2015 Lexus IS250 suspension

2454-5. Using the driving support systems
4
Driving
IS350/250_U (OM53C50U)
CAUTION
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded (such as excessively
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 operat ing may exceed that of normal conditions
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 following 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
■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.
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 con-
trol 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 dr ive carefully. Reckless driving may cause an
accident. Exercise particular care when the indicator light flashes.
■When the TRAC/VSC systems are turned off
Be especially careful and drive at a speed appropriate to the road conditions. As these
are the systems to help ensure vehicle st ability and driving force, do not turn the
TRAC/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 recommended tire infla-
tion pressure level.
The ABS, TRAC and VSC systems will not function correctly if different tires are
installed on the vehicle.
Contact your Lexus dealer for further information when replacing tires or wheels.
■Handling of tires and the suspension
Using tires with any kind of problem or modi fying the suspension will affect the driving
assist systems, and may cause a system to malfunction.

2464-5. Using the driving support systems
IS350/250_U (OM53C50U)
◆ Pre-collision warning
When a high possibility of a frontal
collision is detected, the pre-colli-
sion system warning light flashes, a
buzzer sounds and a message is
shown on the multi-information dis-
play to urge the driver to take eva-
sive action.
◆Pre-collision 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 usin g a warning light, warning display and
buzzer when the system detects and judges braking operations.
◆Pre-collision 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 system deter-
mines that a collision is unavoidable, the brakes are automatically applied to
reduce the collision speed.
◆Suspension control (vehicles with Adaptive Variable Suspension System)
When the system determines that there is a high possibility of a frontal colli-
sion, the operation of Adaptive Variable Suspension System ( →P. 2 4 1 ) o p t i -
mally controls the damping force of the shock absorber.
PCS (Pre-Collision System)∗
∗
: If equipped
When the radar sensor detects the possibility of a frontal collision, brakes are
automatically engaged to lessen impa ct as well as vehicle damage.
The pre-collision system can be turned on and off as necessary by operating
the switch. ( →P. 2 4 7 )

2484-5. Using the driving support systems
IS350/250_U (OM53C50U)
■The pre-collision system is operational when
The PCS OFF switch is not pressed an d the following conditions are met:
●Pre-collision warning:
• Vehicle speed is greater than about 10 mph (15 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle running
ahead of you is greater than about 10 mph (15 km/h).
●Pre-collision brake assist:
• The VSC OFF switch is not pressed.
• Vehicle speed is greater than about 19 mph (30 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle runningahead of you is greater than about 19 mph (30 km/h).
• The brake pedal is depressed.
●Pre-collision braking:
• The VSC OFF switch is not pressed.
• Vehicle speed is greater than about 10 mph (15 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle running ahead of you is greater than about 10 mph (15 km/h).
●Suspension control (vehicles with Adaptive Variable Suspension System):
• Vehicle speed is greater than about 4 mph (5 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle runningahead of you is greater than about 19 mph (30 km/h).
■Conditions that may trigger the system ev en 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
●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 overhe ad billboard or other metallic structure 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 subjected
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.

4648-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
●Fluid leaks under the vehicle.
(Water dripping from the air conditioning after use is normal.)
●Flat-looking tires or uneven tire wear
●Engine coolant temperature gauge needle continually points higher than nor-
mal.
●Changes in exhaust sound
●Excessive tire squeal when cornering
●Strange noises related to the suspension system
●Pinging or other noises related to the engine
●Engine missing, stumbling or running roughly
●Appreciable loss of power
●Vehicle pulls heavily to one side when braking
●Vehicle pulls heavily to one side when driving on a level road
●Loss of brake effectiveness, spongy feeling, pedal almost touches the floor
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

4958-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
CAUTION
■When using the compact spare tire
●Remember that the compact spare tire provided is specifically designed for use with
your vehicle. Do not use your compact spare tire on another vehicle.
●Do not use more than one compact spare tires simultaneously.
●Replace the compact spare tire with a standard tire as soon as possible.
●Avoid sudden acceleration, abrupt steering, sudden braking and shifting operations
that cause sudden engine braking.
■When the compact spare tire is attached
The vehicle speed may not be correctly detected, and the following systems may not
operate correctly:
Also, not only can the following system not be utilized fully, but it may even negatively
affect the drive-train components:
• AWD system
■Speed limit when using the compact spare tire
Do not drive at speeds in excess of 50 mph (80 km/h) when a compact spare tire is
installed on the vehicle.
The compact spare tire is not designed for driving at high speeds. Failure to observe
this precaution may lead to an accident causing death or serious injury.
■After using the tools and jack
Before driving, make sure all the tools and jack are securely in place in their storage
location to reduce the possibility of personal injury during a collision or sudden brak-
ing.
NOTICE
■Driving with tire chains and the compact spare tire
Do not fit tire chains to the compact spare tire.
Tire chains may damage the vehicle body and adversely affect driving performance.
■When replacing the tires
When removing or fitting the wheels, tires or the tire pressure warning valve and trans-
mitter, contact your Lexus dealer as the tire pressure warning valve and transmitter
may be damaged if not handled correctly.
• ABS & Brake assist
•VSC
•TRAC
• Cruise control (if equipped)
• Dynamic radar cruise control (if equipped)
•PCS (if equipped)
•EPS • Adaptive Variable Suspension System
(if equipped)
• LDA (Lane Departure Alert) (if equipped)
• VGRS (if equipped)
• Rear view monitor system (if equipped)
• Intuitive parking assist (if equipped)
• Navigation system (if equipped)

557
10
For owners
IS350/250_U (OM53C50U)
ATTENTION
■Modification et mise au rebut des éléments du système de coussin gonflable SRS
Ne mettez pas votre véhicule au rebut et n’effectuez aucune des modifications suiva-
ntes sans consulter votre concessionnaire Lexus. Les coussins gonflables SRS risquent
de ne pas fonctionner correctement ou de se déployer (se gonfler) accidentellement,
provoquant ainsi des blessures graves, voire mortelles.
●Installation, retrait, démontage et réparation des coussins gonflables SRS
●Réparations, modifications, démontage ou remplacement du volant, du tableau de
bord, de la planche de bord, des sièges ou de leur garniture, des montants avant,
latéraux et arrière ou des rails latéraux de toit
●Réparations ou modifications des ailes avant, du pare-chocs avant ou des flancs de
l’habitacle
●Installation d'un protège-calandre (pare-buffle, pare-kangourou, etc.), de chasse-
neige, de treuils
●Modifications du système de suspension du véhicule
●Installation d’appareils électroniques, tels qu’une radio émetteur/récepteur ou un lec-
teur CD
●Aménagements du véhicule visant à permettre sa conduite par une personne
atteinte d’un handicap physique

564
IS350/250_U (OM53C50U)Alphabetical index
Alphabetical index
A/C ............................................................358
Air conditioning filter........................ 437
Automatic air conditioning system ................................................. 358
AAC disc ................................................. 295
ABS (Anti-lock Brake System)....... 240 Function ..................................................240
Warning light ...................................... 466
Accent color..............................................88
Adaptive Variable Suspension system .............................241
Air conditioning filter .......................... 437
Air conditioning system .....................358 Air conditioning filter........................ 437
Automatic air conditioning system ................................................. 358 Airbags .........................................................36
Airbag operating conditions .......... 44
Airbag precautions for your child ....................................... 39
Correct driving posture .................... 28
Curtain shield airbag operating conditions ....................... 44
Curtain shield airbag
precautions ............................................ 41
Front passenger occupant
classification system..........................47
General airbag precautions ........... 39
Locations of airbags............................ 36
Modification and disposal
of airbags............................................... 43
Side airbag operating
conditions ............................................. 44
Side airbag precautions .................... 39
Side and curtain shield airbags operating conditions ....................... 44
Side and curtain shield airbags precautions ......................... 39
SRS airbags ............................................. 36
SRS warning light .............................. 466
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