2011 Lexus IS250 engine

136
2-1. Driving procedures
IS350/250_U
■Changing “ENGINE STAR T STOP” switch mode
Modes can be changed by pressing the “ENGINE START STOP”
switch with the brake pedal (vehicles with an automatic transmission)
or clutch pedal (vehicles with a manual transmission) released. (The
mode changes each time the switch is pressed.)
OFF*
The emergency flashers can be
used.
ACCESSORY mode
Some electrical components
such as the audio system can be
used.
The “ENGINE START STOP”
switch indicator turns amber.
IGNITION ON mode
All electrical components can
be used.
The “ENGINE START STOP”
switch indicator turns amber.
*: If the shift lever is in a positionother than P when turning off
the engine, the “ENGINE
START STOP” switch will be
turned to ACCESSORY mode,
not to OFF. (vehicles with auto-
matic transmission)

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.

139
2-1. Driving procedures
2
When driving
IS350/250_U
Automatic transmission∗
Select a shift position appropriate for the driving conditions.
■Shifting the shift lever
While the “ENGINE START STOP” switch is in IGNITION
ON mode, depress the brake pedal and move the shift lever.
■ Shift position uses
*: To improve fuel consumption and reduce noises, set the shift lever in the D
position for normal driving.
Shift positionFunction
PParking the vehicle or starting the engine
RReversing
NNeutral
DNormal driving*
SS mode driving ( →P. 1 4 2 )
∗: If equipped

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2-1. Driving procedures
IS350/250_U
Selecting shift ranges in the D position
To drive using temporary shift range selection, operate the “-” shift paddle
switch. The shift range can then be selected by operating the “-” and “+”
shift paddle switches. Changing the shift range allows restriction of the
upper limit of the gears to be used , preventing unnecessary upshifting
and enabling the level of engine braking force to be selected.
Higher shift range
Lower shift range
The selected shift range, from 1 to
6, will be displayed in the meter
cluster.
To return to normal D position
driving, the “+” shift paddle switch
must be held down for a period of
time.
■ Selecting a driving mode
The following patterns can be selected to suit current driving and
operating conditions.
Power mode
For powerful acceleration
and driving in mountainous
regions.
Normal mode
Snow mode
For accelerating and driving
on slippery road surfaces,
such as on snow.
Press “SNOW”
to return to nor-
mal mode.

142
2-1. Driving procedures
IS350/250_U
Changing shift ranges in S modeTo enter S mode, shift the shift lever to the S position. The shift range can
then be selected by operating the “-” and “+” shift paddle switches or the
shift lever. Changing the shift range a llows restriction of the upper limit of
the gears to be used, preventing unnecessary upshifting and enabling the
level of engine braking force to be selected.
Higher shift range
Lower shift range
The selected shift range, from 1 to
6, will be displayed in the meter
cluster.
The initial shift range in S mode is automatically set to 5 or 4 according to
vehicle speed. However, the initial shift range may be set to 3 or 2 if the
AI-SHIFT has operated while the sh ift lever was in the D position.
(→ P. 1 4 4 )
■ Shift ranges and their functions
→ P. 1 4 1

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2-1. Driving procedures
2
When driving
IS350/250_U
■When the “-” shift paddle switch is operated in the D position
When the “-” shift paddle switch is operated in the D position, a shift range will be
automatically selected. The highest gear of the first shift range will be one gear
lower than the gear in use during normal D position driving.
■Automatic deactivation of shift range selection in the D position
Shift range selection in the D position will be deactivated in the following situations:
●When the vehicle comes to a stop
●When range 6 is selected and the accelerator pedal is depressed
●If the accelerator pedal is depressed for more than a certain period of time
■To protect automatic transmission
A function is adopted that automatically selects a higher shift range when the fluid
temperature is high.
■Gear position display when driving
The current gear is displayed on the multi-information display. (→P. 1 6 3 )
■Downshifting restrictions warning buzzer
To help ensure safety and driving performance, downshifting operation may some-
times be restricted. In some circumstances, downshifting may not be possible even
when the shift lever or shift paddle switch is operated. (The warning buzzer will
sound twice.)
■When driving with the cruise control system
Engine braking will not occur during shift range selection in the D position or S
mode, even when downshifting to range 5 or 4. ( →P. 1 7 5 )
■Snow mode automatic deactivation
Snow mode is automatically deactivated if the “ENGINE START STOP” switch is
turned off after driving in snow mode.
■If the shift lever cannot be shifted from P
→P. 4 9 1

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2-1. Driving procedures
IS350/250_U
■If does not come on even after shifting the shift lever to S
This may indicate a malfunction in the automatic transmission system. Have the
vehicle inspected by your Lexus dealer immediately.
(In this situation, the vehicle will operate as if the shift lever is in D.)
■AI-SHIFT
The AI-SHIFT automatically shifts the gear to the optimal position according to the
driver performance and driving conditions.
The AI-SHIFT automatically operates when the shift lever is in the D position. How-
ever, operating the “-” shift paddle switch will restrict the function’s operation. (Shift-
ing the shift lever to the S position cancels the function.)
While in power mode, the engine speed may stay high while depressing the accel-
erator pedal and may remain high after releasing the accelerator pedal. This does
not indicate a malfunction.
CAUTION
■When driving on slippery road surfaces
Be careful of downshifting and sudden acceleration, as this could result in the vehi-
cle skidding to the side or spinning.