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4146-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■Chemicals in the 12-volt battery
The 12-volt battery contains poisonous and corrosive sulfuric acid and may produce
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 th ere 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 f eel 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 fol-
low the procedure above if necessary.
●If you accidentally swallow electrolyte
Drink a large quantity of water or milk. Get emergency medical attention immedi-
ately.
■When replacing the 12-volt battery
Use a 12-volt battery designed for this vehicle. Failure to do so may cause gas (hydro-
gen) to enter the passenger compartment, causing a fire or explosion.
For replacement of the 12-volt battery, contact any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer.
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415
6-3. Do-it-yourself maintenance
6
Maintenance and care
GS450h_300h_OM_OM30F92E_(EE)
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.
Page 435 of 600
435
6
6-3. Do-it-yourself maintenance
Maintenance and care
GS450h_300h_OM_OM30F92E_(EE)
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 battery cover.
To prevent damage to the key, cover the
tip of the screwdriver with a rag.
Replace the battery with a new one if it is depleted.
You will need th e following items:
Replacing the battery
1
2
3
Page 436 of 600

4366-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30F92E_(EE) Remove the depleted battery.
Insert a new battery with the “+” termi-
nal facing up.
■Use a CR2032 lithium battery
●Batteries can be purchased at any authorized Lexus retailer or Lexus authorized
repairer, or any reliable repairer, local el
ectrical 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.
■When the card key battery needs to be replaced (if equipped)
The battery for the card key is available only at Lexus dealers. Your Lexus dealer can
replace the battery for you.
■If the electronic key battery is depleted
The following symptoms may occur:
●The smart entry & start system and wireless remote control will not function properly.
●The operational range will be reduced.
4
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.
■Lithium battery precautions
CAUTION
RISK OF EXPLOSION IF BATTERY IS REPLACED BY AN INCORRECT TYPE.
DISPOSE OF USED BATTERIES ACCORDING TO THE INSTRUCTIONS
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.
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6-3. Do-it-yourself maintenance
6
Maintenance and care
GS450h_300h_OM_OM30F92E_(EE)
Trunk
Push the tab in and lift the lid off.
Remove the lid.
The upper part of the 12-volt battery
Pull the strap upwards to lift up the 12-
volt battery cover. When one or more of the fuses in this
unit are blown, the unit needs to be
replaced as a whole.
Remove the fuse with the pullout
tool.
Only type A fuse can be removed using
the pullout tool.
3
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451
7When trouble arises
GS450h_300h_OM_OM30F92E_(EE) 7-1. Essential information
Emergency flashers ..................452
If your vehicle has to be stopped in an
emergency.................................453 7-2. Steps to take in an
emergency
If your vehicle needs to be towed................................ 454
If you think something is wrong....................................... 459
If a warning light turns on or a warning buzzer
sounds..........................................460
If a warning message is displayed ................................ 466
If you have a flat tire (vehicles with spare tire) ......498
If you have a flat tire (vehicles without spare
tire)................................................509
If the hybrid system will not start................................ 523
If the parking brake cannot be released................. 525
If the electronic key does not operate properly ............. 527
If the 12-volt battery is discharged .................................530
If your vehicle overheats .........535
If the vehicle becomes stuck ............................................. 542
Page 452 of 600
4527-1. Essential information
GS450h_300h_OM_OM30F92E_(EE)
Emergency flashers
Press the switch. All the turn signal lights will flash.
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 operat-
ing (while the “READY” indicator is not illuminated), the 12-volt battery may discharge.
The emergency flashers are used to warn other drivers when the vehicle has
to be stopped in the road due to a breakdown, etc.
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463
7-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F92E_(EE) *
: Driver’s and front passenger’s seat belt buzzer:
The driver’s and front passenger’s seat belt buzzer sounds to alert the driver and front
passenger that his or her seat belt is not fastened. The buzzer sounds intermittently for
30 seconds after the vehicle reaches a speed of 20 km/h (12 mph). Then, if the seat
belt is still unfastened , the buzzer will sound in a different tone for 90 more seconds.
■Front passenger detection sensor, seat belt reminder and warning buzzer
●If luggage is placed on the front passenger seat, the front passenger detection sensor
may cause the warning light to flash and the warning buzzer to sound even if a passen-
ger is not sitting in the seat.
●If a cushion is placed on the seat, the sensor may not detect a passenger, and the warn-
ing light may not operate properly.
■If the malfunction indicator lamp comes on while driving
The malfunction indicator lamp will come on if the fuel tank becomes completely empty.
If the fuel tank is empty, refuel the vehicle immediately. The malfunction indicator lamp
will go off after several trips.
If the malfunction indicator la mp does not go off, contact any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer as soon as possible.
■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.
(If equipped)
Tire pressure warning light When the light comes on:
Low tire inflation pressure such as