Page 497 of 584

4978-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
One of the following may be the cause of the problem:
●One or both of the battery terminals may be disconnected.
●The battery may be discharged. (P. 5 0 2 )
●There may be a malfunction in the steering lock system.
Contact your Lexus dealer if the problem cannot be repaired, or if repair procedures
are unknown.
When the engine does not start, the following steps can be used as an interim
measure to start the engine if the engine switch is functioning normally:
Set the parking brake.
Shift the shift lever to P.
Turn the engine switch to ACCESSORY mode.
Press and hold the engine switch for about 15 seconds while depressing the
brake pedal firmly.
Even if the engine can be started using the above steps, the system may be mal-
functioning. Have the vehicle inspected by your Lexus dealer.
The starter motor does not turn over, the interior lights and headlights
do not turn on, or the horn does not sound.
Emergency start function
1
2
3
4
Page 504 of 584

5048-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
■Starting the engine when the battery is discharged
The engine cannot be started by push-starting.
■To prevent battery discharge
●Turn off the headlights and the audio system while the engine is off.
●Turn off any unnecessary electrical components when the vehicle is running at a low
speed for an extended period, such as in heavy traffic.
■Charging the battery
The electricity stored in the battery will discharge gradually even when the vehicle is not
in use, due to natural discharge and the draining effects of certain electrical appliances. If
the vehicle is left for a long time, the battery may discharge, and the engine may be
unable to start. (The battery recharges automatically during driving.)
■When recharging or replacing the battery
●Make sure that the key is not inside the vehicle when recharging or replacing the bat-
tery. The key may be locked in the vehicle if the alarm is activated. ( P. 7 2 )
●In some cases, it may not be possible to unlock the doors using the smart access system
with push-button start when the battery is discharged. Use the wireless remote control
or the mechanical key to lock or unlock the doors.
●The engine may not start on the first attempt after the battery has recharged but will
start normally after the second attempt. This is not a malfunction.
●The engine switch mode is memorized by the vehicle. When the battery is recon-
nected, the system will return to the mode it was in before the battery was discharged.
Before disconnecting the battery, turn the engine switch off.
If you are unsure what mode the engine switch was in before the battery discharged, be
especially careful when reconnecting the battery.
Page 516 of 584
5169-1. Specifications
IS350/250_U (OM53C50U)
■Spark plug
Cooling system
IS250IS350
Capacity 11.1 qt. (10.5 L, 9.2 Imp. qt.) 9.8 qt. (9.3 L, 8.2 Imp. qt.)
Coolant type
Use either of the following:
• “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-based non-silicate,
non-amine, non-nitrite, and non-borate coolant with long-
life hybrid organic acid technology
Do not use plain water alone.
Ignition system
Make DENSO FK20HBR11
Gap0.043 in. (1.1 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.
Electrical system
Battery
Open voltage at 68F
(20 C):12.6 12.8 V Fully charged
12.2
12.4 V Half charged
11.8
12.0 V Discharged
(Check the voltage 20 minutes after the engine and all
lights are turned off.)
Charging rates5 A max.
Page 521 of 584
5219-1. Specifications
9
Vehicle specifications
IS350/250_U (OM53C50U)
Light bulbs*1
Light bulbsBulb No.WTy p e
Exterior
Discharge headlights*235A
Front turn signal lights7444NA28 /8B
Rear turn signal lights21B
Back-up lights92116C
Outer foot lights5C
Interior
Door courtesy lights1685C
Vanity lights8C
Interior light8C
Pe r s o n a l l i g h t s8C
Footwell lights1943.8C
Trunk light5C
A: D4S discharge bulbsB: Wedge base bulbs (amber)
C: Wedge base bulbs (clear)
*1: Light bulbs not listed in this table are LED bulbs.
*2: If equipped
Page 542 of 584

5429-2. Customization
IS350/250_U (OM53C50U)
■Tu r n s i g n a l l e v e r ( P. 1 7 0 )
*1: After flashing the turn signal lights when turn ing left or right while this function is off
and the turn signal lever is moved to the fi rst position in the direction of the flashing
light, the turn signal lights can be selected to be flashing or off.
*2: The turn signal lights keep flashing if the tu rn signal lever is moved to the first position
in the direction of flashing light.
*3: The turn signal lights will be off if the turn signal lever is moved to the first position in
the direction of flashing light.
■Automatic light control system ( P. 1 7 3 )
FunctionDefault settingCustomized setting
The number of times the
turn signal lights flash auto-
matically when the turn sig-
nal lever is moved to the first
position during a lane
change
*1
3
5
——O7
Off*2
Off*3
123
FunctionDefault settingCustomized setting
Light sensor sensitivityStandard-2 to 2O—O
Time elapsed before head-
lights automatically turn off
after doors are closed
30 seconds
Off
O—O60 seconds
90 seconds
Welcome light illumination
controlOnOff——O
123
Page 543 of 584
5439-2. Customization
9
Vehicle specifications
IS350/250_U (OM53C50U)
■Lights (P. 1 7 3 )
*: U.S.A. only
■Intuitive parking assist*1 ( P. 2 1 4 )
*1: If equipped
*2: When intuitive parking assist is operating.
■Automatic air conditioning system ( P. 3 5 8 )
FunctionDefault settingCustomized setting
Daytime running light sys-
tem*OnOffO—O
123
FunctionDefault settingCustomized setting
Detection distance of the
front center sensorFarNearO—O
Detection distance of the
rear center sensorFarNearO—O
Buzzer volume31 to 5O—O
Display setting*2All sensors dis-
playedDisplay offO—O
123
FunctionDefault settingCustomized setting
A/C Auto switch operationOnOffO—O
123
Page 544 of 584
5449-2. Customization
IS350/250_U (OM53C50U)
■Illumination ( P. 3 6 8 )
■Seat belt reminder ( P. 4 6 7 )
FunctionDefault settingCustomized setting
Time elapsed before the
interior lights turn off15 seconds
Off
O—O7. 5 s e c o n d s
30 seconds
Operation after the engine
switch is turned offOnOff——O
Operation when the doors
are unlockedOnOff——O
Operation when you
approach the vehicle with
the electronic key on your
person
OnOff——O
Inside door handle lightsOnOff——O
Time elapsed before the
outer foot lights turn off15 seconds
Off
O—O7. 5 s e c o n d s
30 seconds
Operation of the outer foot
lights when you approach
the vehicle with the elec-
tronic key on your person
OnOff——O
Operation of the outer foot
lights when the doors are
unlocked with the power
door lock switch
OnOff——O
123
FunctionDefault settingCustomized setting
Vehicle speed linked seat
belt reminder buzzerOnOff——O
123
Page 566 of 584

566Alphabetical index
IS350/250_U (OM53C50U)
Back-up lightsReplacing light bulbs ......................... 451
Wattage ................................................... 521
Battery....................................................... 420 Battery checking ................................420
If the vehicle battery is discharged.................................... 502
Preparing and checking before winter ................................................... 260
Warning light ...................................... 466
Bluetooth
®
Audio system .........................................317
Hands-free system (for cellular phone) ......................... 319
Bottle holders ......................................... 372
Brake Fluid............................................................ 419
Parking brake......................................... 172
Warning light ...................................... 466
Brake assist ............................................. 240
Break-in tips.............................................. 147
Brightness control Instrument panel light control .........84
BSM (Blind Spot Monitor)................ 252 Care................................................ 396, 399
Aluminum wheels .............................. 397
Exterior ................................................... 396
Interior ..................................................... 399
Seat belts............................................... 400
Cargo capacity ....................................... 156
Cargo hooks ...........................................374
CD player................................................ 295
Chains ......................................................... 261
Child restraint system ............................54 Booster seats, definition .................... 55
Booster seats, installation ................. 64
Convertible seats, definition ........... 55
Convertible seats, installation........... 61
Front passenger occupant classification system..........................47
Infant seats, definition.......................... 55
Infant seats, installation......................... 61
Installing CRS with LATCH anchors ..................... 59
Installing CRS with seat belts ........... 61
Installing CRS with top tether strap......................... 65
BC