2021 LEXUS ES300h battery replacement

671-4. Hybrid system
1
For safety and security
There is an air intake vent under the
rear seat (right side) for the purpose of
cooling the hybrid battery (traction
battery). If the vent becomes blocked,
the hybrid battery (traction battery)
may overheat, leading to a reduction in
the hybrid battery (traction battery)
output.When a certain level of impact is
detected by the impact sensor, the
emergency shut off system blocks the
high voltage current and stops the fuel
pump to minimize the risk of electrocu-
tion and fuel leakage. If the emergency
shut off system activates, your vehicle
will not restart. To restart the hybrid
system, contact your Lexus dealer.
A message is automatically displayed
when a malfunction occurs in the
hybrid system or an improper opera-
tion is attempted.
If a warning message is shown on the
multi-information display, read the
NOTICE
■Hybrid battery (traction battery)
Do not carry large amounts of water
such as water cooler bottles in the vehi-
cle. If water spills onto the hybrid battery
(traction battery), the battery may be
damaged. Have the vehicle inspected by
your Lexus dealer.
Hybrid battery (traction battery)
air intake vent
NOTICE
■Hybrid battery (traction battery) air
intake vent
●Make sure not to block the air intake
vent with anything, such as a seat
cover, plastic cover, or luggage. If the
vents become blocked, the hybrid bat-
tery (traction battery) input and output
may be restricted, leading to a reduc-
tion in hybrid battery (traction battery)
output and a malfunction.
●When dust etc. has accumulated in the
air intake vent, periodically clean it
with a vacuum cleaner to prevent the
vent from clogging.
●A filter is installed to the air intake vent.
When the filter re mains noticeably
dirty even after cleaning the air intake
vent, filter cleaning or replacement is
recommended. When cleaning or
replacing the filter, contact your Lexus
dealer.
Refer to P.344 for details on how to
clean the filter.
●Do not get water or foreign materials
in the air intake vent as this may cause
a short circuit and damage the hybrid
battery (traction battery).
●Do not carry large amounts of water
such as water cooler bottles in the
vehicle. If water spills onto the hybrid
battery (traction battery), the battery
may be damaged. Have the vehicle
inspected by your Lexus dealer.
Emergency shut off system
Hybrid warning message

983-1. Key information
3-1.Key information
The following keys are provided with
the vehicle.
Electronic keys
• Operating the smart access system with push-button start ( P.112)
• Operating the wireless remote control function
Mechanical keys
Key number plate
■When riding in an aircraft
When bringing an elec tronic key onto an
aircraft, make sure you do not press any
buttons on the electronic key while inside
the aircraft cabin. If you are carrying an
electronic key in your bag etc., ensure that
the buttons are not likely to be pressed
accidentally. Pressing a button may cause
the electronic key to emit radio waves that
could interfere with the operation of the air-
craft.
■Electronic key battery depletion
●The standard battery life is 1 to 2 years.
●If the battery becomes low, an alarm will
sound in the cabin when the hybrid sys-
tem is stopped.
●Battery-saving mode can reduce the
power consumption of electronic keys
that are not used for long periods of time.
(  P.113)
●As the electronic key always receives
radio waves, the battery will become
depleted even if the electronic key is not
used. The following symptoms indicate
that the electronic key battery may be
depleted. Replace the battery when nec-
essary. ( P.347)
• The smart access system with push-but- ton start or the wireless remote control
does not operate.
• The detection area becomes smaller.
• The LED indicator on the key surface does not turn on.
You can replace the battery by yourself
(  P.347). However, as there is a danger
that the electronic key may be damaged, it
is recommended that replacement be car-
ried out by your Lexus dealer.
●To avoid serious dete rioration, do not
leave the electronic key within 3 ft. (1 m)
of the following electrical appliances that
produce a magnetic field:
•TVs
• Personal computers
• Cellular phones, cordless phones and battery chargers
• Recharging cellular phones or cordless
phones
•Table lamps
• Induction cookers
■Replacing the battery
 P.347
■Confirmation of the registered key
number
The number of keys already registered to
the vehicle can be confirmed. Ask your
Lexus dealer for details.
■If “A New Key has been Registered
Contact Your Dealer for Details” is
shown on the multi-information display
This message will be displayed each time
the driver’s door is opened when the doors
are unlocked from the outside for approxi-
mately 10 days after a new electronic key
has been registered.
If this message is disp layed but you have not
had a new electronic key registered, ask
your Lexus dealer to check if an unknown
electronic key (other than those in your
Keys
Key types
A
B
C

2544-6. Driving tips
Use fluids that are appropriate to
the prevailing outside temperatures.
•Engine oil
• Engine coolant/power control unit cool-
ant
•Washer fluid
 Have a service technician inspect
the condition of the 12-volt battery.
 Have the vehicle fitted with four
snow tires or purchase a set of tire
chains for the front tires.
*
Ensure that all tires are the specified size
and brand, and that chains match the size
of the tires.
*: Tire chains cannot be mounted on vehi-
cles with 18-inch tires.
Perform the following according to the
driving conditions:
 Do not try to forcibly open a window
Winter driving tips
Carry out the necessary prepara-
tions and inspections before driving
the vehicle in winter. Always drive
the vehicle in a manner appropriate
to the prevailing weather condi-
tions.
Preparation for winter
WARNING
■Driving with snow tires
Observe the following precautions to
reduce the risk of accidents.
Failure to do so may result in a loss of
vehicle control and cause death or seri-
ous injury.
●Use tires of the specified size.
●Maintain the recommended level of air
pressure.
●Do not drive in excess of 75 mph (120
km/h), regardless of the type of snow
tires being used.
●Use snow tires on all, not just some
wheels.
■Driving with tire chains (vehicles with
17-inch tires)
Observe the following precautions to
reduce the risk of accidents.
Failure to do so may result in the vehicle
being unable to be driven safely, and may
cause death or serious injury.
●Do not drive in excess of the speed
limit specified for the tire chains being
used, or 30 mph (50 km/h), which-
ever is lower.
●Avoid driving on bumpy road surfaces
or over potholes.
●Avoid sudden acceleration, abrupt
steering, sudden br aking and shifting
operations that cause sudden engine
braking.
●Slow down sufficiently before entering
a curve to ensure that vehicle control
is maintained.
●Do not use LTA (Lane Tracing Assist)
system.
NOTICE
■Repairing or replacing snow tires
Request repairs or replacement of snow
tires from Lexus dealers or legitimate tire
retailers.
This is because the removal and attach-
ment of snow tires affects the operation
of the tire pressure warning valves and
transmitters.
Before driving the vehicle

3126-2. Maintenance
6-2.Maintenance
■Repair and replacement
It is recommended that genuine Lexus parts
be used for repairs to ensure performance
of each system. If non-Lexus parts are used
in replacement or if a repair shop other than
a Lexus dealer perfor ms repairs, confirm
the warranty coverage.
■Allow inspection and repairs to be per-
formed by a Lexus dealer
●Lexus technicians are well-trained spe-
cialists and are kept up to date with the
latest service information. They are well
informed about the operations of all sys-
tems on your vehicle.
●Keep a copy of the repa ir order. It proves
that the maintenance that has been per-
formed is under warranty coverage. If
any problem should arise while your vehi-
cle is under warranty, your Lexus dealer
will promptly take care of it.
General maintenance should be per-
formed on a daily basis. This can be
done by yourself or by a Lexus dealer.
Scheduled maintenance should be
performed at specified intervals
according to the maintenance sched-
ule.
For details about ma intenance items and
schedules, refer to the “Warranty and Ser-
vice Guide”, “Owner’s Manual Supple-
ment” or “Scheduled Maintenance”.
■Resetting the message indicating main-
tenance is required
After the required maintenance is per-
formed according to the maintenance
schedule, please reset the message.
To reset the message, follow the procedure
described below:
1 Press or of the meter control
switches and select .
2 Press or of the meter control
switches and select “Vehicle Settings”.
Then press “OK”.
Maintenance requirements
To ensure safe and economical
driving, day-to-day care and regu-
lar maintenance are essential. It is
the owner’s responsibility to per-
form regular checks. Lexus recom-
mends the following maintenance:
WARNING
■If your vehicle is not properly main-
tained
Improper maintenanc e could result in
serious damage to the vehicle and possi-
ble death or serious injury.
■Handling of the 12-volt battery
●Engine exhaust, some of its constitu-
ents, and a wide variety of automobile
components contain or emit chemicals
known to the State of California to
cause cancer and birth defects and
other reproductive harm. Work in a
well ventilated area.
●Oils, fuels and fluids contained in vehi-
cles as well as waste produced by
component wear contain or emit
chemicals known to the State of Cali-
fornia to cause cancer and birth
defects or other re productive harm.
Avoid exposure and wash any affected
area immediately.
●12-volt battery post s, terminals and
related accessories contain lead and
lead compounds which are known to
cause brain damage. Wash your hands
after handling. ( P.326)
General maintenance
Scheduled maintenance

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
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
battery 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

4068-1. Specifications
■Spark plug
*: The fluid capacity is a reference quantity.If replacement is necessary, contact your Lexus dealer.
Ignition system
MakeDENSO FC16HR-Q8
Gap0.031 in. (0.8 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.
Electrical system (12-volt battery)
Open voltage at 68°F (20°C):12.0 V or higher
(Turn the power switch off and turn on the high beam
headlights for 30 seconds.)
Charging rates
Quick charge
Slow charge
15 A max.
5 A max.
Hybrid transmission
Fluid capacity*4.1 qt. (3.9 L, 3.4 Imp.qt.)
Fluid typeToyota Genuine ATF WS
NOTICE
■Hybrid transmission fluid type
Using transmission fluid other than the above type may cause abnormal noise or vibra-
tion, or ultimately damage the transmission of your vehicle.
Brakes
Pedal clearance*13.3 in. (85 mm) Min.
Pedal free play0.04  0.24 in. (1.0  6.0 mm)
Brake pad wear limit0.04 in. (1.0 mm)