wheel Lexus IS250 2008 Owner's Guide

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2-1. Driving procedures
08_IS350/250_U_(L/O_0708)
CAUTION
●Do not turn the engine off while driving.
The brake booster system will not operate properly if the engine is not running.
●Use engine braking (downshift) to maintain a safe speed when driving down a
steep hill.
Using the brakes continuously may cause the brakes to overheat and lose effec-
tiveness. (→P. 1 2 3 )
●When stopped on an inclined surface, use the brake pedal and parking brake to
prevent the vehicle from rolling backward or forward and causing an accident.
●Do not adjust the position of the steering wheel, the seat, or the inside or outside
rear view mirrors while driving.
Doing so may result in a loss of vehicle control that can cause accidents that may
result in death or serious injury.
●Always check that all passengers' arms, heads or other parts of their bodies are
not outside the vehicle, as this may result in death or serious injury.
●Do not drive the vehicle off-road.
This is not a AWD vehicle designed for real off-road driving. Proceed with all due
caution if it becomes unavoidable to drive off-road.
●Do not drive across river crossings or through other bodies of water.
This may cause electric/electronic components to short circuit, damage the
engine or cause other serious damage to the vehicle.
●Do not drive in excess of the speed limit. Even if the legal speed limit permits it, do
not drive over 85 mph (140 km/h) unless your vehicle has high-speed capability
tires. Driving over 85 mph (140 km/h) may result in tire failure, loss of control and
possible injury. Be sure to consult a tire dealer to determine whether the tires on
your vehicle are high-speed capability tires or not before driving at such speeds.
■When driving on slippery road surfaces
●Sudden braking, acceleration and steering may cause tire slippage and reduce
your ability to control the vehicle, resulting in an accident.
●Sudden changes in engine speed, such as engine braking caused by up-shifting
or down-shifting, may cause the vehicle to skid, resulting in an accident.
●After driving through a puddle, lightly depress the brake pedal to make sure that
the brakes are functioning properly. Wet brake pads may prevent the brakes from
functioning properly. If the brakes on only one side are wet and not functioning
properly, steering control may be affected, resulting in an accident.

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2-1. Driving procedures
2
When driving
08_IS350/250_U_(L/O_0708)
CAUTION
●The brake system consists of 2 individual hydraulic systems: if one of the systems
fails, the other will still operate. In this case, the brake pedal should be depressed
more firmly than usual and braking distance becomes longer.
Do not drive your vehicle with only a single brake system. Have your brakes fixed
immediately.
■If the vehicle becomes stuck or bogged (AWD models)
Do not spin the wheels recklessly when any of the tires is up in the air, or stuck in
sand or mud, etc. This may damage the drive system components or propel the
vehicle forward (or in another direction) and cause an accident.
NOTICE
■When driving the vehicle
●With manual transmission vehicles, do not rest your foot on the clutch pedal while
driving.
Doing so may cause clutch trouble.
●With manual transmission vehicles, do not use any gears other than the first gear
when starting off and moving forward.
Doing so may damage the clutch.
●With automatic transmission vehicles, do not use the accelerator pedal or
depress accelerator and brake pedals together to hold the vehicle on a hill.
●With manual transmission vehicles, do not use the clutch to hold the vehicle when
stopping on an uphill grade.
■When parking the vehicle
With automatic transmission vehicles, always put the shift lever in P. Failure to do so
may cause the vehicle to move or the vehicle may accelerate suddenly if the accel-
erator pedal is accidentally depressed.
■Avoiding damage to vehicle parts
●Do not turn the steering wheel fully in either direction and hold it there for a long
time.
Doing so may damage the power steering motor.
●When driving over bumps in the road, drive as slowly as possible to avoid damag-
ing the wheels, underside of the vehicle, etc.

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2-1. Driving procedures
08_IS350/250_U_(L/O_0708)
NOTICE
■If you hear a squealing or scraping noise (brake pad wear limit indicators)
Have your Lexus dealer check and replace the brake pads as soon as possible.
The rotor damage can result if the pads are not replaced when needed.
Front brake only: Moderate levels of the brake pad and disc wear allow enhanced
front braking power. As a result, the discs may wear more quickly than conventional
brake discs. Therefore, when replacing the brake pads, Lexus recommends that you
also have the thickness of the discs measured.
It is dangerous to drive the vehicle when the wear limits of the brake pads and/or
that of the brake discs are exceeded.
■If you get a flat tire while driving
A flat or damaged tire may cause the following situations. Hold the steering wheel
firmly and gradually press the brake pedal to slow down the vehicle.
●It may be difficult to control your vehicle.
●The vehicle will make abnormal sounds.
●The vehicle will behave abnormally.
Replace a flat tire with a new one. ( →P. 3 8 4 )
■When encountering flooded roads
Do not drive on a road that has flooded after heavy rain etc. Doing so may cause the
following serious damage to the vehicle.
●Engine stalling
●Short in electrical components
●Engine damage caused by water immersion
In the event that you drive on a flooded road and the vehicle is flooded, be sure to
have your Lexus dealer check the following.
●Brake function
●Changes in quantity and quality of oil and fluid used for the engine, transmission,
differential, etc.
●Lubricant condition for the propeller shaft, bearings and suspension joints (where
possible) and the function of all joints, bearings, etc.

163
2-4. Using other driving systems
2
When driving
08_IS350/250_U_(L/O_0708)
CAUTION
■Conditions under which the vehicle-to-vehicle distance control may not function
correctly
Apply the brakes as necessary in the following 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
■To ensure the radar sensor functions correctly
Do not do the following to the sensor or grille cover as doing so may cause the sen-
sor not to function correctly and could result in an accident.
●Stick or attach anything to them
●Leave them dirty
●Disassemble, subject them to strong shocks
●Modify or paint them
●Replace them with non-genuine parts

170
2-4. Using other driving systems
08_IS350/250_U_(L/O_0708)
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)
Restrains the vehicle from slipping when driving on slick road surfaces or
in the event of sudden braking.
■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 when swerving suddenly or turning on
slippery road surfaces.
■TRAC (Traction Control)
Maintains drive power and prevents the rear wheels (2WD models) or all
wheels (AWD models) from spinning wh en starting the vehicle or acceler-
ating on slippery roads.
■ Hill-start assist control (vehicles with an automatic transmission)
Prevents the vehicle from rolling backwards when starting on an incline or
slippery slope.
■EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn
the steering wheel.

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2-4. Using other driving systems
2
When driving
08_IS350/250_U_(L/O_0708)
When the VSC/TRAC/hill-start assist control systems are operatingIf the vehicle is in danger of slip-
ping, rolling backwards when
starting on an incline, or if the rear
wheels (2WD) or 4 wheels
(AWD) 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.
■VDIM (Vehicle Dynamics Integrated Management) (IS350)
Provides integrated control of the ABS, brake assist, TRAC, VSC, hill-start
assist control, 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. 1 76

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2-4. Using other driving systems
08_IS350/250_U_(L/O_0708)
To disable TRAC and/or 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.
The slip indicator light should come
on.
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.
The slip indicator light and “VSC
OFF” indicator light should come
on.
Push the button again to turn the
system back on.

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2-4. Using other driving systems
08_IS350/250_U_(L/O_0708)
■Hill-start assist control is operational when
●The shift lever is in the D or S position.
●The brake pedal is not depressed.
■Reduced effectiveness of EPS
The effectiveness of EPS 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 engine OFF. The system should return to normal within
10 minutes.
CAUTION
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded.
●The vehicle hydroplanes while driving at high speed on the wet or slick road.
■Stopping distance when the ABS is operating will exceed that of normal condi-
tions
The ABS is not designed to shorten the vehicle’s stopping distance. Always main-
tain a safe distance from the vehicle in front of you 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 roads with uneven roads

175
2-4. Using other driving systems
2
When driving
08_IS350/250_U_(L/O_0708)
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.
■If hill-start assist control does not operate effectively
(vehicles with an automatic transmission)
The hill-start assist control may not operate effectively on steep inclines and roads
covered in ice.
■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
there 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 same 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.

183
2-5. Driving information
2
When driving
08_IS350/250_U_(L/O_0708)
Winter driving tips
Carry out the necessary preparations and inspections before driving the
vehicle in winter. Always drive the vehicle in a manner appropriate to the
prevailing weather conditions.
■Pre-winter preparations
● Use fluids that are appropriate to the prevailing outside tempera-
tures.
• Engine oil
• Engine coolant
• Washer fluid
• Have a service technician inspect the level and specific gravity
of battery electrolyte.
● Have the vehicle fitted with four snow tires or purchase a set of
tire chains for the rear tires.
Ensure that all tires are the specified size and the same brand, and that
chains match the size of the tires.
■Before driving the vehicle
Perform the following according to the driving conditions.
● Do not try to forcibly open a window or move a wiper that is fro-
zen. Pour warm water over the frozen area to melt the ice. Wipe
away the water immediately to prevent it from freezing.
● To ensure proper operation of the climate control system fan,
remove any snow that has accumulated on the air inlet vents in
front of the windshield.
● Remove any ice that has accumulated on the vehicle chassis.
● Periodically check for and remove any excess ice or snow that
may have accumulated in the wheel well or on the brakes.