Page 442 of 652

442
GS450h_OM_OM30E26U_(U)
6-3. Do-it-yourself maintenance
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 ve hicle. 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 th e hybrid system is operating. Also, be
sure all accessories are turned off.
Page 460 of 652
460
GS450h_OM_OM30E26U_(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 461 of 652

GS450h_OM_OM30E26U_(U)
4616-3. 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
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.
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 464 of 652
464
GS450h_OM_OM30E26U_(U)
6-3. Do-it-yourself maintenance
The upper part of the 12-volt battery
Pull the strap upwards to lift up
the 12-volt battery cover.
Remove the fuse with the pullout
tool.
Only type A fuse can be removed
using the pullout tool.
4
Page 468 of 652

468
GS450h_OM_OM30E26U_(U)
6-3. Do-it-yourself maintenance
34DOME7. 5
Personal lights, ornament lights, trunk light,
footwell lights, door courtesy lights, vanity
lights, rear door inside handle illuminations,
power trunk opener and closer
35MPX-B10
Body ECU, smart access system with push-
button start, electric tilt and telescopic steer-
ing column, power seats, head-up display,
front door ECU, gauges and meters, steer-
ing sensor, yaw rate and G sensor, overhead
module, RR CTRL SW, power trunk opener
and closer, clock, CAN gateway ECU
36IGCT NO.410Po w e r c o n t r o l u n i t
37IGCT NO.37. 5Hybrid battery (traction battery), DC/DC
converter
38IGCT NO.25Hybrid system
39IG2 NO.15DCM, CAN gateway ECU
40GAUGE5Gauges and meters
41DC/DC150RH-J/B DC/DC, P/I DC/DC,
LH-J/B DC/DC, LUG-J/B DC/DC
42P/ I D C / D C100RR S/SHADE, DEFOG, FOG, TAIL,
PA N E L
43RH J/B DC/DC80Right-hand junction block
44LH J/B DC/DC50Left-hand junction block
45H-LP CLN30Headlight cleaner
46FAN NO.240Electric cooling fans
47LUG J/B DC/DC80Luggage compartment junction block
48FAN NO.180Electric cooling fans
49PTC NO.150PTC heater
50PTC NO.250PTC heater
51HTR50Air conditioning system
FuseAmpereCircuit
Page 474 of 652
474
GS450h_OM_OM30E26U_(U)
6-3. Do-it-yourself maintenance
■Trunk
FuseAmpereCircuit
1PSB30Pre-collision seat belts
2PTL25Power trunk opener and closer
3RR J/B-B10Smart access system with push-button start
4RR S/HTR20Seat heaters (rear)
5FR S/HTR10Seat heaters/ventilators (front)
6RR FOG10No circuit
7DC/DC-S (HV)7. 5DC/DC converter
8BATT FAN (HV)20Hybrid battery (traction battery) cooling fan
system
9SECURITY7. 5SECURITY
10ECU-B NO.37. 5Parking brake
11TRK OPN7. 5Power trunk opener and closer, trunk open
motor
12DCM (HV)7. 5DCM
13AC INV (HV )20Po w e r o u t l e t ( 1 2 0 V AC )
14RR-IG15Radar sensor, Blind Spot Monitor
15RR ECU-IG10
Power trunk opener and closer, parking
brake, tension reducer (rear left-hand), RR
CTRL SW, tire pressure warning system
16EPS-IG5Electric power steering system
17BACK UP7. 5Back-up lights, Remote Touch screen
Page 475 of 652
GS450h_OM_OM30E26U_(U)
4756-3. Do-it-yourself maintenance
6
Maintenance and care
■The upper part of the 12-volt battery*
*
: When one or more of the fuses in this unit are blown, the unit needs to be replaced as a whole.
FuseAmpereCircuit
1EPB30Parking brake
2LUG-J/B BATT40Luggage compartment junction block
3EPS80Electric power steering
4ARS80Dynamic rear steering
5MAIN220Engine compartment junction block
Page 493 of 652

493
GS450h_OM_OM30E26U_(U)
7When trouble arises
7-1. Essential information Emergency flashers................... 494
If your vehicle has to be stopped in an emergency .... 495 7-2. Steps to take in an emergency
If your vehicle needs to be towed ................................ 496
If you think something is wrong ................502
If a warning light turns on or a warning buzzer sounds .....503
If a warning message is displayed ................................. 513
If you have a flat tire.................... 541
If the hybrid system will not start................................ 554
If the shift lever cannot be shifted from P ..................... 556
If the parking brake cannot be released ................................ 557
If the electronic key does not operate properly ..................... 559
If the 12-volt battery is discharged ............................. 562
If your vehicle overheats ......... 566
If the vehicle becomes stuck ...............................................571