Page 637 of 860
637
GS450h_U (OM30D01U)6-3. Do-it-yourself maintenance
6
Maintenance and care
Engine compartment
■12-volt battery
P. 6 4 7
Engine oil level dipstick
(P. 6 3 9 )
Engine coolant reservoir (P. 6 4 2 )
Engine oil filler cap (P. 640)
Power control unit coolant res-
ervoir ( P. 6 4 2 )Brake fluid reservoir
(P. 645)
Fuse box ( P. 670)
Washer fluid tank ( P. 646)
Electric cooling fans
Condenser ( P. 644)
Radiator ( P. 644)1
2
3
4
5
6
7
8
9
10
Page 645 of 860

GS450h_U (OM30D01U)
6456-3. Do-it-yourself maintenance
6
Maintenance and care
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN”
lines on the tank.
■Adding fluid
Make sure to check the fluid type and prepare the necessary item.
■Brake fluid can absorb moisture from the air
Excess moisture in the brake fluid can cause a dangerous loss of braking efficiency.
Use only newly opened brake fluid.
Brake fluid
Fluid typeFMVSS No.116 DOT 3 or SAE J1703 brake fluid
ItemsClean funnel
CAUTION
■When filling the reservoir
Take care as brake fluid can harm your hands and eyes and damage painted sur-
faces.
If fluid gets on your hands or in your ey es, flush the affected area with clean water
immediately.
If you still experience discomfort, see a doctor.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level to go down slightly as the brake pads wear out
or when the fluid level in the accumulator is high.
If the reservoir needs frequent refil ling, there may be a serious problem.
Page 675 of 860
GS450h_U (OM30D01U)
6756-3. Do-it-yourself maintenance
6
Maintenance and care
11ABS MAIN 210Brake system
12ABS MAIN 110Brake system
13IGCT NO.130IGCT NO.2, IGCT NO.3, IGCT NO.4,
IGCT NO.5
14ECU-B7. 5Smart access system with push-button start
15INV W/P10Hybrid system
16ETCS10Multiport fuel injection system/sequential
multiport fuel injection system
17EPS-B10Electric power steering system
18D/C CUT30DOME, MPX-B
19HORN10Horn
20ODS5Occupant classification system
21TV7. 5Remote Touch screen
22P/ I - B N O. 280IG2 MAIN, EFI MAIN, EDU, F/PMP, A/F
23ABS NO.230ECB
24P/ I - B N O.150H-LP HI RH, H-LP HI LH, DRL
25H-LP LO30H-LP LO RH, H-LP LO LH
26LH J/B-B40Left-hand junction block
27RH J/B-B40Right-hand junction block
28VGRS40No circuit
29OIL PMP60Oil pump
30IGCT NO.57. 5Power management system, shift position
sensor
31WIP-S7. 5Windshield wipers, driver support system
32WA S H - S5Windshield washer, driver support system
33COMB SW5Windshield wipers
FuseAmpereCircuit
Page 677 of 860
GS450h_U (OM30D01U)
6776-3. Do-it-yourself maintenance
6
Maintenance and care
*: Low beam and high beam are the same bulb. (vehicles with discharge headlights)
52ABS NO.130ECB
53ECU-B NO.27. 5No circuit
54DEICER25Windshield wiper de-icer
55ABS MAIN 310Brake system
56FILTER10Condenser
57A/C W/P7. 5Air conditioning system
58SPARE10Spare fuse
59SPARE30Spare fuse
60SPARE20Spare fuse
FuseAmpereCircuit
Page 679 of 860
GS450h_U (OM30D01U)
6796-3. Do-it-yourself maintenance
6
Maintenance and care
11DOOR FL30Outside rear view mirror defoggers, power
window (front left-hand)
12CAPACITOR
(HV)10Capacitor
13STRG LOCK15Steering lock system
14D/L NO.225Power door lock system
15DOOR RL30Power window (rear left-hand)
16HAZ15Turn signal lights, emergency flashers
17LH-IG210
Multiport fuel injection system/sequential
multiport fuel injection system, stop lights,
smart access system with push-button start,
steering lock system, brake system, power
management system
18LH J/B-B7. 5Body ECU
19S/ROOF20Moon roof
20P/ S E AT 2 F/ L25Po w e r s e a t s
21TI & TE20Electric tilt and telescopic steering column
22A/C7. 5Air conditioning system
FuseAmpereCircuit
Page 682 of 860
682
GS450h_U (OM30D01U)
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
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
Page 683 of 860
GS450h_U (OM30D01U)
6836-3. 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
4ARS80No circuit
5MAIN220Engine compartment junction block
Page 701 of 860

701
GS450h_U (OM30D01U)
7When trouble arises
7-1. Essential information Emergency flashers................... 702
If your vehicle has to be stopped in an emergency .... 703 7-2. Steps to take in an emergency
If your vehicle needs to be towed ................................ 704
If you think something is wrong ................. 710
If a warning light turns on or a warning buzzer sounds ........ 711
If a warning message is displayed .................................. 721
If you have a flat tire.................... 749
If the hybrid system will not start................................. 762
If the shift lever cannot be shifted from P ......................764
If the parking brake cannot be released .................................765
If the electronic key does not operate properly ...................... 767
If the 12-volt battery is discharged ............................. 770
If your vehicle overheats .......... 774
If the vehicle becomes stuck ............................................. 778