
3867-2. Steps to take in an emergency
6Open and close any of the doors of 
your vehicle with the power switch 
off.
7 Maintain the engine speed of the 
second vehicle and start the hybrid 
system of your vehicle by turning 
the power switch to ON mode.
8 Make sure the “READY” indicator 
comes on. If the indicator does not 
come on, contact your Lexus 
dealer.
9 Once the vehicle’s hybrid system 
has started, remove the jumper 
cables in the exact reverse order 
from which they were connected.
10 Close the exclusive jump starting 
terminal cover, and reinstall the fuse 
box cover to tits original position.
Once the hybrid system starts, have the 
vehicle inspected at your Lexus dealer as 
soon as possible.
■Starting the hybrid system when the 12-
volt battery is discharged
The hybrid system cannot be started by 
push-starting.
■To prevent 12-volt battery discharge
●Turn off the headlights and the audio sys-
tem while the hybrid system is stopped.
●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.423)
■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 12-volt battery that conforms to 
European regulations.
●Use a 12-volt battery that the case size is 
same as the previous one (LN2), 20 hour 
rate capacity (20HR) is equivalent 
(60Ah) or greater, and performance rat-
ing (CCA) is equivalent (345A) or 
greater.  

3877-2. Steps to take in an emergency
7
When trouble arises
• If the sizes differ, the 12-volt battery can-not be properly secured.
• 12-volt battery performance may  decrease and the hybrid system may not 
be able to start.
• 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 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 exchanging, firmly attach the fol-
lowing items to the exhaust hole of the 12-
volt battery.
• Use the exhaust hose that was attached 
to the 12-volt battery before exchanging.
• Use the exhaust hole plug included with  the 12-volt battery exchanged or the one 
installed on the battery prior to the 
exchange. (Depending on the 12-volt 
battery to be exchanged, the exhaust 
hole may be plugged.)
Exhaust hole plug
Exhaust hole
Exhaust hose
For details, consult your Lexus dealer.
A
B
C
WARNING
■When removing the 12-volt battery 
terminals
Always remove the negative (-) terminal 
first. If the positive (+) terminal contacts 
any metal in the surrounding area when 
the positive (+) terminal is removed, a 
spark may occur, leading to a fire in addi-
tion to electrical shocks and death or 
serious injury.
■Avoiding 12-volt battery fires or 
explosions
Observe the following precautions to 
prevent accidentally igniting the flamma-
ble gas that may be emitted from the 12-
volt battery:
●Make sure each jumper cable is con-
nected to the correct terminal and that 
it is not unintentiona lly in contact with 
any other than the intended terminal.
●Do not allow the other end of the 
jumper cable connected to the “+” ter-
minal to come into contact with any 
other parts or metal surfaces in the 
area, such as brackets or unpainted 
metal.
●Do not allow the + and - clamps of the 
jumper cables to come into contact 
with each other.
●Do not smoke, use matches, cigarette 
lighters or allow open flame near the 
12-volt battery.
■12-volt battery precautions
The 12-volt battery contains poisonous 
and corrosive acidic electrolyte, while 
related parts contain lead and lead com-
pounds. Observe the following precau-
tions when handling the 12-volt battery:
●When working with the 12-volt battery, 
always wear safety glasses and take 
care not to allow any 12-volt battery 
fluids (acid) to come into contact with 
skin, clothing or the vehicle body.
●Do not lean over the 12-volt battery. 

3887-2. Steps to take in an emergency
WARNING
●In the event that 12-volt battery fluid 
comes into contact with the skin or 
eyes, immediately wash the affected 
area with water and seek medical 
attention.
Place a wet sponge or cloth over the 
affected area until medical attention 
can be received.
●Always wash your hands after handling 
the 12-volt battery support, terminals, 
and other battery-related parts.
●Do not allow children near the 12-volt 
battery.
■After recharging the 12-volt battery
Have the 12-volt battery inspected at 
your Lexus dealer as soon as possible. If 
the 12-volt battery is deteriorating, con-
tinued use may cause the 12-volt battery 
to emit a malodorous gas, which may be 
detrimental to the health of passengers.
■When exchanging the 12-volt battery
●When the vent plug and indicator are 
close to the hold down clamp, the bat-
tery fluid (sulfuric acid) may leak.
●After exchanging, securely attach the 
exhaust hose and exhaust hole plug to 
the exhaust hole of the exchanged 12-
volt battery. If not  properly installed, 
gases (hydrogen) may leak into the 
vehicle interior, and there is the possi-
ble danger of the gas igniting and 
exploding.
NOTICE
■When handling jumper cables
When connecting the jumper cables, 
ensure that they do not become entan-
gled in the cooling fan or engine drive 
belt.
■To prevent damaging the vehicle
The exclusive jump starting terminal is to 
be used when charging the 12-volt bat-
tery from another vehicle in an emer-
gency. It cannot be used to jump start 
another vehicle.