Lexus LS500h, Manual, Page: 448 / 524

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7-2. Steps to take in an emergency
LS500h_OM_(U)_1810
● Turn off any unnecessary electrical com-
ponents when the vehicle is running at a
low speed for an extended period, such
as in heavy traffic.
■
When the 12-volt battery is removed or
discharged
●
Information stored in the ECU is cleared.
When the 12-volt battery is depleted,
have the vehicle inspected at your Lexus
dealer.
●
Some systems may require initialization.
(

P.494)
■ When removing the 12-volt battery ter-
minals
When the 12-volt battery terminals are
removed, the information stored in the
ECU is cleared. Before removing the
12-volt battery terminals, contact your
Lexus dealer.
■
Charging the 12-volt battery
The electricity stored in the 12-volt battery
will discharge gradually even when the
vehicle is not in use, due to natural dis-
charge and the draining effects of certain
electrical appliances. If the vehicle is left for
a long time, the 12-volt battery may dis-
charge, and the hybrid system may be
unable to start. (The 12-volt battery
recharges automatically while the hybrid
system is operating.)
■ When recharging or replacing the
12-volt battery
● In some cases, it may not be possible to
unlock the doors using the smart access
system with push-button start when the
12-volt battery is discharged. Use the
wireless remote control or the mechani-
cal key to lock or unlock the doors.
● The hybrid system may not start on the
first attempt after the 12-volt battery has
recharged but will start normally after the
second attempt. This is not a malfunction.
● The power switch mode is memorized by
the vehicle. When the 12-volt battery is
reconnected, the system will return to the
mode it was in before the 12-volt battery
was discharged. Before disconnecting
the 12-volt battery, turn the power switch
off.
If you are unsure what mode the power
switch was in before the 12-volt battery
discharged, be especially careful when
reconnecting the 12-volt battery.
■
When replacing the 12-volt battery
●
Use a Central Degassing type 12-volt
battery (European Regulations).
●
Use a 12-volt battery with the same case
size as the previous 12-volt battery and an
equivalent 20 hour rate capacity (20HR)
or greater.
• If the sizes differ, the 12-volt battery can-
not be properly secured.
• If the 20 hour rate capacity is low, even if
the time period where the vehicle is not
used is a short time, the 12-volt battery
may discharge and the hybrid system
may not be able to start.
●
Use a 12-volt battery with a handle. If a
12-volt battery without a handle is used,
removal is more difficult.
●
After replacing, firmly attach the follow-
ing items to the exhaust hole of the
12-volt battery.
• Use the exhaust hose that was attached
to the 12-volt battery before replacing
and confirm that it is firmly connected to
the hole section of the vehicle.
• Use the exhaust hole plug included with
the 12-volt battery replaced or the one
installed on the 12-volt battery prior to
the replacement. (Depending on the
12-volt battery to be replaced, the
exhaust hole may be plugged.)