
5418-2. Steps to take in an emergency
Owners Manual_USA_M42C01_en
8
When trouble arises
cannot be started, contact your Toy-
ota dealer.
■Stopping the EV system
Shift the shift position to P, set the 
parking brake and press the power 
switch as you no rmally do when 
stopping the EV system.
■Replacing the key battery
As the above proc edure is a tempo-
rary measure, it is recommended 
that the electronic key battery be 
replaced immediate ly when the bat-
tery is depleted. ( P.497)
■Alarm
If a door is unlocked using the 
mechanical key when the alarm sys-
tem is set, the alarm may be trig-
gered. ( P. 6 9 )
■Changing power switch modes
Release the brake pedal and press 
the power switch in step  3 above.
The EV system does not start and 
modes will be cha nged each time 
the switch is pressed. ( P.234)
If you have a set of jumper (or 
booster) cables and a second 
vehicle with a 12-volt battery, 
you can jump start your vehicle 
by following the steps below.
1Confirm that the electronic 
key is being carried.
When connecting the jumper (or 
booster) cables, depending on the 
situation, the alarm may activate 
and the doors locked. ( P. 7 0 )
2 Open the hood ( P.462).
3 Open the positive (+) battery 
terminal cover.
While pressing on the claw, open 
the cover as shown in the illustra-
If  the 12-volt batter y is 
discharged
The following procedures 
may be used to start the EV 
system if the vehicle’s 12-
volt battery is discharged.
You can also call your Toy-
ota dealer or a qualified 
repair shop.
Restarting the EV system 

5428-2. Steps to take in an emergency
Owners Manual_USA_M42C01_ention.
4
Connect a positive jumper cabl e clamp to   on your vehicle and 
connect the clamp on the other end of the positive cable to   on  
the second vehicle. Then, connect a negative cable clamp to   
on the second vehicle and connect the clamp at the other end of 
the negative cable to  .
Positive (+) battery terminal (your vehicle)
Positive (+) battery terminal (second vehicle)
Negative (-) battery term inal (second vehicle)
Solid, stationary, unpainted metallic point away from the batte ry 
and any moving parts as shown in the illustration
5 Start the engine of the sec-
ond vehicle. Increase the 
engine speed slightly and 
maintain at that level for  approximately 5 minutes to 
recharge the 12-volt battery 
of your vehicle. 

5438-2. Steps to take in an emergency
Owners Manual_USA_M42C01_en
8
When trouble arises
6 Open 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 EV system of your vehi-
cle by turning the power 
switch to ON.
8 Make sure the “READY” indi-
cator comes on. If the indica-
tor light does not come on, 
contact your Toyota dealer.
9 Once the EV system has 
started, remove the jumper 
cables in the exact reverse 
order from which they were 
connected.
10 Close the positive (+) battery 
terminal cover.
Once the EV system starts, 
have the vehicle inspected at 
your Toyota dealer as soon as 
possible.
■Starting the EV system when 
the 12-volt battery is dis-
charged
The EV system cannot be started by 
push-starting.
■To prevent 12-volt battery dis-
charge
●Turn off the headlights, the air 
conditioning system, the audio 
system, etc. while the EV system 
is off.
●Turn off any unnecessary electri-
cal components when the vehicle 
is running at a low speed for an 
extended period, such as in heavy 
traffic.
■Charging the 12-volt battery
The electricity stored in the 12-volt 
battery will discha rge gradually even 
when the vehicle i s not in use, due 
to natural dischar ge and the drain-
ing effects of certain electrical appli-
ances. If the vehicle is left for a long 
time, the 12-volt  battery may dis-
charge, and the  EV system may be 
unable to start. (The 12-volt battery 
recharges automatically while the 
EV system is operating.)
■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 Toyota dealer.
●In some cases, it may not be pos-
sible to unlock the doors using the 
smart key system when the 12-
volt battery is discharged. Use the 
wireless remote c ontrol or the 
mechanical key to lock or unlock 
the doors.
●The EV system may not start on 
the first attempt a fter the 12-volt 
battery has  recharged but will start 
normally after the second attempt. 
This is not a malfunction.
●The power switch mode is memo-
rized 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 discon-
necting 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 recon-
necting the 12-volt battery.
●If the 12-volt battery discharges, it 
may not be possible to shift the 
shift position to o ther positions. In 
this case, the vehicle cannot be 
towed without lifting both front 
wheels because the front wheels 
will be locked.
●The power back door (if equipped)  

5448-2. Steps to take in an emergency
Owners Manual_USA_M42C01_enmust be initialized. (
P.181)
■When replacing the 12-volt bat-
tery
●Use a 12-volt battery that con-
forms to European regulations.
●Use a 12-volt battery that the case 
size is same as the previous one 
(LN1), 20 hour rate capacity 
(20HR) is equiva lent (45Ah) or 
greater, and performance rating 
(CCA) is equivalent (286A) or 
greater.
• If the sizes differ, the 12-volt bat- tery cannot be properly secured.
• If an improper 12- volt battery is 
used, battery performance may 
decrease and the EV system may 
not be able to restart.
• 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 EV system may not be able to 
start.
For details, consult your Toyota 
dealer.
WARNING
■When removing the 12-volt 
battery terminals
Always remove the negative (-) 
terminal first. If the positive (+) ter-
minal contacts any metal in the 
surrounding area when the posi-
tive (+) terminal is removed, a 
spark may occur, l eading to a fire 
in addition to electrical shocks 
and death or serious injury.
■Avoiding 12-volt battery fires 
or explosions
Observe the following precautions 
to prevent accidentally igniting the 
flammable gas that may be emit-
ted from the 12-volt battery:
●Make sure each jumper cable is 
connected to the correct termi-
nal and that it is not unintention-
ally in contact with any other 
than the intended terminal.
●Do not allow the other end of 
the jumper cable connected to 
the “+” terminal 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 lighter s or allow open 
flame near the 1 2-volt battery.
■12-volt battery precautions
The 12-volt battery contains poi-
sonous and corrosive acidic elec-
trolyte, while related parts contain 
lead and lead compounds. 
Observe the following precautions 
when handling the 12-volt battery:
●When working with the 12-volt 
battery, always wear safety 
glasses and take care not to 
allow any battery fluids (acid) to 
come into contact with skin, 
clothing or the vehicle body.
●Do not lean over the 12-volt bat-
tery.
●In the event that battery fluid 
(acid) comes into contact with 
the skin or eyes, immediately 
wash the affected area with 
water and seek medical atten-
tion.
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 and 
other battery-related parts.
●Do not allow children near the 
12-volt battery. 

5458-2. Steps to take in an emergency
Owners Manual_USA_M42C01_en
8
When trouble arises1 Stop the vehicle in a safe 
place and turn off the air con-
ditioning system.
2 Leave the EV system operat-
ing and carefully lift the hood.
3 Check if the cooling fan is 
operating. 
If the fan is operating: 
Wait until the “EV System 
overheated Output power 
reduced” message disap-
WARNING
■When replacing the 12-volt 
battery
●When the vent plug is close to 
the hold down cl amp, the bat-
tery fluid (acid) may leak.
●For information regarding bat-
tery replacement, contact your 
Toyota dealer.
NOTICE
■When handling jumper cables
When connecting the jumper 
cables, ensure that they do not 
become entangled in the cooling 
fan.
If  your vehicle over-
heats
When “EV System over-
heated Output power 
reduced” is shown on the 
multi-information display, 
your vehicle may be over-
heating.
NOTICE
■Cooling system coolant
The radiator coolant is exclusive 
for radiator usage. Damage may 
occur when water  or any other 
type of coolant is used, so never 
use any other fluid. When there is 
no “Toyota Genuine Traction Bat-
tery Coolant”, immediately contact 
your Toyota dealer.
Correction procedures