Page 558 of 784
558
ES350_300h_OM_OM33B99U_(U)
7-3. Do-it-yourself maintenance
■Adding distilled waterRemove the vent plug.
Add distilled water.
If the “UPPER LEVEL” line cannot
be seen, check the fluid level by
looking directly at the cell.
Put the vent plug back on and close it securely.
■Before recharging
When recharging, the 12-volt battery prod uces hydrogen gas which is flammable
and explosive. Therefore, observe the following 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.
1
Low O.K.2
3
Page 591 of 784

ES350_300h_OM_OM33B99U_(U)
5917-3. Do-it-yourself maintenance
7
Maintenance and care
22EFI NO.3
10*2Multiport fuel injection system, sequential
multiport fuel system, air intake system,
exhaust system
7. 5*1Multiport fuel injection system, sequential
multiport fuel system, air intake system
23INJ7. 5Multiport fuel injection system, sequential
multiport fuel system
24ECU-IG2 NO.37. 5
Multiport fuel injection system, sequential
multiport fuel system, electronic controlled
transmission, power management system,
steering lock system, cruise control system
25IGN15Starting system
26D/L-AM225Power door lock system
27IG2-MAIN25INJ, IGN
28ALT-S*27. 5Charging system
DC/DC-S*17. 5Hybrid system
29MAYDAY5MAYDAY
30TURN&HAZ15Turn signal lights, emergency flashers
31STRG LOCK10Steering lock system
32AMP30Audio system
33H-LP LH-LO15Left-hand headlight
34H-LP RH-LO15Right-hand headlight
35EFI-MAIN NO.130EFI NO.2, EFI NO.3, fuel system
36SMART5Smart access system with push-button start,
occupant classification system
37ETCS10Multiport fuel injection system, sequential
multiport fuel system
38ABS NO.2*17. 5VSC, ABS
39EFI NO.17. 5
Multiport fuel injection system, sequential
multiport fuel system, electronic controlled
transmission
FuseAmpereCircuit
Page 592 of 784
592
ES350_300h_OM_OM33B99U_(U)
7-3. 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
illumination
43DOME7. 5
Clock, footwell lights, vanity lights, ornament
lights, personal lights, door courtesy lights,
outer foot 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
Page 594 of 784

594
ES350_300h_OM_OM33B99U_(U)
7-3. Do-it-yourself maintenance
■Driver’s side instrument panel
FuseAmpereCircuit
1ECU-IG1 NO.210
Main body ECU, audio system, shift lock sys-
tem, outside mirror control ECU, tension
reducer, windshield wipers, heated steering
wheel, multi-information display, audio dis-
play, intuitive parking assist, tire pressure
warning system, moon roof, auto anti-glare
inside rear view mirror, raindrop sensor, rear
sunshade, wireless door lock system, power
trunk opener and closer ECU
2ECU-IG1 NO.110
Electric cooling fan, windshield wiper de-
icer, VSC, ABS, charging system, steering
sensor, electronic controlled transmission,
electric power steering, gateway ECU, elec-
tric tilt and telescopic steering column
3PA N E L N O. 25Clock
4TA I L15Parking lights, side marker lights, license
plate lights
5DOOR F/R20Power window, outside mirror control ECU
6DOOR R/R20Po w e r w i n d o w
7DOOR F/L20Power window, outside mirror control ECU
8DOOR R/L20Po w e r w i n d o w
9H-LP LVL7. 5Automatic headlight leveling system
10WA S H E R10Windshield washer
11A/C-IG17. 5Air conditioning system, PTC heater, gauges
and meters, seat heaters and ventilators
Page 595 of 784

ES350_300h_OM_OM33B99U_(U)
5957-3. Do-it-yourself maintenance
7
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/HTR&FAN F/R10Seat heaters and ventilators
19S/HTR&FAN 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-AM120Main body ECU, power door lock system
FuseAmpereCircuit
Page 596 of 784
596
ES350_300h_OM_OM33B99U_(U)
7-3. Do-it-yourself maintenance
31TI&TE20Electric tilt and telescopic steering column
32A/B10Occupant classification system, SRS airbag
system
33ECU-IG2 NO.17. 5Gauges and meters
34ECU-IG2 NO.27. 5VSC, ABS, gateway ECU, smart access sys-
tem with push-button start
35CIG& P/OUTLET15Po w e r o u t l e t
36ECU-ACC7. 5Main body ECU, gauges and meters, outside
rear view mirrors
37ECU-IG1 NO.310
Intuitive parking assist, driver support sys-
tem, skid control buzzer, Blind Spot Monitor,
radar sensor
38S/HTR RR20No circuit
FuseAmpereCircuit
Page 600 of 784
600
ES350_300h_OM_OM33B99U_(U)
7-3. Do-it-yourself maintenance
■Headlight high beamTurn the bulb base counter-
clockwise.
Unplug the connector while
pressing the lock release.
Exchange the light bulb, and
install the bulb base.
Align the 3 tabs on the light bulb
with the mounting, and insert.
Turn and secure the bulb base.
Shake the bulb base gently to
check that it is not loose, turn the
headlights on once and visually
confirm that no light is leaking
through the mounting.
Replacing light bulbs
1
2
3
4
Page 601 of 784
ES350_300h_OM_OM33B99U_(U)
6017-3. Do-it-yourself maintenance
7
Maintenance and care
■Headlight low beam (halogen bulb)Turn the bulb base counter-
clockwise.
Unplug the connector while
pressing the lock release.
Exchange the light bulb, and
install the bulb base.
Align the 3 tabs on the light bulb
with the mounting, and insert.
Turn and secure the bulb base.
Shake the bulb base gently to
check that it is not loose, turn the
headlights on once and visually
confirm that no light is leaking
through the mounting.
1
2
3
4