steering Lexus IS250 2011 Service Manual

133
2-1. Driving procedures
2
When driving
IS350/250_U
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.
Rotor damage can result if the pads are not replaced when needed.
Front brake only: Moderate levels of 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
those 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.
Information on what to do in case of a flat tire ( →P. 4 8 1 )
■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,
transfer (AWD vehicles), differential, etc.
●Lubricant condition for the propeller shaft (AWD vehicles), bearings and suspen-
sion joints (where possible) and the function of all joints, bearings, etc.

137
2-1. Driving procedures
2
When driving
IS350/250_U
■If the engine does not start
The engine immobilizer system may not have been deactivated. (→P. 8 5 )
■When the steering lock cannot be released
■When the “ENGINE START STOP” switch indicator flashes in amber
The system may be malfunctioning. Have the vehicle inspected by your Lexus
dealer immediately.
■Auto power off function
If the vehicle is left in ACCESSORY mode for more than an hour with the shift lever
in P (vehicles with an automatic transmission), the “ENGINE START STOP” switch
will automatically turn OFF.
■Electronic key battery depletion
→P. 3 4
■When the electronic key battery is fully discharged
→P. 4 2 1
■Conditions affecting operation
→P. 3 2
■Note for the entry function
→P. 3 5 The “ENGINE START STOP” switch indica-
tor will flash in green and a message will be
shown on the multi-information display. Press
the “ENGINE START STOP” switch again
while turning the steering wheel left and right.

138
2-1. Driving procedures
IS350/250_U
CAUTION
■When starting the engine
Always start the engine while sitting in the driver’s seat. Do not press the accelera-
tor while starting the engine under any circumstances.
Doing so may cause an accident resulting in death or serious injury.
■Stopping the engine in an emergency
If you want to stop the engine in an emergency while driving the vehicle, push and
hold the “ENGINE START STOP” switch for more than 3 seconds.
However, do not touch the “ENGINE START STOP” switch while driving except in
an emergency. Turning the engine off while driving will not cause loss of steering or
braking control, but the power assist to these systems will be lost. This will make it
more difficult to steer and brake, so you should pull over and stop the vehicle as
soon as it is safe to do so.
NOTICE
■To prevent battery discharge
Do not leave the “ENGINE START STOP” switch in ACCESSORY or IGNITION
ON mode for long periods without the engine running.
■When starting the engine
●Do not race a cold engine.
●If the engine becomes difficult to start or stalls frequently, have the engine
checked immediately.

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2-1. Driving procedures
IS350/250_U
Horn
■After adjusting the steering wheel (vehicles with manually adjustable type steer-
ing wheel)
Make sure that the steering wheel is securely locked.
The horn may not sound if the steering wheel is not securely locked. (→P. 6 7 )
To sound the horn, press on or
close to the mark.

185
2-4. Using other driving systems
2
When driving
IS350/250_U
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)
Helps to prevent wheel lock when the brakes are applied suddenly, or if
the brakes are applied while driving on a slippery road surface.
■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)
Helps to prevent the vehicle from rolling backward 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.

186
2-4. Using other driving systems
IS350/250_U
When the VSC/TRAC/hill-start assist control systems are operating
The slip indicator light flashes to
indicate that the VSC/TRAC/hill-
start assist control systems have
been engaged.
The stop lights and high mounted
stoplight turn on when the hill-start
assist control system is operating.
■VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, brake assist, TRAC, VSC, hill-start
assist control, and EPS systems.
Helps to maintain vehicle stability when swerving on slippery road sur-
faces by controlling the brakes, engine output and steering assist.

188
2-4. Using other driving systems
IS350/250_U
■Automatic reactivation of the TRAC/VSC systems
If the TRAC/VSC systems are turned off, re-starting the engine 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, TRAC and hill-start
assist control systems
●A sound may be heard from the engine compartment if the brake pedal is
depressed repeatedly 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 when the ABS is activated.
• The brake pedal may move down slightly after the ABS is activated.

189
2-4. Using other driving systems
2
When driving
IS350/250_U
■Hill-start assist control is operational when
●The shift lever is in the D or S position.
●The brake pedal is not depressed.
●The vehicle rolls backward.
■EPS operation sound
When the steering wheel operates, a motor sound (whirring sound) may be heard.
This does not indicate a malfunction.
■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.
■If the slip indicator comes on
It may indicate a malfunction in the VSC, TRAC or hill start assist control function.
Contact your Lexus dealer.
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 may 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 surfaces

193
2-5. Driving information
2
When driving
IS350/250_U
CAUTION
■Things that must not be carried in the trunk
The following things may cause a fire if loaded in the trunk.
●Receptacles containing gasoline
●Aerosol cans
■Storage precautions
Observe the following precautions.
Failing to do so may result in death or serious injury.
●Do not place cargo or luggage in or on the following locations as the item may
get under the clutch, brake or accelerator pedal and prevent the pedals from
being depressed properly, block the driver's vision, or hit the driver or passen-
gers, causing an accident.
• The feet of the driver
• The front passenger or rear seats (when stacking items)
• The package tray
• The instrument panel
•The dashboard
●Secure all items in the occupant compartment, as they may shift and injure some-
one during sudden braking, sudden swerving or an accident.
■Capacity and distribution
●Do not exceed the maximum axle weight rating or the total vehicle weight rating.
●Even if the total load of occupant's weight and the cargo load is less than the total
load capacity, do not apply the load unevenly. Improper loading may cause dete-
rioration of steering or braking control which may cause death or serious injury.

194
2-5. Driving information
IS350/250_U
Vehicle load limits
■Total load capacity and seating capacity
These details are also described on the tire and loading information label.
( → P. 4 1 2 )
CAUTION
■Overloading the vehicle
Do not overload the vehicle.
It may not only cause damage to the tires, but also degrade steering and braking
ability, resulting in an accident.
Vehicle load limits include total load capacity, seating capacity, towing
capacity and cargo capacity.
■Total load capacity: 825 lb. (375 kg)
Total load capacity means the combined weight of occupants, cargo and
luggage.
■Seating capacity: 5 occupants (Front 2, Rear 3)
Seating capacity means the maximum number of occupants whose esti-
mated average weight is 150 lb. (68 kg) per person.
■Towing capacity
Lexus does not recommend towing a trailer with your vehicle.
■Cargo capacity
Cargo capacity may increase or decrease depending on the weight and
the number of occupants.