89E)
■Dynamic radar cruise control can be set when
●The shift lever is in D or range 4 or higher of S has been selected.
●Range 4 or higher of D has been selected by using the paddle shift switch.
●Vehicle speed is above approximately 50 km/h (30 mph).
■Accelerating after setting the vehicle speed
The vehicle can accelerate by operating the accelerator pedal. After accelerating, the set speed resumes. However, du ring vehicle-to-vehicle distance control mode, the vehi-
cle speed may decrease below the set speed in order to maintain the distance to the pre-
ceding vehicle.
■Automatic cancelation of vehicle-to-vehicle distance control mode
Vehicle-to-vehicle distance control mode is automatically canceled in the following situ-
ations.
●Actual vehicle speed falls below approximately 40 km/h (25 mph).
●VSC is activated.
●TRC is activated for a period of time.
●When the VSC or TRC system is turned off by pressing the VSC OFF switch.
●When snow mode is set.
●The sensor cannot detect correctly because it is covered in some way.
●Pre-collision braking is activated.
If vehicle-to-vehicle distance control mode is automatically canceled for any other rea-
son, there may be a malfunction in the syst em. Contact any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer.

3034-5. Using the driving support systems
4
Driving
IS300h_EE(OM53D89E)
■Automatic cancelation of constant speed control mode
Constant speed control mode is automatica lly canceled in the following situations:
●Actual vehicle speed is more than approximately 16 km/h (10 mph) below the set vehi-
cle speed.
●Actual vehicle speed falls below approximately 40 km/h (25 mph).
●VSC is activated.
●TRC is activated for a period of time.
●When the VSC or TRC system is turned off by pressing the VSC OFF switch.
●Pre-collision braking is activated.
If constant speed control mode is automati cally canceled for any other reason, there may
be a malfunction in the syst em. Contact any authorized Lexus retailer or Lexus autho- rized repairer, or an y reliable repairer.
■Warning messages and buzzers for dynamic radar cruise control
Warning messages and buzzers are used to indicate a system malfunction or to inform the driver of the need for ca ution while driving. If a warning message is shown on the
multi-information display, read the message and follow the instructions.
■When the sensor may not be correctly detecting the vehicle ahead
In the case of the following and depending on the conditions, operate the brake pedal
when deceleration of the system is insuff icient or operate the accelerator pedal when
acceleration is required. As the sensor may not be able to correctly detect these types of vehicles, the approach
warning ( P. 300) may not be activated.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving in the same lane
●Vehicles with small rear ends (trailers with no load on board, etc.)
●Motorcycles traveling in the same lane
●When water or snow thrown up by the surrounding vehicles hinders the detecting of
the sensor

3074-5. Using the driving support systems
4
Driving
IS300h_EE(OM53D89E)
■Cruise control can be set when
●The shift lever is in D or range 4 or higher of S has been selected.
●Range 4 or higher of D has been selected by using the paddle shift.
●Vehicle speed is above approximately 40 km/h (25 mph).
■Accelerating after setting the vehicle speed
●The vehicle can be accelerated normally. After acceleration, the set speed resumes.
●Even without canceling the cruise control, the set speed can be increased by first accel-
erating the vehicle to the desired speed and then pushing the lever down to set the new
speed.
■Automatic cruise control cancelation
Cruise control will stop maintaining the vehi cle speed in any of the following situations.
●Actual vehicle speed falls more than approximately 16 km/h (10 mph) below the preset vehicle speed.
At this time, the memorized set speed is not retained.
●Actual vehicle speed is below approximately 40 km/h (25 mph).
●VSC is activated.
●TRC is activated for a period of time.
●When the VSC or TRC system is turned off by pressing the VSC OFF switch.
■If the warning message for the cruise control is shown on the multi-information display
Press the “ON/OFF” button once to deactiv ate the system, and then press the button
again to reactivate the system. If the cruise control speed cannot be set or if the cruise control cancels immediately after
being activated, there may be a malfunction in the cruise control system. Have the vehi-
cle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reli- able repairer.

3524-5. Using the driving support systems
IS300h_EE(OM53D89E)
◆ECB (Electronically Controlled Brake System)
The electronically controlled system generates braking force corresponding
to the brake operation
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the br akes are applied suddenly, or if the
brakes are applied while drivin g 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 contro l skidding when swerving suddenly or turning on
slippery road surfaces.
◆VSC+ (Vehicle Stability Control+)
Provides cooperative control of the ABS, TRC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery road sur-
faces by controlling steering performance.
◆TRC (Traction Control)
Helps to maintain drive power and pr event the drive wheels from spinning
when starting the vehicle or accelerating on slippery roads
◆Hill-start assist control
Helps to reduce the backward movement of the vehicle when starting on an
uphill
◆EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn the
steering wheel.
Driving assist systems
To help enhance driving safety and pe rformance, the following systems oper-
ate automatically in response to various driving situations. Be aware, however,
that these systems are supplementary and should not be relied upon too heav-
ily when operating the vehicle.

3534-5. Using the driving support systems
4
Driving
IS300h_EE(OM53D89E)
◆Adaptive Variable Suspension System (if equipped)
Controls the damping force of the shoc k absorber of each wheel according to
the road and driving conditions, helpin g achieve a comfortable ride, excellent
driveability and a high level of stability.
If SPORT S+ mode is selected using the driving mode select switch, the
damping force will become more suitable for sporty driving. (P. 349)
◆VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the AB S, brake assist, TRC, VSC, hill-start
assist control, and EPS systems
Helps to maintain vehicle stability when swerving on slippery road surfaces by
controlling the brakes and hybrid system output
◆Emergency brake signal
When the brakes are applied suddenly, the stop lights automatically flash to
alert the vehicle behind.
The slip indicator light will flash while
the TRC/VSC/ABS systems are oper-
ating.
When the TRC/VSC/ABS systems are operating

3544-5. Using the driving support systems
IS300h_EE(OM53D89E)
If the vehicle gets stuck in mud, dirt or snow, the TRC system may reduce power
from the hybrid system to the wheels. Pressing to turn the system off may
make it easier for you to rock the vehicle in order to free it.
To turn the TRC system off, quickly
press and release .
The “Traction Control Turned Off” will
be shown on the multi-information dis-
play. Press again to turn the sys-
tem back on.
■Turning off both TRC and VSC systems
To turn the TRC and VSC systems off, pr ess and hold for more than 3 seconds
while the vehicle is stopped.
The VSC OFF indicator light will come on an d the “Traction Control Turned Off” will be
shown on the multi-information display.*
Press again to turn the system back on.
*: On vehicles with pre-collision system, pre-co llision brake assist and pre-collision brak-
ing will also be disabled. The pre-collision sy stem warning light will come on and the
message will be shown on the multi-information display. (P. 581)
■When the message is displayed on the multi-information display showing that TRC has
been disabled even if the VSC OFF switch has not been pressed
TRC cannot be operated. Contact any authorized Lexus retailer or Lexus authorized
repairer, or any reliable repairer.
Disabling the TRC system

3554-5. Using the driving support systems
4
Driving
IS300h_EE(OM53D89E)
■Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will operate:
●The shift lever is in a position other than P or N (when starting off forward/backward on
an upward incline)
●The vehicle is stopped
●The accelerator pedal is not depressed
●The parking brake is not engaged
■Automatic system cancelation of hill-start assist control
The hill-start assist control will turn of f in any of the following situations:
●The shift lever is shifted to P or N
●The accelerator pedal is depressed
●The parking brake is engaged
●Approximately 2 seconds elapse after the brake pedal is released
■When the 12-volt battery is disconnected
The steering wheel may move fr om its straight forward position, but this will be corrected
automatically when driving.
■Sounds and vibrations caused by the ABS, brake assist, TRC, VSC and hill-start assist control 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 also after the vehicle comes to a stop.
■ECB operating sound
ECB operating sound may be heard in the followi ng cases, but it does not indicate that a
malfunction has occurred.
●Operating sound heard from the engine compartment when the brake pedal is oper- ated.
●Motor sound of the brake system heard from the front part of the vehicle when the
driver’s door is opened.
●Operating sound heard from the engine compartment when one or two minutes
passed after the stop of the hybrid system.
■EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be heard.
This does not indicate a malfunction.

3564-5. Using the driving support systems
IS300h_EE(OM53D89E)
■Automatic reactivation of TRC and VSC systems
After turning the TRC and VSC systems off, the systems will be automatically re-enabled in the following situations:
●When the power switch is turned off
●If only the TRC system is tu rned off, the TRC will turn on when vehicle speed increases If both the TRC and VSC syst ems are turned off, automatic re-enabling will not occur
when vehicle speed increases.
■Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from overheating
when there is frequent steering input over an extended period of time. The steering
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 nor-
mal within 10 minutes.
■Operating conditions of emergency brake signal
When the following three conditions are me t, the emergency brake signal will operate:
●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 vehi-
cle deceleration that this is a sudden braking operation
■Automatic system cancelation of emergency brake signal
The emergency brake signal will turn of f 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 operation