
1484-1. Before driving
IS350/250_U (OM53C50U)
CAUTION
Observe the following precautions.
Failure to do so may result in death or serious injury.
■When starting the vehicle
Always keep your foot on the brake pedal while stopped with the engine running. This
prevents the vehicle from creeping.
■When driving the vehicle
●Do not drive if you are unfamiliar with th e location of the brake and accelerator ped-
als to avoid depressing the wrong pedal.
• Accidentally depressing the accelerator pedal instead of the brake pedal will result in sudden acceleration that may lead to an accident.
• When backing up, you may twist your body around, leading to a difficulty in oper- ating the pedals. Make sure to operate the pedals properly.
• Make sure to keep a correct driving posture even when moving the vehicle only slightly. This allows you to depress the brake and accelerator pedals properly.
• Depress the brake pedal using your right foot. Depressing the brake pedal using
your left foot may delay response in an emergency, resulting in an accident.
●Do not drive the vehicle over or stop the vehicle near flammable materials.
The exhaust system and exhaust gases can be extremely hot. These hot parts may
cause a fire if there is any flammable material nearby.
●During normal driving, do not turn off the engine. 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.
However, in the event of an emergency, such as if it becomes impossible to stop the
vehicle in the normal way: →P. 4 5 7
●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 effective-
ness. ( →P. 1 6 4 )
●Do not adjust the positions 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.
●Always check that all passengers’ arms, heads or other parts of their body are not
outside 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.

1524-1. Before driving
IS350/250_U (OM53C50U)
NOTICE
■When driving the vehicle
●Do not depress the accelerator and brake pedals at the same time during driving, as
this may restrain driving torque.
●Do not use the accelerator pedal or depress the accelerator and brake pedals at the
same time to hold the vehicle on a hill.
■When parking the vehicle
Always shift the shift lever to P. Failure to do so may cause the vehicle to move or the
vehicle may accelerate suddenly if the accelerator pedal is accidentally depressed.
■Avoiding damage to vehicle parts
●Do not turn the steering wheel fully in either direction and hold it there for an
extended period of time.
Doing so may damage the power steering motor.
●When driving over bumps in the road, drive as slowly as possible to avoid damaging
the wheels, underside of the vehicle, etc.
■If you get a flat tire while driving
A flat or damaged tire may cause the follo wing situations. Hold the steering wheel
firmly and gradually depress the brake pedal to slow down the vehicle.
●It may be difficult to control your vehicle.
●The vehicle will make abnormal sounds or vibrations.
●The vehicle will lean abnormally.
Information on what to do in case of a flat tire ( →P. 4 8 6 )
■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 models), differential, etc.
●Lubricant condition for the propeller shaft, bearings and suspension joints (where
possible), and the function of all joints, bearings, etc.

1614-2. Driving procedures
4
Driving
IS350/250_U (OM53C50U)
■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 ti me when the engine is not running.
■Electronic key battery depletion
→P. 1 0 1
■Conditions affecting operation
→P. 116
■Notes for the entry function
→P. 117
■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 ma y not have been deactivated. (→P. 6 9 )
Contact your Lexus dealer.
■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 func tion. 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 repe atedly 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.

2064-5. Using the driving support systems
IS350/250_U (OM53C50U)
CAUTION
■Situations unsuitable for dynamic radar cruise control
Do not use dynamic radar cruise control in any of the following situations.
Doing so may result in inappropriate speed control and could cause an accident result-
ing in death or serious injury.
●In heavy traffic
●On roads with sharp bends
●On winding roads
●On slippery roads, such as those covered with rain, ice or snow
●On steep downhills, or where there are su dden changes between sharp up and down
gradients
Vehicle speed may exceed the set speed when driving down a steep hill.
●At entrances to expressways
●When weather conditions are bad enough that they may prevent the sensors from
functioning correctly (fog, snow, sandstorm, heavy rain, etc.)
●When an approach warning buzzer is heard often
●During emergency towing
■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. 201) 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 ve hicle-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 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

2124-5. Using the driving support systems
IS350/250_U (OM53C50U)
●When driving on roads that are branching or merging
●When driving on a road surface that is wet du e 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 syst em malfunction or to inform the driver of
the need for caution while driving. ( →P. 4 76 )
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 fo r understanding his/her surroundings, for
operating the steering wheel to correct th e 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

2224-5. Using the driving support systems
IS350/250_U (OM53C50U)
■Using the system
Use any of the following modes.
●Estimated course line display mode ( →P. 2 2 4 )
Estimated course lines are dis-
played which move in accor-
dance with the operation of the
steering wheel.
●Parking assist guide line display mode ( →P. 2 2 6 )
The steering wheel return points
(parking assist guide lines) are
displayed.
●Distance guide line display mode
Distance guide lines only are dis-
played.

2244-5. Using the driving support systems
IS350/250_U (OM53C50U)
■Screen description
Estimated course line display mode
Vehicle center guide line
The line indicates the estimated vehicle center on the ground.
Vehicle width guide line
The line indicates a guide path when the vehicle is being backed straight up.
The displayed width is wider than the actual vehicle width.
The line aligns with the estimated course lines when the steering wheel is straight.
Estimated course lines
The lines show an estimated course when the steering wheel is turned.
Distance guide line
The line moves, together with the estimated course lines, in sync with the steering
wheel. The line shows points approximately 1.5 ft. (0.5 m) (red) and approximately
3 ft. (1 m) (yellow) from the center of the edge of the bumper.
Distance guide line
The line shows distance behind the vehicle, a point approximately 1.5 ft. (0.5 m)
(blue) from the edge of the bumper.
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2254-5. Using the driving support systems
4
Driving
IS350/250_U (OM53C50U)
■Parking operation
When parking in a space which is in the reverse direction to the space
described in the procedure below, the steering directions will be reversed.Shift the shift position to R posi-
tion.
Turn the steering wheel so that
the estimated course lines are
within the parking space, and
back up slowly.Pa r k i n g s p a c e
Estimated course lines
When the rear position of the
vehicle has entered the parking
space, turn the steering wheel so
that the vehicle width guide lines
are within the left and right divid-
ing lines of the parking space. Vehicle width guide line
Once the vehicle width guide lines and the parking space lines are parallel,
straighten the steering wheel and back up slowly until the vehicle has com-
pletely entered the parking space.
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