Page 371 of 448
3717-2. Steps to take in an emergency
7
When trouble arises
cables and a second vehicle with a 12-
volt battery, you can jump start your 
vehicle using the following procedure.
1Confirm that the electronic key 
(including the card key) is being 
carried.
When connecting the jumper (or booster) 
cables, depending on the situation, the 
alarm may activate and doors locked. 
( P.73)
2 Open the hood ( P.302) and 
open the fuse box cover.
Push the tab in and lift the lid off.
LC500
LC500h
3 Open the exclusive jump starting 
terminal cover.
LC500
LC500h
4 Remove the engine cover. 
     
        
        Page 372 of 448
3727-2. Steps to take in an emergency
LC500LC500h
5 Connect a positive jumper cable 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 con-
nect the clamp at the other end of the negative cable to  .
LC500
A
B
C
D 
     
        
        Page 373 of 448

3737-2. Steps to take in an emergency
7
When trouble arises
LC500hExclusive jump starting terminal (your vehicle)
Positive (+) battery terminal (second vehicle)
Negative (-) battery terminal (second vehicle)
Solid, stationary, unpainted metallic point  away from the exclusive jump starting 
terminal and any mo ving parts as shown in the illustration
6 Start the engine of the second vehi-
cle. Increase the engine speed 
slightly and maintain at that level for 
approximately 5 minutes to 
recharge the 12-volt battery of your 
vehicle.
7 Open and close any of the door of 
your vehicle with the engine switch 
 off.
8 Maintain the engine speed of the 
second vehicle and start the engine 
 of your vehicle by 
turning the engine switch 
switch> to IGNITION ON mode 
.
9 Once the vehicle’s engine 
system> has started, remove the 
jumper cables in the exact reverse  order from which they were con-
nected.
10 Close the exclusive jump starting 
terminal cover, and reinstall the fuse 
box cover to its original position.
Once the engine  
starts, have the vehicle inspected at 
your Lexus dealer as soon as possible.
■Starting the engine  
when the 12-volt battery is discharged
The engine  cannot be 
started by push-starting.
■To prevent 12-volt battery discharge
●Turn off the headlights and the audio sys-
tem while the engine  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.
A
B
C
D 
     
        
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3757-2. Steps to take in an emergency
7
When trouble arises
Exhaust hole plug
Exhaust hole
Exhaust hose
For details, consult your Lexus dealer.
*1: LC500 for Canada or LC500 with  heated steering wheel
*2: LC500 except for Canada, LC500 without heated steering wheel or 
LC500h
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:
A
B
C
●Make sure each jumper cable is con-
nected to the correct terminal and that 
it is not unintentionally 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 meta l 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.
●If the 12-volt battery  fluid level is exces-
sively low ( P.313), do not use 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.
●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 ha nds after handling 
the 12-volt battery support, terminals, 
and other battery-related parts.
●Do not allow children near the 12-volt 
battery. 
     
        
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3767-2. Steps to take in an emergency
1Stop the vehicle in a safe place and 
turn off the air conditioning system, 
and then stop the engine.
2 If you see steam: 
Carefully lift the hood after the 
steam subsides.
If you do not see steam: 
Carefully lift the hood.
3 After the engine has cooled down 
sufficiently, inspect the hoses and 
WARNING
■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
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 vehi-
cle interior, and there is the possible dan-
ger 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 ve hicle in an emer-
gency. It cannot be used to jump start 
another vehicle.
If your vehicle overheats 
(LC500)
The following may indicate that 
your vehicle is overheating.
 The engine coolant temperature 
gauge ( P.82) is in the red zone 
or a loss of engine power is expe-
rienced. (For example, the vehicle 
speed does not increase.)
 “Engine Coolant Temp High” is 
shown on the multi-information 
display.
 Steam comes out from under the 
hood.
Correction procedures