Get When trouble arises -> If the 12-volt battery is discharged Guide for Toyota bZ4X SUV Second Generation (2025-2026)

541

8-2. Steps to take in an emergency

cannot be started, contact your Toy-

If the 12-volt battery is

discharged

ota dealer.

■Stopping the EV system

Shift the shift position to P, set the

parking brake and press the power

switch as you normally do when

stopping the EV system.

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.

■Replacing the key battery

As the above procedure is a tempo-

rary measure, it is recommended

that the electronic key battery be

replaced immediately when the bat-

tery is depleted. (P.497)

Restarting the EV system

■Alarm

If a door is unlocked using the

mechanical key when the alarm sys-

tem is set, the alarm may be trig-

gered. (P.69)

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.

■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 changed each time

the switch is pressed. (P.234)

1 Confirm 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.70)

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-

Owners Manual_USA_M42C01_en

542

8-2. Steps to take in an emergency

tion.

4 Connect a positive jumper cable clamp to

on your vehicle and

connect the clamp on the other end of the positive cable to

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 terminal (second vehicle)

Solid, stationary, unpainted metallic point away from the battery

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.

Owners Manual_USA_M42C01_en

543

8-2. Steps to take in an emergency

■Charging the 12-volt battery

6 Open and close any of the

The electricity stored in the 12-volt

battery will discharge gradually even

when the vehicle is not in use, due

to natural discharge 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.)

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.

■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

9 Once the EV system has

started, remove the jumper

cables in the exact reverse

order from which they were

connected.

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 control or the

mechanical key to lock or unlock

the doors.

10Close the positive (+) battery

terminal cover.

●The EV 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.

Once the EV system starts,

have the vehicle inspected at

your Toyota dealer as soon as

possible.

●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.

■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.

●If the 12-volt battery discharges, it

may not be possible to shift the

shift position to other positions. In

this case, the vehicle cannot be

towed without lifting both front

wheels because the front wheels

will be locked.

●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.

●The power back door (if equipped)

Owners Manual_USA_M42C01_en

544

8-2. Steps to take in an emergency

must be initialized. (P.181)

●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.

■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 equivalent (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.

●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 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.

For details, consult your Toyota

dealer.

WARNING

●Do not lean over the 12-volt bat-

tery.

■When removing the 12-volt

battery terminals

●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 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, leading to a fire

in addition to electrical shocks

and death or serious injury.

■Avoiding 12-volt battery fires

or explosions

●Always wash your hands after

handling the 12-volt battery and

other battery-related parts.

Observe the following precautions

to prevent accidentally igniting the

flammable gas that may be emit-

ted from the 12-volt battery:

●Do not allow children near 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.

Owners Manual_USA_M42C01_en

When trouble arises -> If the 12-volt battery is discharged for Your Toyota bZ4X SUV Second Generation (2025-2026)

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