Page 121 of 462

120
2-1. Driving procedures
08_IS350/250_U_(L/O_0708)
■If the engine does not start
The engine immobilizer system may not have been deactivated. (
→P. 7 2 )
■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, the “ENGINE START STOP” switch will automatically turn OFF.
■Electronic key battery depletion
→P. 2 8
■When the electronic key battery is fully discharged
→P. 3 2 5
■Conditions affecting operation
→P. 2 6
■Note for the entry function
→P. 2 9
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.
■Caution when driving
Do not touch the “ENGINE START STOP” switch while driving.
Pressing and holding the “ENGINE START STOP” switch will stop the engine,
which may lead to an unexpected accident.
Page 122 of 462
121
2-1. Driving procedures
2
When driving
08_IS350/250_U_(L/O_0708)
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.
Page 123 of 462
122
2-1. Driving procedures
08_IS350/250_U_(L/O_0708)
Automatic Transmission (if equipped)
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.
Page 124 of 462
123
2-1. Driving procedures
2
When driving
08_IS350/250_U_(L/O_0708)
■Shift position uses
*1: To improve fuel consumption and reduce noises, set the shift lever in the D
position for normal driving.
*2: Selecting shift ranges using S mode re stricts the upper limit of the possible
gear ranges, controls engine brakin g forces, and prevents unnecessary
upshifting.
■ 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.
Shift positionFunction
PParking the vehicle or starting the engine
RReversing
NNeutral
DNormal driving*1
SS mode driving*2 (→P. 1 2 4 )
Page 125 of 462

124
2-1. Driving procedures
08_IS350/250_U_(L/O_0708)
Changing shift ranges in S modeShift the shift lever to the S position and operate the shift lever or shift
paddle switch. Upshifting
Downshifting
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. 125)
■ Shift ranges and their functions
A lower shift range will provide greater engine braking forces than a higher shift
range.
Shift rangeFunction
6Automatically selecting gears between 1 and 6
according to vehicle speed and driving conditions.
5Automatically selecting gears between 1 and 5
according to vehicle speed and driving conditions.
4Automatically selecting gears between 1 and 4
according to vehicle speed and driving conditions.
3Automatically selecting gears between 1 and 3
according to vehicle speed and driving conditions.
2Automatically selecting gears between 1 and 2
according to vehicle speed and driving conditions.
1Setting the gear at 1.
Page 126 of 462

125
2-1. Driving procedures
2
When driving
08_IS350/250_U_(L/O_0708)
■Gear position display when driving in S mode
The current gear is displayed on the multi-information display. (
→P. 1 4 2 )
■Downshifting restrictions warning buzzer (in the S mode)
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 or dynamic radar cruise control sys-
tem
The engine brake will not operate in the S mode, even when downshifting to 5 or 4.
(
→P. 152, 155)
■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. 3 9 2
■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. (Shift-
ing the shift lever to the S position cancels the function.)
Page 127 of 462
126
2-1. Driving procedures
08_IS350/250_U_(L/O_0708)
Manual Transmission (if equipped)
Snow modeThe snow mode is used for accel-
erating and driving on slippery
road surfaces, such as on snow.
Push the switch once more to
return to normal mode.
■Shifting the shift lever
Fully depress the clutch pedal
before operating the shift lever,
and then release it slowly.
■ Shifting the shift lever into R
Shift the shift lever into the R
position while lifting up the ring
section.
Page 128 of 462
127
2-1. Driving procedures
2
When driving
08_IS350/250_U_(L/O_0708)
■Maximum downshifting speed
Adhere to the downshifting speeds in the following table in order to prevent over-
revving the engine. mph (km/h)
Shift positionMaximum speed
133 (54)
256 (90)
383 (134)
4108 (172)