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6-3. Do-it-yourself maintenance
■Before recharging
When recharging, the 12-volt battery produces 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 sys-
tem.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 mechanical 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 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 system will not start even after multiple attempts at all methods above, contact
your Lexus dealer.
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4416-3. Do-it-yourself maintenance
6
Maintenance and care
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 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.
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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 vehicle. 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 the hybrid system is operating. Also, be
sure all accessories are turned off.
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GS450h_OM_OM30F70U_(U)6-3. Do-it-yourself maintenance
6
Maintenance and care
Tires
Check if the treadwear indicators are showing on the tires. Also check the
tires for uneven wear, such as excessive wear on one side of the tread.
Check the spare tire condition and pressure if not rotated.
Replace or rotate tires in accord ance with maintenance schedules and
treadwear.
Checking tires
New tread
Worn tread
Treadwear indicator
The location of treadwear indicators is shown by the “TWI” or “ ∆” mark, etc.,
molded into the sidewall of each tire.
Replace the tires if the treadwear indicators are showing on a tire.
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6-3. Do-it-yourself maintenance
Rotate the tires in the order shown.
To equalize tire wear and extend tire
life, Lexus recommends that tire rota-
tion is carried out at the same interval
as tire inspection.
Do not fail to initialize the tire pressure
warning system after tire rotation.
XVehicles with front and rear tires of differing sizes
Tires cannot be rotated.
Tire rotation
Front
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4456-3. Do-it-yourself maintenance
6
Maintenance and care
Your vehicle is equipped with a tire pressure warning system that uses tire
pressure warning valves and transmitters to detect low tire inflation pres-
sure before serious problems arise.
XVehicles without the tire inflation pressure display function
If the tire pressure drops below a predetermined level, the driver is
warned by a warning light. ( →P. 507)
XVehicles with the tire inflation pressure display function
●If the tire pressure drops below a predetermined level, the driver is
warned by a screen display and a warning light. ( →P. 5 3 1 )
●The tire pressure detected by the tire pressure warning system can be
displayed on the multi-information display. ( →P. 99)
◆Installing tire pressure wa rning valves and transmitters
When replacing tires or wheels, tire pressure warning valves and trans-
mitters must also be installed.
When new tire pressure warning valves and transmitters are installed,
new ID codes must be registered in the tire pressure warning computer
and the tire pressure warning system must be initialized. Have tire pres-
sure warning valve and transmitter ID codes registered by your Lexus
dealer. ( →P. 4 4 7 )
◆Initializing the tire pressure warning system
■The tire pressure warning system must be initialized in the following
circumstances:
●When rotating the tires.
●When the tire inflation pressure is changed such as when changing
traveling speed or load weight.
When the tire pressure warning system is initialized, the current tire
inflation pressure is set as the benchmark pressure.
Tire pressure warning system
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6-3. Do-it-yourself maintenance
■How to initialize the tire pressure warning system
Park the vehicle in a safe place and turn the power switch off.
Initialization cannot be performed while the vehicle is moving.
Adjust the tire inflation pressure to the specified cold tire inflation
pressure level. ( →P. 582)
Make sure to adjust the tire pressure to the specified cold tire inflation pres-
sure level. The tire pressure warning system will operate based on this pressure
level.
Turn the power switch to ON mode.
Press and hold the tire pres-
sure warning reset switch until
the tire pressure warning light
blinks slowly 3 times.
Wait for a few minutes with the power switch in ON mode and then
turn the power switch off.
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4476-3. Do-it-yourself maintenance
6
Maintenance and care
◆Registering ID codes
The tire pressure warning valve and transmitter is equipped with a
unique ID code. When replacing a tire pressure warning valve and
transmitter, it is necessary to register the ID code. Have the ID code
registered by your Lexus dealer.
■When to replace your vehicle’s tires
Tires should be replaced if:
●The treadwear indicators are showing on a tire.
●You have tire damage such as cuts, splits, cracks deep enough to expose the fabric,
and bulges indicating internal damage
●A tire goes flat repeatedly or cannot be properly repaired due to the size or loca-
tion of a cut or other damage
If you are not sure, consult with your Lexus dealer.
■Replacing tires and wheels
If the ID code of the tire pressure warning valve and transmitter is not registered, the
tire pressure warning system will not work properly. After driving for about 20 min-
utes, the tire pressure warning light blinks for 1 minute and stays on to indicate a sys-
tem malfunction.
■Tire life
Any tire over 6 years old must be checked by a qualified technician even if it has sel-
dom or never been used or damage is not obvious.
■Routine tire inflation pressure checks
The tire pressure warning system does not replace routine tire inflation pressure
checks. Make sure to check tire inflation pressure as part of your routine of daily
vehicle checks.
■When rotating the tires (vehicles with the tire inflation pressure display function)
Make sure that the power switch is off. If the tires are rotated while the power switch
is in ON mode, the tire position information will not be updated.
If this accidentally occurs, either turn the power switch to off and then to ON mode,
or initialize the system after checking that the tire pressure is properly adjusted.
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