
1904-1. Before driving
IS250_EE(OM53C51E)
■Important points regarding stability
Vehicle movement resulting from uneven road surfaces and strong cross-
winds will affect handling. The vehicle may also be rocked by passing buses or
large trucks. Frequently check behind when moving alongside such vehicles.
As soon as such vehicle movement occurs, immediately start to decelerate
smoothly by slowly applying the brakes. Always steer the vehicle straight
ahead while braking.
■Passing other vehicles
Consider the total combined length of your vehicle and trailer and ensure that
the vehicle-to-vehicle distance is sufficient before executing lane changes.
■Transmission information
To maintain engine braking efficiency, when using engine braking when driv-
ing on a long steep downward grade, do not use the transmission in D. The
vehicle must be driven in gear shift position “4” in M mode. (→P. 2 0 0 )
■If the engine overheats
Towing a loaded trailer up a long, steep incline in temperatures exceeding
30°C (85°F) may result in the engine overheating. If the engine coolant tem-
perature gauge indicates that the engine is overheating, turn the air condition-
ing off immediately, leave the road and stop the vehicle in a safe place.
(→P. 5 3 1 )
■When parking the vehicle
Always place wheel chocks under the wheels of both the vehicle and trailer.
Firmly set the parking brake and shift the shift lever to P.

1944-2. Driving procedures
IS250_EE(OM53C51E)
■Auto power off function
If the vehicle is left in ACCESSORY mode for more than 20 minutes or IGNITION ON
mode (the engine is not running) for more than an hour with the shift lever in P, the engine
switch will automatically turn off. However, this function cannot entirely prevent battery
discharge. Do not leave the vehicle with the engine switch in ACCESSORY or IGNI-
TION ON mode for long periods of time when the engine is not running.
■Electronic key battery depletion
→P. 1 1 5
■Conditions affecting operation
→P. 1 3 2
■Notes for the entry function
→P. 1 3 3
■If the engine does not start
●Check that the shift lever is securely set in P. The engine may not start if the shift lever is
displaced out of P.
●The engine immobilizer system may not have been deactivated. (→P. 77)
Contact any authorized Lexus dealer or repairer, or another duly qualified and
equipped professional.
■Steering lock
After turning the engine switch off and opening and closing the doors, the steering wheel
will be locked due to the steering lock function. Operating the engine switch again auto-
matically cancels the steering lock.
■When the steering lock cannot be released
■Steering lock motor overheating prevention
To prevent the steering lock motor from overheating, operation of the motor may be sus-
pended if the engine is turned on and off repeatedly in a short period of time. In this case,
refrain from operating the engine switch. After about 10 seconds, the steering lock
motor will resume functioning. “Steering Lock active” will be displayed on the
multi-information display.
Check that the shift lever is in P. Press the
engine switch while turning the steering wheel
left and right.

2114-3. Operating the lights and wipers
4
Driving
IS250_EE(OM53C51E)
■The Automatic High Beam can be operated when
The engine switch is in IGNITION ON mode.
■Camera sensor detection information
●High beam may not be automatically turned off in the following situations:
• When oncoming vehicles suddenly appear from a curve
• When the vehicle is cut in front of by another vehicle
• When oncoming or preceding vehicles are hidden from sight due to repeated
curves, road dividers or roadside trees
●High beam may be turned off if an oncoming vehicle that is using fog lights without
using the headlights is detected.
●House lights, street lights, red traffic signals, and illuminated billboards or signs may
cause the high beam to turn off.
●The following factors may affect the amount of time taken to turn high beam on or off:
• The brightness of headlights, fog lights, and tail lights of oncoming and preceding
vehicles
• The movement and direction of oncoming and preceding vehicles
• When an oncoming or preceding vehicle only has operational lights on one side
• When an oncoming or preceding vehicle is a two-wheeled vehicle
• The condition of the road (gradient, curve, condition of the road surface etc.)
• The number of passengers and amount of luggage
●High beam may be turned on or off when unexpected by the driver.
●Small vehicles, such as bicycles, may not be detected.
●In the situations below, the system may not be able to correctly detect the surrounding
brightness levels, and may flash or expose nearby pedestrians to the high beam. There-
fore, you should consider turning the high beams on or off manually rather than relying
on the Automatic High Beam system.
• In bad weather (rain, snow, fog, sandstorms etc.)
• The windshield is obscured by fog, mist, ice, dirt etc.
• The windshield is cracked or damaged.
• The camera sensor is deformed or dirty.
• Surrounding brightness levels are equal to those of headlights, tail lights or fog lights.
• Vehicles ahead have headlights or tail lights that are either switched off, dirty, chang-
ing color, or have improperly adjusted aim.
• When driving through an area of intermittently changing brightness and darkness.
• When frequently and repeatedly driving ascending/descending roads, or roads with
rough, bumpy or uneven surfaces (such as stone-paved roads, gravel tracks etc.).
• When frequently and repeatedly taking curves or driving on a winding road.
• There is a highly reflective object ahead of the vehicle, such as a sign or a mirror.
• The vehicle’s headlights are damaged or dirty.
• The vehicle is listing or titling, due to a flat tire, a trailer being towed etc.
• The driver believes that the high beam may be causing problems or distress to other
drivers or pedestrians nearby.
• The vehicle is used in a territory in which vehicles travel on the opposite side of the
road of the country for which the vehicle is approved, for example using a vehicle
designed for right-hand traffic in a left-hand traffic territory, or vice versa.

2404-5. Using the driving support systems
IS250_EE(OM53C51E)
CAUTION
■When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary when any of the following types of vehicles are in front of
you.
As the sensor may not be able to correctly detect these types of vehicles, the approach
warning (→P. 234) will not be activated, and a fatal or serious accident may result.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving
●Vehicles with small rear ends (trailers with no load on board etc.)
●Motorcycles traveling in the same lane
■Conditions under which the vehicle-to-vehicle distance control may not function cor-
rectly
Apply the brakes as necessary in the following conditions as the radar sensor may not
be able to correctly detect vehicles ahead, and a fatal or serious accident may result:
●When water or snow thrown up by a the surrounding vehicles hinders the functioning
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
●When the vehicle ahead of you decelerates suddenly
■Handling the radar sensor
Observe the following to ensure the cruise control system can function effectively.
Otherwise, the system may not function correctly and could result in an accident.
●Keep the sensor and grille cover clean at all times.
Clean the sensor and grille cover 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 sen-
sor or surrounding area is subject to a strong impact, always have the area inspected
and adjusted by any authorized Lexus dealer or repairer, or another duly qualified
and equipped professional.
●Do not disassemble the sensor.
●Do not attach accessories or stickers to the sensor, grille cover or surrounding area.
●Do not modify or paint the sensor and grille cover.
●Do not replace them with non-genuine parts.

2454-5. Using the driving support systems
4
Driving
IS250_EE(OM53C51E)
●When sunlight or the headlights of oncoming vehicles are shining directly into the cam-
era lens
●When driving on roads that are branching or merging
●When driving on a road surface that is wet due to rain, previous rainfall, standing water,
etc.
●When the vehicle experiences strong up-and-down motion such as when driving on an
extremely rough road or on a seam in the pavement
●When headlight brightness at nighttime is reduced due to dirt on the lenses, or when
the headlights are misaligned
●When driving on winding roads or roads that are uneven
●When driving on rough or unpaved roads
■When changing the tires
Depending on the tires used, sufficient performance may not be maintainable.
■Warning messages for the LDA system
Warning messages are used to indicate a system malfunction or to inform the driver of
the need for caution while driving. (→P. 4 8 6 )
CAUTION
■Before using the LDA system
Do not rely solely on the LDA system. The LDA system does not drive the vehicle auto-
matically, nor does it reduce the amount of care you need to take. As such, the driver
must always assume full responsibility for understanding his/her surroundings, for
operating the steering wheel to correct the driving line, and for driving safely.
Inappropriate or negligent driving could lead to an accident.
■To avoid operating the LDA by mistake
Switch the LDA system off using the LDA switch when not in use.
■Situations unsuitable for LDA system
Do not use the LDA system in any of the following situations.
Otherwise, the system may not function correctly and could result in an accident.
●When driving with tire chains, a spare tire, or similar equipment
●When there are objects or structures along the roadside that might be misinterpreted
as lane markers (such as guardrails, a curb, reflector posts, etc.)
●When driving on snowy roads
●When pavement lane markers are difficult to see due to rain, snow, fog, sand dust etc.
●When there are visible lines on the pavement from road repairs, or if the remains of
old lane markers are still visible on the road
●When driving on a road with lane closures due to maintenance, or when driving in a
temporary lane

2614-5. Using the driving support systems
4
Driving
IS250_EE(OM53C51E)
CAUTION
■When using the rear view monitor system
The rear view monitor system is a supplemental device intended to assist the driver
when backing up. When backing up, be sure to check visually behind and all around
the vehicle before proceeding.
Observe the following precautions to avoid an accident that could result in death or
serious injuries.
●Never depend on the rear view monitor system entirely when backing up. The image
and the position of the guide lines displayed on the screen may differ from the actual
state.
Use caution, just as you would when backing up any vehicle.
●Be sure to back up slowly, depressing the brake pedal to control vehicle speed.
●The instructions given are only guidelines.
When and how much to turn the steering wheel will vary according to traffic condi-
tions, road surface conditions, vehicle condition, etc. when parking. It is necessary to
be fully aware of this before using the rear view monitor system.
●When parking, be sure to check that the parking space will accommodate your vehi-
cle before maneuvering into it.
●Do not use the rear view monitor system in the following cases:
• On icy or slick road surfaces, or in snow
• When using tire chains or the compact spare tire
• When the trunk lid is not closed completely
• On roads that are not flat or straight, such as curves or slopes.
●In low temperatures, the screen may darken or the image may become faint. The
image could distort when the vehicle is moving, or you may become unable to see the
image on the screen. Be sure to check direct visually and with the mirrors all around
the vehicle before proceeding.
●If the tire sizes are changed, the position of the fixed guide lines displayed on the
screen may change.
●The camera uses a special lens. The distances between objects and pedestrians that
appear in the image displayed on the screen will differ from the actual distances.
(→P. 2 5 6 )

2654-5. Using the driving support systems
4
Driving
IS250_EE(OM53C51E)
◆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
◆VSC+ (Vehicle Stability Control+)
Provides cooperative control of the ABS, TRC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery road sur-
faces by controlling steering performance.
◆TRC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from spinning
when starting the vehicle or accelerating on slippery roads
◆Hill-start assist control
Prevents the vehicle from rolling backward when starting on an incline or slip-
pery slope
◆EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn the
steering wheel
Driving assist systems
To help enhance driving safety and performance, the following systems oper-
ate 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.

2674-5. Using the driving support systems
4
Driving
IS250_EE(OM53C51E)
If the vehicle gets stuck in fresh snow or mud, the TRC and VSC systems may
reduce power from the engine 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 systems
off, press and hold the switch for
more than 3 seconds while the vehi-
cle is stopped.
The VSC OFF indicator light will
come on and the “TRC OFF” will be
shown on the multi-information dis-
play.
*
Press the switch again to turn the sys-
tems 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. 2 7 1 )
Disabling the TRC/VSC systems