2018 LEXUS LS500H battery

3936-3. Do-it-yourself maintenance
LS500h_OM_OM50F42U_(U) 6
Maintenance and care The 12-volt battery is located in the
trunk under the luggage mat.
Removing the luggage mat: → P.348
■
Before recharging
When recharging, the 12-volt battery pro-
duces hydrogen gas which is flammable
and explosive. Therefore, observe the fol-
lowing precautions before recharging: ●
If recharging with the 12-volt battery
installed on the vehicle, be sure to discon-
nect the ground cable. ●
Make sure the power switch on the char-
ger is off when connecting and discon-
necting the charger cables to the 12-volt
battery. ■
After recharging/reconnecting the
12-volt battery ●
Unlocking the doors using the smart
access system with push-button may not
be possible immediately after reconnect-
ing the 12-volt battery. If this happens, use
the wireless remote control or the
mechanical key to lo ck/unlock the doors.
●
Start the hybrid system with the power
switch in ACCESSORY mode. The
hybrid system may not start with the
power switch turned off. However, the
hybrid system will operate normally from
the second attempt.
●
The power switch mode is recorded by
the vehicle. If the 12-volt battery is recon-NOTICE■
Diluting washer fluid
Dilute washer fluid with water as neces-
sary.
Refer to the freezing temperatures listed
on the label of the washer fluid bottle.
12-volt battery
Location

394 6-3. Do-it-yourself maintenance
LS500h_OM_OM50F42U_(U) nected, the vehicle will return the power
switch mode to the status it was in before
the 12-volt battery was disconnected.
Make sure to turn off the power before
disconnecting the 12-volt battery. Take
extra care when connecting the 12-volt
battery if the power sw itch mode prior to
discharge is unknown.
If the system will not st art even after multiple
attempts, contact your Lexus dealer.
Make sure that the 12-volt battery ter-
minals are not corroded and that there
are no loose connections, cracks, or
loose clamps.WARNING■
Chemicals in the 12-volt battery
The 12-volt battery contains poisonous
and corrosive sulfuric acid and may pro-
duce hydrogen gas which is flammable
and explosive. To reduce the risk of death
or serious injury, take the following pre-
cautions while working on or near the
12-volt battery: ●
Do not cause sparks by touching the
12-volt battery terminals with tools.●
Do not smoke or light a match near the
12-volt battery.●
Avoid contact with eyes, skin and
clothes.●
Never inhale or swallow electrolyte.
●
Wear protective safety glasses when
working near the 12-volt battery.
●
Keep children away from the 12-volt
battery.
■
Where to safely charge the 12-volt
battery
Always charge the 12-volt battery in an
open area. Do not charge the 12-volt bat-
tery in a garage or closed room where
there is insuffic ient ventilation. ■
Emergency measures regarding
electrolyte ●
If electrolyte gets in your eyes
Flush your eyes with clean water for at
least 15 minutes and get immediate
medical attention. If possible, continue
to apply water with a sponge or cloth
while traveling to the nearest medical
facility. ●
If electrolyte gets on your skin
Wash the affected area thoroughly. If
you feel pain or burning, get medical
attention immediately. ●
If electrolyte gets on your clothes
It can soak through clothing on to your
skin. Immediately take off the clothing
and follow the procedure above if nec-
essary. ●
If you accidentally swallow electrolyte
Drink a large quantity of water or milk.
Get emergency medical attention
immediately. ■
When replacing the 12-volt battery
Use a 12-volt battery designed for this
vehicle. Failure to do so may cause gas
(hydrogen) to enter the passenger com-
partment, causing a fire or explosion.
For replacement of the 12-volt battery,
contact your Lexus dealer.
NOTICE
■
When recharging the 12-volt battery
Never recharge the 12-volt battery while
the hybrid system is operating. Also, be
sure all accessories are turned off.
Exterior

3956-3. Do-it-yourself maintenance
LS500h_OM_OM50F42U_(U) 6
Maintenance and care Terminals
Hold-down clamp
Check the 12-volt battery condition by
indicator color.
Blue: Good condition
Red: Charging is necessary.
Have the vehicle inspected by your
Lexus dealer.
Clear: Replacement is necessary.
Have the 12-volt battery checked
by your Lexus dealer. Check if the treadw ear indicators are
showing on the tires. Also check the
tires for uneven wear, such as excessive
wear on one side of the tread.
New tread
Worn tread
Treadwear indicator The location of treadwear indicators is
shown by a “TWI” or “ ” mark, etc.,
molded into the sidewall of each tire.
Replace the tires if the treadwear indica-
tors are showing on a tire.Checking the 12-volt battery
condition A
B
A
B
C Tires Replace or rotate tires in accor-
dance with maintenance schedules
and treadwear.
Checking tires
A
B
C

4136-3. Do-it-yourself maintenance
LS500h_OM_OM50F42U_(U) 6
Maintenance and care ■
If the electronic key battery is depleted
The following symptoms may occur: ●
The smart access syst em with push-but-
ton start and wireless remote control will
not function properly.●
The operational rang e will be reduced.■
When the card key battery needs to be
replaced (if equipped)
The battery for th e card key is available only
at Lexus dealers. Your Lexus dealer can
replace the battery for you.
 Flathead screwdriver
 Small flathead screwdriver
 Lithium battery CR2032 ■
Use a CR2032 lithium battery●
Batteries can be purchased at your Lexus
dealer, local electrical appliance shops or
camera stores.
●
Replace only with the same or equivalent
type recommended by the manufacturer.
●
Dispose of used batteries according to
local laws. 1 Take out the mechanical key.
2 Remove the cover. To prevent damage to the key, cover the tip
of the flathead scre wdriver with a tape.
3 Remove the depleted battery. Insert a new battery with the “+” terminal
facing up.Electronic key battery Replace the battery with a new one
if it is depleted.
As the key may be damaged if the
following procedure is not per-
formed properly, it is recom-
mended that key battery
replacement be performed by your
Lexus dealer.
Items to prepare Replacing the battery

414 6-3. Do-it-yourself maintenance
LS500h_OM_OM50F42U_(U) 1 Turn the power switch off.
2 Open the fuse box cover. 
Engine compartment: type A fuse
box Push the tabs in and lift the lid off.

Engine compartment: type B fuse
box Remove the engine compartment cover
( → P.388) and push the ta bs in and lift the
lid off.WARNING■
Removed battery and other parts
These parts are small and if swallowed by
a child, they can cause choking. Keep
away from children. Failure to do so
could result in death or serious injury.
NOTICE■
When replacing the battery
Use a flathead screwdriver of appropri-
ate size. Applying excessive force may
deform or damage the cover. ■
For normal operation after replacing
the battery
Observe the following precautions to
prevent accidents: ●
Always work with dry hands.
Moisture may cause the battery to
rust.●
Do not touch or move any other com-
ponent inside the remote control.●
Do not bend either of the battery ter-
minals. Checking and replacing
fuses If any of the electrical components
do not operate, a fuse may have
blown. If this happens, check and
replace the fuses as necessary.
Checking and replacing fuses

419
LS500h_OM_OM50F42U_(U) 7 7
When trouble arises When trouble arises .
7-1. Essential information
Emergency flashers.................. 420
If your vehicle has to be stopped in
an emergency .......................... 420
7-2. Steps to take in an emergency
If your vehicle needs to be towed
........................................................ 422
If you think something is wrong
........................................................ 426
If a warning light turns on or a
warning buzzer sounds ....... 427
If a warning message is displayed
........................................................ 437
If you have a flat tire.................. 442
If the hybrid system will not start
........................................................ 443
If you lose your keys ................. 444
If the fuel filler door cannot be
opened........................................ 445
If the electronic key does not
operate properly .................... 445
If the 12-volt battery is discharged
........................................................ 447
If your vehicle overheats ........ 453
If the vehicle becomes stuck
........................................................ 457

420 7-1. Essential information
LS500h_OM_OM50F42U_(U) 7-1.Essential information
Press the switch to flash all of the turn
signal lights. To turn them off, press the switch once
again.
■
Emergency flashers●
If the emergency flashers are used for a
long time while the hybrid system is not
operating (while th e “READY” indicator
is not illuminated), the 12-volt battery may
discharge.●
If any of the SRS airbags deploy (inflate)
or in the event of a strong rear impact, the
emergency flashers will turn on automati-
cally.
The emergency flashers will turn off auto-
matically after operating for approxi-
mately 20 minutes. To manually turn the
emergency flashers off, press the switch
twice.
(The emergency flashers may not turn on
automatically depending on the force of
the impact and conditions of the colli-
sion.) 1 Steadily step on the brake pedal
with both feet and firmly depress it. Do not pump the brake pedal repeatedly
as this will increase the effort required to
slow the vehicle.
2 Shift the shift position to N. 
If the shift position is shifted to N
3 After slowing down, stop the vehi-
cle in a safe place by the road.
4 Stop the hybrid system. 
If the shift position cannot be shifted
to N
3 Keep depressing the brake pedal
with both feet to reduce vehicle
speed as much as possible.
4 To stop the hybrid system, press
and hold the power switch for 2
consecutive seconds or more, or Emergency flashers The emergency flashers are used to
warn other drivers when the vehicle
has to be stopped on the road due
to a breakdown, etc.
Operating instructions If your vehicle has to be
stopped in an emergency Only in an emergency, such as if it
becomes impossible to stop the
vehicle in the normal way, stop the
vehicle using the following proce-
dure:
Stopping the vehicle

4237-2. Steps to take in an emergency
LS500h_OM_OM50F42U_(U) 7
When trouble arises
In the following situations, it is not pos-
sible to be towed by another vehicle
using cables or chains, as the rear
wheels may be locked due to the park-
ing lock. Contact your Lexus dealer or
commercial towing service.
 There is a malfunction in the shift control system. ( → P.171, 437)
 There is a malfunction in the immo-
bilizer system. ( → P.66)
 There is a malfunction in the smart
access system with push-button
start. ( → P.445)
 The 12-volt battery is discharged.
( → P.447)
The following may indicate a problem
with your transmission. Contact your
Lexus dealer or commercial towing
service before towing.
 The hybrid system warning message
is shown on the multi-information
display and the vehicle does not
move.
 The vehicle makes an abnormal
sound.
Do not tow with a sling-type truck to
prevent body damage.WARNING■
Installing towing eyelets to the vehi-
cle
Make sure that towing eyelets are
installed securely.
If not securely installed, towing eyelets
may come loose during towing.
NOTICE■
To prevent damage to the vehicle
when towing using a wheel-lift type
truck●
Do not tow the vehicle from the rear
when the power switch is off. The
steering lock mechanism is not strong
enough to hold the front wheels
straight.●
When raising the vehicle, ensure ade-
quate ground clearance for towing at
the opposite end of the raised vehicle.
Without adequate clearance, the vehi-
cle could be damaged while being
towed.■
To prevent damage to the vehicle
when towing with a sling-type truck
Do not tow with a sling-type truck, either
from the front or rear.
■
To prevent damage to the vehicle
during emergency towing
Do not secure cables or chains to the
suspension components.
Situations when it is not possible
to be towed by another vehicle Situations when it is necessary to
contact dealers before towing
Towing with a sling-type truck