2013 Lexus IS300h Owner's Manual

2954-5. Using the driving support systems
4
Driving
IS300h_EE(OM53B95E)
If the vehicle gets stuck in fresh snow or mud, the TRC and VSC systems
may reduce power from the hybrid system to the wheels. Pressing VSC
OFF switch to turn the system off may make it easier for you to rock the
vehicle in order to free it.
Turning off the TRC system only
To turn the TRC system off,
quickly press and release the
switch.
The “TRC OFF” will be shown
on the multi-information display.
Press the switch again to turn the
system back on.
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-informa-
tion display.
*
Press the switch again to turn the
systems back on.
*: On vehicles with pre-crash safety system, pre-crash brake assist and pre-
crash braking will also be disabled. The pre-crash safety system warning
light will come on and the message will be shown on the multi-information
display. (P. 299)
Disabling the TRC/VSC systems

2964-5. Using the driving support systems
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When the 12-volt battery is disconnected
The steering wheel may move from its straight forward position, but this will be
corrected automatically when driving.
Sounds and vibrations caused by the ABS, brake assist, TRC, VSC, 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 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.
EPS operation sound
When the steering wheel is operated, a motor 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 sys-
tem off and then on again will automatically reactivate the TRC/VSC systems.
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 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 over-
heating 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 normal within 10 minutes.

2974-5. Using the driving support systems
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IS300h_EE(OM53B95E)
Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will oper-
ate:
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 off in any of the following situations:
The shift lever is moved to P or N.
The accelerator pedal is depressed.
The parking brake is engaged.
Approximately 2 seconds elapse after the brake pedal is released.
Operating conditions of emergency brake signal
When the following three conditions are met, 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 vehicle deceleration that this is a sudden braking operation.
Automatic system cancelation of emergency brake signal
The emergency brake signal will turn off 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.

2984-5. Using the driving support systems
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CAUTION
The ABS does not operate effectively when
The limits of tire gripping performance have been exceeded (such as exces-
sively 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 vehicle’s stopping distance. Always
maintain a safe distance from the vehicle in front of you, especially in the fol-
lowing situations:
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
TRC may not operate effectively when
Directional control and power may not be achievable while driving on slippery
road surfaces, even if the TRC system is operating.
Drive the vehicle carefully in conditions where stability and power may be lost.
Hill- start assist control does not operate effectively when
Do not overly rely on hill-start assist control. Hill-start assist control may not
operate effectively on steep inclines and roads covered with ice.
Unlike the parking brake, hill-start assist control is not intended to hold the
vehicle stationary for an extended period of time. Do not attempt to use hill-
start assist control to hold the vehicle on an incline, as doing so may lead to an
accident.
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 TRC/VSC systems are turned off
Be especially careful and drive at a speed appropriate to the road conditions. As
these are the systems to ensure vehicle stability and driving force, do not turn
the TRC/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 recom-
mended tire inflation pressure level.
The ABS, TRC and VSC systems will not function correctly if different tires
are installed on the vehicle.
Contact any authorized Lexus dealer or repairer, or another duly qualified and
equipped professional 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.

2994-5. Using the driving support systems
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Driving
IS300h_EE(OM53B95E)
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 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. The system may not warn the driver using a warn-
ing light, warning display and buzzer when the system detects and
judges braking operations.
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 reduce the collision speed.
Suspension control (vehicles with Adaptive Variable Suspension Sys-
tem)
PCS (Pre-Crash Safety system)

: If equipped
When the radar sensor detects the possibility of a frontal collision, brakes
are automatically engaged to lessen impact as well as vehicle damage.
The pre-crash safety system can be turned on and off as necessary by
operating the switch. (P. 301)

3004-5. Using the driving support systems
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When the system determines that there is a high possibility of a frontal
collision, the operation of Adaptive Variable Suspension System (P.
294) optimally controls the damping force of the shock absorber.

3014-5. Using the driving support systems
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Driving
IS300h_EE(OM53B95E)
Enabled
Disabled
The pre-crash safety system warning
light comes on when pre-crash
safety system is disabled.
The radar sensor detects vehicles or
other obstacles on or near the road
ahead and determines whether a
collision is imminent based on the
position, speed, and heading of the
obstacles.
Disabling pre-crash safety system
1
2
Radar sensor

3024-5. Using the driving support systems
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The pre-crash safety system is operational when
The PCS OFF switch is not pressed and the following conditions are met:
Pre-crash warning:
• Vehicle speed is greater than about 15 km/h (10 mph).
• The speed at which your vehicle is approaching the obstacle or the vehicle
running ahead of you is greater than about 15 km/h (10 mph).
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
running ahead of you is greater than about 30 km/h (19 mph).
• The brake pedal is depressed.
Pre-crash braking:
• The VSC 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
running ahead of you is greater than about 15 km/h (10 mph).
Suspension control (vehicles with Adaptive Variable Suspension System):
• Vehicle speed is greater than about 5 km/h (4 mph).
• The speed at which your vehicle is approaching the obstacle or the vehicle
running ahead of you is greater than about 30 km/h (19 mph).
Conditions that may trigger the system even if there is no danger of a collision
When there is an object by the roadside at the entrance to a curve
When passing an oncoming vehicle on a curve
When driving over a narrow iron bridge
When there is a metal object on the road surface
When driving on an uneven road surface
When passing an oncoming vehicle on a left-turn (left-hand drive vehicles) or
right-turn (right-hand drive vehicles)
When your vehicle rapidly closes on the vehicle in front
When a grade separation/interchange, sign, billboard, or other structure appears
to be directly in the vehicle’s line of travel
When there is a metal plate in the road in front of the vehicle on a downhill
slope
When climbing a steep hill causes an overhead billboard or other metallic struc-
ture to appear directly in the vehicle’s line of travel
When driving under an overpass
When an extreme change in vehicle height occurs
When passing through certain toll gates
When passing through a tunnel
When the radar sensor moves off position due to its surrounding area being sub-
jected to a strong impact
When the system is activated in the situations described above, there is also a
possibility that the brakes will be applied with a force greater than normal.