Page 203 of 586

202
2-4. Using other driving systems
10_IS250C/350C_U
■Sensor detection information
●Certain vehicle conditions and the surrounding environment may affect the
ability of the sensor to correctly detect obstacles. Particular instances where this
may occur are listed below.
• There is dirt, snow or ice on the sensor.
• The sensor is frozen.
•The sensor is covered in any way.
• The vehicle is leaning considerably to one side.
• On an extremely bumpy road, on an incline, on gravel, or on grass.
• The vicinity of the vehicle is noisy due to vehicle horns, motorcycle engines,air brakes of large vehicles, or other loud noises producing ultrasonic waves.
• There is another vehicle equipped with parking assist sensors in the vicinity.
• The sensor is coated with a sheet of spray or heavy rain.
• The vehicle is equipped with a fender pole or wireless antenna.
• Towing eyelets are installed.
• The bumper or sensor receives a strong impact.
• The vehicle is approaching a tall or curved curb.
• In harsh sunlight or intense cold weather
In addition to the examples above, there are instances in which, because of their
shapes, signs and other objects may be judged by the sensor to be closer than they
are.
●The shape of the obstacle may prevent the sensor from detecting it. Pay particu-
lar attention to the following obstacles.
• Wires, fences, ropes etc.
• Cotton, snow and other materials that absorb radio waves
• Sharply-angled objects
• Low obstacles
• Tall obstacles with upper sections projecting outwards in the direction of your
vehicle
■When the display flashes and a message is displayed
→ P. 4 7 2
Page 206 of 586
205
2-4. Using other driving systems
2
When driving
10_IS250C/350C_U
When the VSC/TRAC systems are operatingIf the vehicle is in danger of slip-
ping, or if the rear wheels spin, the
slip indicator light flashes to indi-
cate that the VSC/TRAC systems
have been engaged.
A buzzer (intermittent) sounds to
indicate that VSC is operating.
■VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, brake assist, TRAC, VSC, and
EPS systems.
Maintains vehicle stability when swerving on slippery road surfaces by
controlling the brakes and engine output.
■PCS (Pre-Collision System) (if equipped)
→ P. 2 1 2
Page 207 of 586
206
2-4. Using other driving systems
10_IS250C/350C_U
To disable TRAC/VSCIf the vehicle gets stuck in fresh snow or mud, TRAC and VSC may
reduce power from the engine to the wheels. You may need to turn the
system off to enable you to rock the vehicle in order to free it.
■ Turning off TRAC
Quickly push and release the but-
ton to turn off TRAC.
A message will be shown on the
multi-information display.
Push the button again to turn the
system back on.
■Turning off TRAC and VSC
Push and hold the button for more
than 3 seconds while the vehicle is
stopped to turn off TRAC and
VSC.
A message will be shown on the
multi-information display and VSC
off indicator light will come on.
Push the button again to turn the
system back on.
Page 208 of 586

207
2-4. Using other driving systems
2
When driving
10_IS250C/350C_U
■Reactivation of the TRAC/VSC systems after turning off the engine
Turning off the engine after turning off the TRAC/VSC systems will automatically
reactivate them.
■Automatic TRAC reactivation
If only the TRAC system is turned off, the TRAC system will turn on when vehicle
speed increases.
■Automatic TRAC and VSC reactivation
If the TRAC and VSC systems are turned off, the systems will not turn on even when
vehicle speed increases.
■Sounds and vibrations caused by the ABS, brake assist, VSC and TRAC systems
●A sound may be heard from the engine compartment when the engine 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 slightly after the ABS is activated.
Page 210 of 586

209
2-4. Using other driving systems
2
When driving
10_IS250C/350C_U
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.
■When the VSC is activated
The slip indicator light flashes and a warning buzzer sounds. Always drive carefully.
Reckless driving may cause an accident. Exercise particular care when the indica-
tor light flashes and a buzzer sounds.
■When TRAC and VSC are off
Be especially careful and drive at a speed appropriate to the road conditions. As
these are systems to ensure vehicle stability and driving force, do not turn off TRAC
and VSC 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
pressure level.
The ABS and VSC systems will not function correctly if different tires are fitted on
the vehicle.
Contact your Lexus dealer for further information when replacing tires or wheels.
■Handling of tires and suspension
Using tires with any kind of problem or modifying the suspension will affect the driv-
ing assist systems, and may cause the system to malfunction.
Page 211 of 586

210
2-4. Using other driving systems
10_IS250C/350C_U
Hill-start assist control
■Hill-start assist control can be operated when
●The shift lever is in a position other than P (vehicles with automatic transmis-
sion).
●The parking brake is not applied.
●The accelerator pedal is not depressed.
■Hill-start assist control
●While hill-start assist control is operating, the brakes remain automatically
applied after the driver releases the brake pedal. The stop lights and the high
mounted stoplight turn on.
●Hill-start assist control operates for about 2 seconds after the brake pedal is
released.
●If the slip indicator does not flash and the buzzer does not sound when the brake
pedal is further depressed, slightly reduce the pressure on the brake pedal (do
not allow the vehicle to roll backward) and then firmly depress it again. If the sys-
tem still does not operate, check if the operating conditions explained above
have been met.
Hill-start assist control helps to prevent the vehicle from rolling backwards
when starting on an incline or slippery slope.
To engage hill-start assist con-
trol, further depress the brake
pedal when the vehicle is
stopped completely.
A buzzer will sound once to
indicate the system is activated.
The slip indicator will also start
flashing.
Page 215 of 586

214
2-4. Using other driving systems
10_IS250C/350C_U
●When your vehicle rapidly closes on the vehicle in front
●When your vehicle is skidding with the VSC system off
When the system is activated in the situations described above there is also a possi-
bility that the seat belts will retract quickly and the brakes will 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.
■Automatic cancelation of the pre-collision system
When a malfunction occurs due to sensor contamination, etc. that results in the
sensors being unable to detect obstacles, the pre-crash safety system will be auto-
matically disabled. In this case, the system will not activate even if there is a collision
risk.
■When there is a malfunction in the system
Warning lights and/or warning messages will turn on or flash. ( →P. 4 6 3 , 4 7 2 )
■Certification
For vehicles sold in U.S.A.
FCC ID: HYQDNMWR005
This device complies with Part 15 of the FCC Rules. Operation is subject to the fol-
lowing two conditions: (1) this device may not cause harmful interference, and (2)
this device must accept any interference received, including interference that may
cause undesired operation.
FCC WARNING
Changes or modifications not expressly approved by the party responsible for
compliance could void the user's authority to operate the equipment.
Radio frequency radiation exposure Information:
This equipment complies with FCC radiation exposure limits set forth for an uncon-
trolled environment.
This equipment should be installed and operated with minimum distance of 20 cm
between the radiator (antenna) and your body.
This transmitter must not be co-located or operating in conjunction with any other
antenna or transmitter.
Page 216 of 586

215
2-4. Using other driving systems
2
When driving
10_IS250C/350C_U
For vehicles sold in Canada
Operation is subject to the following two conditions: (1) this device may not cause
interference, and (2) this device must accept any interference, including interfer-
ence that may cause undesired operation of the device.
L’utilisation de ce dispositif est autoris
ée seulement aux deux conditions
suivantes: (1) il ne doit pas produire de brouillage et (2) l’utilisateur du dispositif
doit être prêt à accepter tout brouillage radioélectrique reçu, même si ce
brouillage est susceptible de compromettre le fonctionnement du dispositif.
CAUTION
■Limitations of the pre-collision system
Do not rely on the pre-collision system. Always drive safely, taking care to observe
your surroundings and checking for any obstacles or other road hazards.
■Handling the radar sensor
Observe the following to ensure the pre-collision system can function effectively.
●Keep the sensor and front grille clean at all times.
Clean the sensor and front grille with a soft cloth so you do not mark or damage
them.
●Do not subject the sensor or surrounding area to a strong impact.
If the sensor moves even slightly off position, the system may malfunction. If the
sensor or surrounding area are subject to a strong impact, always have the area
inspected and adjusted by a Lexus dealer.
●Do not disassemble the sensor.
●Do not attach accessories or stickers to the sensor, grille guard or surrounding
area.
●Do not modify or paint the sensor and grille.