Page 668 of 910

ES350 300h_OM_OM33A01U_(U)
6676-3. Do-it-yourself maintenance
6
Maintenance and care
CAUTION
The engine compartment contains many mechanisms and fluids that may move sud-
denly, become hot, or become electrically energized. To avoid death or serious
injury, observe the following precautions.
■When working on the engine compartment
●Hybrid vehicles: Make sure that the “POWER ON” on the multi-information dis-
play and the “READY” indicator are both off.
●Keep hands, clothing and tools away from the moving fan and engine drive belt.
●Gasoline vehicles: Be careful not to touch the engine, radiator, exhaust manifold,
etc. right after driving as they may be hot. Oil and other fluids may also be hot.
●Hybrid vehicles: Be careful not to touch the engine, power control unit, radiator,
exhaust manifold, etc. right after driving as they may be hot. Oil and other fluids
may also be hot.
●Do not leave anything that may burn easily, such as paper and rags, in the engine
compartment.
●Gasoline vehicles: Do not smoke, cause sparks or expose an open flame to fuel
or the 12-volt battery. Fuel and 12-volt battery fumes are flammable.
●Hybrid vehicles: Do not smoke, cause sparks or expose an open flame to fuel.
Fuel fumes are flammable.
●Gasoline vehicles: Be extremely cautious when working on the 12-volt battery. It
contains poisonous and corrosive sulfuric acid.
Page 684 of 910
ES350 300h_OM_OM33A01U_(U)
6836-3. Do-it-yourself maintenance
6
Maintenance and care
Check the radiator and condenser and clear away any foreign objects.
If either of the above parts is extremely dirty or you are not sure of their
condition, have your vehicle inspected by your Lexus dealer.
Radiator and condenser
CAUTION
■When the engine is hot
Do not touch the radiator or condenser as they may be hot and cause serious inju-
ries, such as burns.
Page 688 of 910

ES350 300h_OM_OM33A01U_(U)
6876-3. Do-it-yourself maintenance
6
Maintenance and care
■After recharging/reconnecting the 12-volt 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 12-volt battery. If this happens, use
the wireless remote control or the mechanical key to lock/unlock the doors.
●Start the engine with the “START STOP ENGINE” switch in ACCESSORY mode.
The engine may not start with the “START STOP ENGINE” switch turned off. How-
ever, the engine will operate normally from the second attempt.
●The “START STOP ENGINE” switch mode is recorded by the vehicle. If the 12-volt
battery is reconnected, the vehicle will return the “START STOP ENGINE” switch
mode to the status it was in before the 12-volt battery was disconnected. Make sure
to turn off the engine before disconnect the 12-volt battery. Take extra care when
connecting the 12-volt battery if the “START STOP ENGINE” switch mode prior to
discharge is unknown.
If the engine will not start even after multiple attempts, contact your Lexus dealer.
CAUTION
■Chemicals in the 12-volt battery
Batteries contain poisonous and corrosive sulfuric acid and may produce hydro-
gen 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.
1
2
3
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692
ES350 300h_OM_OM33A01U_(U)
6-3. Do-it-yourself maintenance
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
Only perform a slow charge (5 A or less). The 12-volt battery may explode if
charged at a quicker rate.
Page 712 of 910

ES350 300h_OM_OM33A01U_(U)
7116-3. Do-it-yourself maintenance
6
Maintenance and care
■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 local laws.
■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 range will be reduced.
CAUTION
■Removed battery and other parts
Keep away from children. These parts are small and if swallowed by a child, they
can cause choking. Failure to do so could 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 component inside the remote control.
●Do not bend either of the battery terminals.
Page 717 of 910
716
ES350 300h_OM_OM33A01U_(U)
6-3. Do-it-yourself maintenance
FuseAmpereCircuit
1WIP-S5Driver support system, windshield wipers
2FA N50Electric cooling fan
3H-LP CLN30No circuit
4ENG W/PMP*130Cooling system
5PTC HTR NO.250PTC heater
6PTC HTR NO.150PTC heater
7HTR50Air conditioning system
8ALT*2140Charging system
DC/DC*1120Hybrid system
9ABS NO.2*230VSC, ABS
10ST/AM2*230Starting system
ABS NO.1*130VSC, ABS
11H-LP-MAIN30H-LP RH-LO, H-LP LH-LO
12ABS MTR NO.2*150VSC, ABS
13ABS NO.1*250VSC, ABS
ABS MTR NO.1*150VSC, ABS
14R/B NO.2*150IGCT MAIN, INV W/PMP
15EPS80Electric power steering
16S-HORN7. 5S-HORN
17DEICER15Windshield deicer
18HORN10Horn
19TV15
Multi-information display, audio display,
Remote Touch, audio system, gauges and
meters
20AMP NO.230Audio system
21EFI NO.215
Multiport fuel injection system, sequential
multiport fuel system, electronic controlled
transmission
Page 719 of 910
718
ES350 300h_OM_OM33A01U_(U)
6-3. Do-it-yourself maintenance
*1:Hybrid vehicles
*2: Gasoline vehicles
40
A/F*220Air intake system
EFI-MAIN
NO.2
*120Fuel system, air intake system, exhaust sys-
tem
41AM27. 5Power management system, smart access
system with push-button start
42PA N E L10
Switch illumination, audio system, multi-infor-
mation display, audio display, shift lever light,
glove box light, console box light, Remote
Touch, intuitive parking assist switch illumina-
tion
43DOME7. 5Clock, footwell lights, vanity lights, ornament
lights, personal lights, door courtesy lights
44ECU-B NO.110
Smart access system with push-button start,
main body ECU, steering sensor, gauges and
meters, gateway ECU, electric tilt and tele-
scopic steering column, power seats, over-
head module, outside mirror control ECU,
power trunk opener and closer ECU
45SPARE25Spare fuse
46SPARE30Spare fuse
FuseAmpereCircuit
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ES350 300h_OM_OM33A01U_(U)
7216-3. Do-it-yourself maintenance
6
Maintenance and care
12WIPER25Windshield wipers
13BKUP LP7. 5
Multiport fuel injection system, sequential
multiport fuel system, electronic controlled
transmission, audio system, navigation sys-
tem, back-up lights
14FUEL OPN10Fuel filler door opener
15EPS-IG110Electric power steering
16P/O U T L E T R R15Po w e r o u t l e t
17RADIO-ACC5Audio system, Remote Touch, multi-informa-
tion display, audio display, navigation system
18S / H T R & FA N F/ R10Seat heaters and ventilators
19S / H T R & FA N F/ L10Seat heaters and ventilators
20OBD7. 5On-Board diagnosis system
21ECU-B NO.210
Power window master switch, air condition-
ing system, smart access system with push-
button start, tire pressure warning system,
rear sunshade
22STRG HTR10Heated steering wheel
23PTL25Power trunk opener and closer ECU
24STOP7. 5
Power management system, multiport fuel
injection system, sequential multiport fuel
system, VSC, ABS, electronic controlled
transmission, driver support system, engine
room junction block assy, tail lights, high
mounted stoplight, smart access system with
push-button start, shift lock system
25P/ S E AT F/ L30Po w e r s e a t s
26A/C-B7. 5Air conditioning system
27S/ROOF10Moon roof
28P/ S E AT F/ R30Po w e r s e a t s
29PSB30Pre-collision seat belt
30D/L-A M120Main body ECU
FuseAmpereCircuit