Page 559 of 784

ES350_300h_OM_OM33B99U_(U)
5597-3. Do-it-yourself maintenance
7
Maintenance and care
■After recharging/reconnecting the 12-volt battery
The engine 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 engine.
●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 engine with the “START STOP ENGINE” switch in ACCESSORY mode.
The engine may not start with the “START STOP ENGINE” switch turned off. How-
ever, the engine will operate normally from the second attempt.
●The “START STOP ENGINE” switch mode is recorded by the vehicle. If the 12-volt
battery is reconnected, the vehicle will return the “START STOP ENGINE” switch
mode to the status it was in before the 12-volt battery was disconnected. Make sure
to turn off the engine before disconnect the 12-volt battery. Take extra care when
connecting the 12-volt battery if the “START STOP ENGINE” switch mode prior to
discharge is unknown.
If the engine will not start even after mu ltiple attempts, contact your Lexus dealer.
CAUTION
■Chemicals in the 12-volt battery
Batteries contain poisonous and corrosive sulfuric acid and may produce hydro-
gen 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.
1
2
3
Page 563 of 784

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
Page 584 of 784
584
ES350_300h_OM_OM33B99U_(U)
7-3. Do-it-yourself maintenance
Electronic key battery
●Flathead screwdriver
●Small flathead screwdriver
●Lithium battery CR2032
Take out the mechanical key.
Remove the cover.
To prevent damage to the key, cover
the tip of the screwdriver with a rag.
Remove the depleted battery.
Insert a new battery with the “+” termi-
nal facing up.
Replace the battery with a new one if it is depleted.
You will need the following items:
Replacing the battery
1
2
3
Page 585 of 784

ES350_300h_OM_OM33B99U_(U)
5857-3. Do-it-yourself maintenance
7
Maintenance and care
■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.
■If the electronic key battery is depleted
The following symptoms may occur:
●The smart access system with push-button start and wireless remote control will
not function properly.
●The operational range will be reduced.
CAUTION
■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
■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 component inside the remote control.
●Do not bend either of the battery terminals.
Page 613 of 784

613
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
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 )
Page 672 of 784

672
ES350_300h_OM_OM33B99U_(U)
8-2. Steps to take in an emergency
If the engine will not start (gasoline vehicles)
One of the following may be the cause of the problem:
●There may not be sufficient fuel in the vehicle’s tank.
Refuel the vehicle.
●The engine may be flooded.
Try to restart the engine again foll owing correct starting procedures.
( P. 205)
●There may be a malfunction in the engine immobilizer system.
( P. 8 4 )
One of the following may be the cause of the problem:
●The 12-volt battery may be discharged. ( P. 680)
●The 12-volt battery terminal connecti ons may be loose or corroded.
The engine starting system may be malfunctioning due to an electrical
problem such as electronic key ba ttery depletion or a blown fuse. How-
ever, an interim measure is available to start the engine. ( P. 673)
If the engine will not start even though correct starting procedures are
being followed ( P. 205), consider each of the following points:
The engine will not start even though the starter motor operates
normally.
The starter motor turns over slowly, the interior lights and head-
lights are dim, or the horn does not sound or sounds at a low vol-
ume.
The starter motor does not turn over
Page 674 of 784

674
ES350_300h_OM_OM33B99U_(U)
8-2. Steps to take in an emergency
If the hybrid system will not start (hybrid vehicles)
One of the following may be the cause of the problem:
●The electronic key may not be functioning properly. (P. 6 7 8 )
●There may not be sufficient fuel in the vehicle’s tank.
Refuel the vehicle.
●There may be a malfunction in the immobilizer system. ( P. 8 6 )
●There may be a malfunction in the steering lock system.
●The hybrid system may be malfunctio ning due to an electrical problem
such as electronic key battery de pletion or a blown fuse. However,
depending on the type of malfuncti on, an interim measure is available
to start the hybrid system. ( P. 675)
One of the following may be the cause of the problem:
●The 12-volt battery may be discharged. ( P. 6 8 4 )
●The 12-volt battery terminal connecti ons may be loose or corroded.
Reasons for the hybrid system not st arting vary depending on the situa-
tion. Check the following and perf orm the appropriate procedure:
The hybrid system will not start even though the correct starting
procedure is being followed. ( P. 2 1 2 )
The interior lights and headlights are dim, or the horn does not
sound or sounds at a low volume.