Lexus 2013 IS250 Owner's Manual page 544

4
Start the engine of the second vehicle. Increase the engine speed
slightly and maintain at that level for approximately 5 minutes to
recharge the battery of your vehicle.
5
Open and close any of the doors of your vehicle with the engine switch
off.
6
Maintain the engine speed of the second vehicle and start the engine of
your vehicle by turning the engine switch to IGNITION ON mode.
7
Once the vehicle's engine has started, remove the jumper cables in the
exact reverse order from which they were connected.
Once the engine starts, have the vehicle inspected at any authorized
Lexus dealer or repairer, or another duly qualified and equipped profes-
sional as soon as possible.

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 vehi-
cle is not in use, due to natural discharge and the draining effects of certain elec-
trical 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

For vehicles with an alarm: Make sure that the key is not inside the vehicle
when recharging or replacing the battery. The key may be locked in the vehicle
if the alarm is activated. (P. 85)

In some cases, it may not be possible to unlock the doors using the smart entry
& start system 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
reconnected, 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 dis-
charged, be especially careful when reconnecting the battery.
IS250_EE(OM53B11E)
8-2. Steps to take in an emergency
529
8