battery Lexus ES300h 2020 Repair Manual

3276-3. Do-it-yourself maintenance
6
Maintenance and care
switch mode to the status it was in before
the 12-volt battery was disconnected.
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 hybrid system will not start even after
multiple attempts at all methods above,
contact your Lexus dealer.
Lift the luggage mat up.
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 insufficient ventilation.
■How to recharge the 12-volt battery
Recharge at a current of 5 A or less and
make sure that the recharging period
does not exceed a total of 12 hours.
■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.
Removing the 12-volt battery
cover

3286-3. Do-it-yourself maintenance
Make sure that the 12-volt battery ter-
minals are not corroded and that there
are no loose connections, cracks, or
loose clamps.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.
Exterior
Checking 12-volt battery condi-
tion
A
B
A
B
C

3436-3. Do-it-yourself maintenance
6
Maintenance and care
Remove the dust from the air intake
vent with a vacuum cleaner, etc.
Make sure to only use a vacuum to suck
out dust and clogs. Attempting to blow out
dust and clogs using an airgun, etc. may
push it into the air intake vent. ( P.345)
If dust and clogs cannot be completely
removed with the air intake vent cover
installed, remove the cover and clean the filter.
1
Turn the power switch off.
2 Using a Phillips screwdriver,
remove the clip.
3 Remove the air intake vent cover.
1 Pull the cover as shown in the illus-
tration to disengage the 7 claws,
starting from the claw in the upper
right corner.
2 Pull the cover toward the front of
the vehicle to remove it.
Cleaning the hybrid battery
(traction battery) air intake
vent and filter
To prevent the fuel economy from
being affected, visually inspect the
hybrid battery (traction battery) air
intake vent periodically for dust and
clogs. If it is dusty or clogged or if
“Maintenance Required for Trac-
tion Battery Cooling Parts See
Owner’s Manual” is displayed on
the multi-information display, clean
the air intake vent using the follow-
ing procedures:
Cleaning the air intake vent
If dust and clogs cannot be com-
pletely removed

3456-3. Do-it-yourself maintenance
6
Maintenance and care
8Using a Phillips screwdriver, install
the clip.
■Scheduled maintenance of the air
intake vent is necessary when
In some situations such as when the vehicle
is used frequently or in heavy traffic or dusty
areas, the air intake vent may need to be
cleaned more regularly.
For details, refer to “Owner’s Manual Sup-
plement” or “Scheduled Maintenance”.
■Cleaning the air intake vent
●Dust in the air intake vent may interfere
with the cooling of the hybrid battery
(traction battery). If charging/discharging
of the hybrid battery (traction battery)
becomes limited, the distance that the
vehicle can be driven using the electric
motor (traction motor) may be reduced
and the fuel economy may be reduced.
Inspect and clean the air intake vent peri-
odically.
●Improper handling of the air intake vent
cover and filter may result in damage to
them. If you have any concerns about
cleaning the filter, contact your Lexus
dealer.
■If “Maintenance required for Traction
battery cooling parts See owner’s man-
ual” is displayed on the multi-informa-
tion display
●If this warning message is displayed on
the multi-information display, remove the
air intake vent cover and clean the filter.
(  P.343)
●After cleaning the air intake vent, start
the hybrid system and check that the
warning message is no longer displayed.
After the hybrid system is started, it may be necessary to drive the vehicle up to
approximately 20 minutes before the
warning message disappears. If the warn-
ing message does not disappear after
driving for appropriately 20 minutes,
have the vehicle inspected by your Lexus
dealer.
WARNING
■When cleaning the air intake vent
●Do not use water or other liquids to
clean the air intake vent. If water is
applied to the hybrid battery (traction
battery) or other components, a mal-
function or fire may occur.
●Before cleaning the air intake vent,
make sure to turn the power switch off
to stop the hybrid system.
■When removing the air intake vent
cover
Do not touch the service plug located
near the air intake vent. ( P.64)
NOTICE
■When cleaning the air intake vent
When cleaning the air intake vent, make
sure to only use a vacuum to suck out
dust and clogs. If a compressed air blow
gun, etc. is used to blow out dust and
clogs, the dust or clogs may be pushed
into the air intake ve nt, which may affect
the performance of the hybrid battery
(traction battery) and cause a malfunc-
tion.

3466-3. Do-it-yourself maintenance
■If the electronic key battery is depleted
The following symptoms may occur:
●The smart access system with push-but-
ton start and wireless remote control will
not function properly.
●The operational range will be reduced.
Prepare the following before replacing
the battery:
 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
the local laws.
1Take out the mechanical key.
NOTICE
■To prevent damage to the vehicle
●Do not allow water or foreign matter to
enter the air intake vent when the
cover is removed.
●Carefully handle the removed filter so
that it will not be damage.
If the filter is damaged, have it replaced
with a new filter by your Lexus dealer.
●Make sure to reinstall the filter and
cover to their original positions after
cleaning.
●Do not install anything to the air intake
vent other than the exclusive filter for
this vehicle or use the vehicle without
the filter installed.
■If “Maintenance Required for Trac-
tion Battery Cooling Parts See
Owner’s Manual” is displayed on the
multi-information display
If the vehicle is continuously driven with
the warning message (indicating that
charging/discharging of the hybrid bat-
tery (traction battery) may become lim-
ited) displayed, the hybrid battery
(traction battery) may malfunction.
Electronic key battery
Replace the battery with a new one
if it is depleted.
Items to prepare
Replacing the battery

3476-3. Do-it-yourself maintenance
6
Maintenance and care
2Remove the cover.
To prevent damage to the key, wrap the tip
of the screwdriver with tape.
3Remove the depleted battery.
Insert a new battery with the “+” terminal
facing up.
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 screwdriver of appropriate 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.

355
7
7
When trouble arises
When trouble arises
7-1. Essential informationEmergency flashers.................. 356
If your vehicle has to be stopped in an emergency .......................... 356
If the vehicle is trapped in rising water............................................ 357
7-2. Steps to take in an emergency If your vehicle needs to be towed........................................................ 359
If you think something is wrong ........................................................ 362
If a warning light turns on or a warning buzzer sounds ....... 364
If a warning message is displayed ........................................................ 374
If you have a flat tire.................. 378
If the hybrid system will not start ........................................................ 385
If you lose your keys ................. 387
If the fuel filler door cannot be opened........................................ 387
If the electronic key does not operate properly .................... 388
If the 12-volt battery is discharged ........................................................ 390
If your vehicle overheats ........ 395
If the vehicle becomes stuck 398

3567-1. Essential information
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 the “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 dependin g 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.
2Shift the shift lever to N.
If the shift lever 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 lever 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 in 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

3717-2. Steps to take in an emergency
7
When trouble arises
■Brake hold operated indicator (warning buzzer)
■Hybrid system overheat warning light* (warning buzzer)
*: This light illuminates on the multi-information display.
■Master warning light (warning buzzer)
■Warning buzzer
In some cases, the bu zzer may not be heard
due to being in a noisy location or audio
sound.
■Front passenger detection sensor, seat
belt reminder and warning buzzer
●If luggage is placed on the front passen-
ger seat, the front passenger detection
sensor may cause th e warning light to
flash and the warning buzzer to sound
even if a passenger is not sitting in the
seat.
●If a cushion is placed on the seat, the sen-
sor may not detect a passenger, and the
warning light may not operate properly.
■SRS warning light
This warning light system monitors the air-
bag sensor assembly, fr ont impact sensors,
side impact sensors (front door), side
impact sensors (front), side impact sensors
(rear), driver’s seat position sensor, driver’s
seat belt buckle switch, front passenger
occupant classification system (ECU and
sensors), “AIR BAG ON” indicator light, “AIR BAG OFF” indicator light, front pas-
senger’s seat belt buckle switch, seat belt
pretensioners, airbags, interconnecting wir-
ing and power sources. (
P.28)
■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 warning
buzzer may sound.
■When the tire pressure warning light
comes on
Inspect the tires to check if a tire is punc-
tured.
If a tire is punctured:  P.378
If none of the tires are punctured:
Turn the power switch off then turn it to ON
mode. Check if the tire pressure warning
light comes on or blinks.
Warning lightDetails/Actions
(flashes)
Indicates a malfunction in the brake hold system
 Have the vehicle inspected by your Lexus dealer immediately.
Warning lightDetails/Actions
Indicates that the hybrid system has overheated
Stop the vehicle in a safe place. Handling method ( P.396)
Warning lightDetails/Actions
A buzzer sounds and the warning light comes on and flashes to indicate
that the master warning system has detected a malfunction.
 P.374

3757-2. Steps to take in an emergency
7
When trouble arises
*: A buzzer sounds the first time a message is shown on the multi-information display.
In some situations, the master warning light and warning buzzer may not oper-
ate as specified. In this case, follow the instructions displayed in the warning
message.
 If a warning light comes on or flashes at the same time that a warning message is
displayed, take corrective actio n according to the warning light. ( P.364)
■Warning messages
The warning messages explained below
may differ from the actual messages
according to operation conditions and vehi-
cle specifications.
■Warning buzzer
In some cases, the bu zzer may not be heard
due to being in a noisy location or audio
sound.
■If “Engine Oil Level Low Add or
Replace” is displayed
The engine oil level is low. Check the level
of the engine oil, and add if necessary.
This message may appear if the vehicle is
stopped on a slope. Move the vehicle to a
level surface and check to see if the mes-
sage disappears.
■If “Hybrid System Stopped Steering
Power Low” is displayed
This message is displayed if the hybrid sys- tem is stopped while driving.
When steering wheel operations are
heavier than usual, gr
ip the steering wheel
firmly and operate it using more force than
usual.
■If “Hybrid system overheated Output
power reduced” is displayed
This message may be displayed when driv-
ing under severe operat ing conditions. (For
example, when driving up a long steep hill.)
Handling method: P.395
■If “Traction Battery Needs to be Pro-
tected Refrain From the Use of N Posi-
tion” is displayed
This message may be displayed when the
shift lever is in N.
As the hybrid battery (traction battery) can
not be charged when the shift lever is in N,
shift the shift lever to P when the vehicle is
stopped.
Warning buzzer*Warning
Comes onSounds
Indicates an important situation, such as when a sys-
tem related to driving is ma lfunctioning or that dan-
ger may result if the co rrection procedure is not
performed
FlashesSoundsIndicates a situation, such as when damage to the
vehicle or danger may result
Comes onDoes not sound
Indicates a condition, such as malfunction of electri-
cal components, their condition, or indicates the
need for maintenance
FlashesDoes not sound
Indicates a situation, such as when an operation has
been performed incorrectly, or indicates how to
perform an operation correctly