Page 378 of 602
376
GS350_300_GS F_OM_OM30G34U_(U)6-3. Do-it-yourself maintenance
Engine compartment
GS350
Fuse boxes (→
P. 412)
Battery ( →P. 390)
Engine oil level dipstick (→P. 381)
Engine coolant reservoir (→P. 386)
Engine oil filler cap ( →P. 383) Brake fluid reservoir
(→P. 389)
Washer fluid tank ( →P. 392)
Electric cooling fans
Condenser ( →P. 388)
Radiator (→ P. 388)1
2
3
4
5
6
7
8
9
10
Page 379 of 602
GS350_300_GS F_OM_OM30G34U_(U)
3776-3. Do-it-yourself maintenance
6
Maintenance and care
GS300
Fuse boxes (→P. 412)
Battery ( →P. 390)
Intercooler coolant reservoir (→P. 386)
Engine oil level dipstick (→P. 381)
Engine oil filler cap ( →P. 383) Engine coolant reservoir
(→P. 386)
Brake fluid reservoir (→P. 389)
Washer fluid tank ( →P. 392)
Condenser ( →P. 388)
Electric cooling fans
Radiator (→ P. 388)1
2
3
4
5
6
7
8
9
10
11
Page 380 of 602
378
GS350_300_GS F_OM_OM30G34U_(U)6-3. Do-it-yourself maintenance
GS F
Fuse boxes (→
P. 412)
Battery ( →P. 390)
Engine oil level dipstick (→P. 381)
Engine coolant reservoir (→P. 386)
Engine oil filler cap ( →P. 383) Brake fluid reservoir
(→P. 389)
Washer fluid tank ( →P. 392)
Electric cooling fans
Condenser ( →P. 388)
Radiator (→ P. 388)1
2
3
4
5
6
7
8
9
10
Page 392 of 602

390
GS350_300_GS F_OM_OM30G34U_(U)6-3. Do-it-yourself maintenance
Check the battery as follows.
■Battery exterior
Make sure that the 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 battery produces hydrogen gas which is flammable and explosive.
Therefore, observe the following before recharging:
●If recharging with the battery installed on the vehicle, be sure to disconnect the ground
cable.
●Make sure the power switch on the charge r is off when connecting and disconnecting
the charger cables to the battery.
■After recharging/reconnecting the 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 battery. If this happens, use the wireless
remote control or the mechanical key to lock/unlock the doors.
●Start the engine with the engine switch in ACCESSORY mode. The engine may not
start with the engine switch turned off. However, the engine will operate normally from
the second attempt.
●The engine switch mode is recorded by the vehicle. If the battery is reconnected, the
vehicle will return the engine switch mode to the status it was in before the battery was
disconnected. Make sure to turn off the engine before disconnect the battery. Take
extra care when connecting the battery if the engine switch mode prior to discharge is
unknown.
If the engine will not start even after multiple attempts at both methods, contact your
Lexus dealer.
Battery
1
2
1
2
3
Page 393 of 602

GS350_300_GS F_OM_OM30G34U_(U)
3916-3. Do-it-yourself maintenance
6
Maintenance and care
WARNING
■Chemicals in the battery
Batteries contain 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 wo rking on or near the battery:
●Do not cause sparks by touching the battery terminals with tools.
●Do not smoke or light a match near the battery.
●Avoid contact with eyes, skin and clothes.
●Never inhale or swallow electrolyte.
●Wear protective safety glasses when working near the battery.
●Keep children away from the battery.
■Where to safely charge the battery
Always charge the battery in an open area . Do not charge the battery in a garage or
closed room where there is insufficient ventilation.
■How to recharge the battery
Only perform a slow charge (5 A or less) . The battery may explode if charged at a
quicker rate.
■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 fe el pain or burning, get medical attention
immediately.
●If electrolyte gets on your clothes
It can soak through clothing on to your s kin. 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 emergenc y medical attention immedi-
ately.
NOTICE
■When recharging the battery
Never recharge the battery while the engine is running. Also, be sure all accessories
are turned off.
Page 412 of 602
410
GS350_300_GS F_OM_OM30G34U_(U)6-3. 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 413 of 602

GS350_300_GS F_OM_OM30G34U_(U)
4116-3. Do-it-yourself maintenance
6
Maintenance and care
■Use a CR2032 lithium battery
●Batteries can be purchased at your Lexus dealer, loca l 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.
■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 access system with push-button start and wireless remote control will not
function properly.
●The operational rang e will be reduced.
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 coul d 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 co mponent inside the remote control.
●Do not bend either of the battery terminals.
Page 425 of 602

423
GS350_300_GS F_OM_OM30G34U_(U)
7When trouble arises
7-1. Essential informationEmergency flashers................... 424
If your vehicle has to be stopped in an
emergency .................................425 7-2. Steps to take in an
emergency
If your vehicle needs to be towed................................ 426
If you think something is wrong ................ 432
Fuel pump shut off system ...... 433
If a warning light turns on or a warning buzzer
sounds.......................................... 434
If a warning message is displayed.......................................441
If you have a flat tire (vehicles with spare tire) ......................... 472
If you have a flat tire (vehicles without spare tire)...................483
If the engine will not start ........ 497
If the parking brake cannot be released ................................ 499
If the electronic key does not operate properly ...................... 501
If the vehicle battery is discharged .................................504
If your vehicle overheats .........509
If the vehicle becomes stuck .............................................. 515