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ES350_300h_OM_OM33B99U_(U)
7-3. Do-it-yourself maintenance
12-volt battery (hybrid vehicles)
The 12-volt battery is located on the
right-hand side of luggage com-
partment.
Remove the 12-volt battery cover.Install the cover
Lift the tab to se cure to the trunk
liner
Location
Removing the 12-volt battery cover
Installing the 12-volt battery cover
1
2
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ES350_300h_OM_OM33B99U_(U)
5637-3. Do-it-yourself maintenance
7
Maintenance and care
Make sure that the 12-volt battery terminals are not corroded and that
there are no loose connections, cracks, or loose clamps.
Terminals
Hold-down clamp
■Before recharging
When recharging, the 12-volt battery prod uces hydrogen gas which is flammable
and explosive. Therefore, observe the following precautions before recharging:
●If recharging with the 12-volt battery installed on the vehicle, be sure to disconnect
the ground cable.
●Make sure the power switch on the charger is off when connecting and discon-
necting the charger cables to the 12-volt battery.
■After recharging/reconnecting the 12-volt battery
●The hybrid system may not start. Follow the procedure below to initialize the system.
Shift the shift lever to P.
Open and close any of the doors.
Restart the hybrid system.
●Unlocking the doors using the smart access system with push-button start may not
be possible immediately after reconnecting the 12-volt battery. If this happens, use
the wireless remote control or the me chanical key to lock/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-
nected, the vehicle will return the “POWER” switch mode to the status it was in
before the 12-volt battery was disconnect ed. Make sure to turn off the “POWER”
switch before disconnect the 12-volt battery. Take extra care when connecting the 12-
volt battery if the “POWER” switch mode prior to discharge is unknown.
If the system will not start even after mult iple attempts at all methods above, contact
your Lexus dealer.
Exterior
1
2
1
2
3
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ES350_300h_OM_OM33B99U_(U)
7-3. Do-it-yourself maintenance
CAUTION
■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 precautions 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 wh ere there is insufficient ventilation.
■How to recharge the 12-volt battery
Only perform a slow charge (5 A or less). The 12-volt battery may explode if
charged at a quicker rate.
Page 565 of 784

ES350_300h_OM_OM33B99U_(U)
5657-3. Do-it-yourself maintenance
7
Maintenance and care
CAUTION
■Emergency measures regarding electrolyte
●If electrolyte gets in your eyes
Flush your eyes with clean water for at least 15 minutes and get immediate medi-
cal 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 atten-
tion 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 necessary.
●If you accidentally swallow electrolyte
Drink a large quantity of water or milk . Get emergency medical attention imme-
diately.
■When replacing the 12-volt battery
Use a 12-volt battery designed for this ve hicle. Failure to do so may cause gas
(hydrogen) to enter the passenger compartment, 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 th e hybrid system is operating. Also, be
sure all accessories are turned off.
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ES350_300h_OM_OM33B99U_(U)
8When trouble arises
8-1. Essential informationEmergency flashers.................... 614
If your vehicle has to be stopped in an emergency ..... 615 8-2. Steps to take in an emergency
If your vehicle needs to be towed .................................. 617
If you think something is wrong ................ 624
Fuel pump shut off system (gasoline vehicles) .................. 625
If a warning light turns on or a warning buzzer sounds ..... 626
If a warning message is displayed ................................ 636
If you have a flat tire................... 659
If the engine will not start (gasoline vehicles) ...................672
If the hybrid system will not start (hybrid vehicles) ............. 674
If the shift lever cannot be shifted from P ...................... 676
If the electronic key does not operate properly ......................677
If the 12-volt battery is discharged (gasoline
vehicles) ..................................... 680
If the 12-volt battery is discharged (hybrid
vehicles) ......................................684
If your vehicle overheats (gasoline vehicles) ................. 688
If your vehicle overheats (hybrid vehicles) ....................... 691
If the vehicle becomes stuck ..............................................697
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614
ES350_300h_OM_OM33B99U_(U)
8-1. Essential information
Emergency flashers
Press the switch.
All the turn signal lights will flash.
To turn them off, press the switch once again.
■Emergency flashers
Gasoline vehicles: If the emergency flashers are used for a long time while the
engine is not operating, the 12-volt battery may discharge.
Hybrid vehicles: If the emergency flashers are used for a long time while the hybrid
system is not operating (while the “READY” indicator is not illuminated), the 12-volt
battery may discharge.
The emergency flashers are used to warn other drivers when the vehi-
cle has to be stopped in the road due to a breakdown, etc.
Ty p e AType B
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6328-2. Steps to take in an emergency
ES350_300h_OM_OM33B99U_(U)
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such as natural
air leaks and tire inflation pressure changes caused by temperature. In this case,
adjusting the tire inflation pressure will turn off the warning light (after a few minutes).
■When a tire is replaced with a spare tire
Vehicles with a compact spare tire: The compact spare tire is not equipped with a tire
pressure warning valve and transmitter. If a tire goes flat, the tire pressure warning
light will not turn off even though the flat tire has been replaced with the spare tire.
Vehicles with a full-size spare tire: The spare tire is also equipped with a tire pressure
warning valve and transmitter. The tire pressure warning light will turn on if the tire
inflation pressure of the spare tire is low. If a tire goes flat, the tire pressure warning
light will not turn off even though the flat tire has been replaced with the spare tire.
■Conditions that the tire pressure warning system may not function properly
P. 5 7 1
■If the tire pressure warning light freque ntly comes on after blinking for 1 minute
If the tire pressure warning light frequently comes on after blinking for 1 minute when
the “START STOP ENGINE” <“POWER”> switch is turned to IGNITION ON
mode, have it checked by your Lexus dealer.
■Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insufficient or the voltage temporarily
drops, the electric power steering system warning light may come on and the warn-
ing buzzer may sound.
■Warning buzzer
In some cases, the buzzer may not be he ard because of noisy place or an audio
sound.
Page 656 of 784
6568-2. Steps to take in an emergency
ES350_300h_OM_OM33B99U_(U)
InteriorbuzzerExterior
buzzerWa r n i n g m e s s a g eDetailsCorrection procedure
Power was turned
off due to the auto-
matic power off
function.
Next time
when start-
ing the
engine
tem>,
increase the
engine
speed
slightly and
maintain
that level for
approxi-
mately 5
minutes to
recharge
the 12-volt
battery.
OnceThe electronic key
has a low battery.
Replace the
electronic
key batter y.
( P. 5 8 4 )