Lexus 2013 IS250 Owner's Manual page 541

526
8-2. Steps to take in an emergency

Stopping the engine
Shift the shift lever to P and press the engine switch as you normally do when
stopping the engine.

Replacing the key battery
As the above procedure is a temporary measure, it is recommended that the elec-
tronic key battery be replaced immediately when the battery is depleted. (P.
441)

Alarm (if equipped)
Using the mechanical key to lock the doors will not set the alarm system.
If a door is unlocked using the mechanical key when the alarm system is set, the
alarm may be triggered.

Changing engine switch modes
Release the brake pedal and press the engine switch in step
The engine does not start and modes will be changed each time the switch is
pressed. (P. 191)

When the electronic key does not work properly

Make sure that the smart entry & start system has not been deactivated in the
customization setting. If it is off, turn the function on.
(Customizable features P. 549)

Check if battery-saving mode is set. If it is set, cancel the function. (P. 131)
IS250_EE(OM53B11E)
3 above.