Page 672 of 860
672
GS450h_U (OM30D01U)
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 676 of 860

676
GS450h_U (OM30D01U)
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
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 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
Page 702 of 860
702
GS450h_U (OM30D01U)
7-1. Essential information
Emergency flashers
Press the switch.
All the turn signals will flash.
To turn them off, press the switch once
again.
■Emergency flashers
If the emergency flashers are used for a long time while the hybrid system is not
operating (while the “READY” indicator is not illuminated), the 12-volt battery may
discharge.
The emergency flashers are used to warn other drivers when the vehi-
cle has to be stopped in the road to a breakdown, etc.
Page 716 of 860

7167-2. Steps to take in an emergency
GS450h_U (OM30D01U)
■SRS warning light
This warning light system monitors the airbag sensor assembly, front impact sensors,
side impact sensors (front door), side impact sensors (front), side impact sensors
(rear), driver’s seat position sensor, driver’s seat belt buckle switch, front passenger
occupant classification system, “AIR BAG ON” indicator light, “AIR BAG OFF” indi-
cator light, front passenger’s seat belt buckle switch, seat belt pretensioner assem-
blies, airbags, interconnectin g wiring and power sources. ( P. 4 0 )
■Front passenger detection sensor, seat belt reminder and warning buzzer
If luggage is placed on the front passen ger seat, the front passenger detection sen-
sor may cause the warning light to flash and the warning buzzer to sound even if a
passenger is not sitting in the seat.
■If the malfunction indicator lamp comes on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fuel tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go off after several driving trips.
If the light does not go off even after several trips, contact your Lexus dealer as soon
as possible.
■Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insufficient of the voltage temporarily
drops, the electric power steering system warning light may come on and the warn-
ing buzzer may sound.
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level. Pushing the tire
pressure warning reset switch will not turn off the tire pressure warning light.
Page 732 of 860
7327-2. Steps to take in an emergency
GS450h_U (OM30D01U)
Indicates that the hybrid
battery (traction battery)
is low
When stopping the vehi-
cle for a long period of
time, shift the shift lever to
P. The battery cannot be
charged with the shift
lever in N.
Indicates that the hybrid
battery (traction battery)
power has dropped
because a long period of
time has elapsed after
shifting the shift lever to
N
Restart the hybrid system
when starting the vehicle.
Indicates that the gaso-
line engine cannot oper-
ate or the shift lever is in
N for a long time
Stop the vehicle and shift
the shift lever to P.
Indicates that the accel-
erator pedal is depressed
while the shift position is
in NRelease the accelerator
pedal and shift the shift
lever to D or R.
Wa r n i n g m e s s a g eDetailsCorrection procedure
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