2018 LEXUS RX450h fuse

632 7-3. Do-it-yourself maintenance
RX450h_RX450hL _U_OM48F85UTurn the power switch off.
Open the fuse box cover. ■
Engine compartment
Push the tab in and lift the lid off.
■
Driver’s side instrument panel
Remove the lid.Checking and replacing fuses If any of the electrical components do not operate, a fuse may have blown. If
this happens, check and repl ace the fuses as necessary.1
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6337-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL _U_OM48F85U■
Luggage compartment (type A fuse box)
■
Luggage compartment (type B fuse box)
Remove the fuse with the pullout
tool.
Only some fuses can be removed
using the pullout tool. 
RX450h 
RX450hL
Remove the 12-volt battery cover.
( → P. 606) Remove the deck board and side aux-
iliary box cover and 12-volt battery
cover. ( → P. 606)
RX450h 
RX450hL
Remove the terminal cover. Remove the terminal cover. 3

634 7-3. Do-it-yourself maintenance
RX450h_RX450hL _U_OM48F85UCheck if the fuse is blown.
Normal fuse
Blown fuse Replace the blown fuse with a new
fuse of an appropriate amperage rat-
ing. The amperage rating can be
found on the fuse box lid.
Many types of fuse are used on this
vehicle. This illustration shows a com-
mon type of fuse used on this vehicle.■
After a fuse is replaced ●
If the lights do not turn on even after the fuse has been replaced, a bulb may need
replacement. ( → P. 637)●
If the replaced fuse blows again, have th e vehicle inspected by your Lexus dealer.■
If there is an overload in a circuit
The fuses are designed to blow, protec ting the wiring ha rness from damage.■
When replacing light bulbs
Lexus recommends that you use genuine Lexus products designed for this vehicle.
Because certain bulbs are conne cted to circuits designed to prevent overload, nongenu-
ine parts or parts not designed for this vehicle may be unusable. 4
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WARNING ■
To prevent system breakdowns and vehicle fire
Observe the following precautions.
Failure to do so may cause damage to th e vehicle, and possibly a fire or injury.●
Never use a fuse of a higher amperage rating than that indicated, or use any other
object in place of a fuse. ●
Always use a genuine Lexus fuse or equivalent.
Never replace a fuse with a wi re, even as a temporary fix.●
Do not modify the fuses or fuse boxes. ■
Fuse box near the power control unit
Never check or replace the fuses as there are high volt age parts and wiring near the
fuse box.
Doing so may cause electric shock, re sulting in death or serious injury.
NOTICE ■
Before replacing fuses
Have the cause of electrical overload determined and repaired by your Lexus dealer as
soon as possible.

690 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85UOne of the following may be the cause of the problem: ●
The electronic key may not be functioning properly.
( → P. 692)●
There may not be sufficient fuel in the vehicle’s tank.
Refuel the vehicle. ●
There may be a malfunction in the immobilizer system. ( → P. 83)●
There may be a malfunction in the steering lock system. ●
The hybrid system may be malfunctioni ng due to an electrical problem such
as electronic key battery depletion or a blown fuse. However, depending on
the type of malfunction, an interim meas ure is available to start the hybrid sys-
tem. ( → P. 691)
One of the following may be the cause of the problem: ●
The 12-volt battery may be discharged. ( → P. 695)●
The 12-volt battery terminal connections may be loose or corroded.
( → P. 691)If the hybrid system will not start Reasons for the hybrid system not star ting vary depending on the situation.
Check the following and perform the appropriate procedure:
The hybrid system will no t start even though the correct starting proce-
dure is being followed. ( → P. 239)
The interior lights and headlights are d im, or the horn does not sound or
sounds at a low volume.

6958-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85UIf you have a set of jumper (or booster) cables and a second vehicle with a 12-volt
battery, you can jump start your vehicle by following the steps below.
Confirm that the electronic key is
being carried. When connecting the jumper (or
booster) cables, depe nding on the situa-
tion, the alarm may activate and doors
locked. (
→ P. 87)
Open the hood ( → P. 595) and fuse
box cover.
Open the exclusive jump starting
terminal cover.If the 12-volt battery is discharged The following procedures may be used to start the hybrid system if the vehi-
cle’s 12-volt battery is discharged.
You can also call your Lexus deal er or a qualified repair shop.1
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6978-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85UStart the engine of the second vehicle. Increase the engine speed slightly and
maintain at that level for approximatel y 5 minutes to recharge the 12-volt bat-
tery of your vehicle.
Open and close any of the doors of yo ur vehicle with the power switch off.
Maintain the engine speed of the seco nd vehicle and start the hybrid system
of your vehicle by turning th e power switch to ON mode.
Make sure the “READY” indicator comes on. If the indicator light does not
come on, contact your Lexus dealer.
Once the hybrid system has started, remove the jumper cables in the exact
reverse order from which they were connected.
Close the exclusive jump starting termin al cover, and reinstall the fuse box
cover to its original position.
Once the hybrid system starts, have th e vehicle inspected at your Lexus dealer
as soon as possible. ■
Starting the hybrid system when the 12-volt battery is discharged
The hybrid system cannot be started by push-starting. ■
To prevent 12-volt battery discharge ●
Turn off the headlights and the audio system while the hybrid system is off. ●
Turn off any unnecessary electrical componen ts when the vehicle is running at a low
speed for an extended period , such as in heavy traffic.■
When removing the battery terminals
When the battery terminals are removed, the information stored in the ECU is cleared.
Before removing the battery termin als, contact your Lexus dealer.6
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777Alphabetical index
RX450h_RX450hL _U_OM48F85UFlat tire ...................................................... 673
Floor mats ................................................... 28
Fluid
Brake ..........................................................716
Transmission...........................................716
Washer .................................................. 604
Fog lights
Replacing light bulbs ........................637
Switch.......................................................266
Front automatic air
conditioning system ......................... 507
Front passenger footwell
hooks ...................................................... 557
Front passenger occupant
classification system .............................47
Front passenger’s seat belt
reminder light ..................................... 662
Front seat heaters................................. 526
Front seats ................................................. 167
Adjustment ..............................................167
Cleaning ................................................ 584
Correct driving posture ....................30
Driving position memory .................. 181
Head restraints ..................................... 186
Power easy access system .............. 181
Seat heaters ..........................................526
Seat position memory......................... 181
Front side marker lights
Light switch .......................................... 258
Replacing light bulbs ........................637
Wattage ....................................................719 Front turn signal lights
Replacing light bulbs ....................... 637
Turn signal lever ................................. 252
Wattage ................................................... 719
Fuel
Capacity................................................... 712
Fuel gauge ............................................... 96
Information............................................ 720
Refueling .................................................274
Type............................................................ 712
Fuel filler door......................................... 274
Refueling .................................................274
When the fuel filler door
cannot be opened ..........................277
Fuses...........................................................632
Garage door opener.......................... 560
Gauges.........................................................96
Glove box ............................................... 534
Grocery bag hooks............................... 541F
G

784 Alphabetical index
RX450h_RX450hL _U_OM48F85URadar cruise control
(dynamic radar cruise control
with full-speed range) ..................... 306
Radiator .................................................... 602
Radio.......................................................... 426
Rear automatic air conditioning
system .................................................... 522
Rear Cross Traffic Alert ......................319
Rear Cross Traffic Auto
Brake ...................................................... 356
Rear door sunshades .......................... 557
Rear passengers’ seat belt
reminder light ..................................... 662
Rear seat
Folding down the rear
seatbacks ............................................. 168
Rear side marker lights
Light switch .......................................... 258
Replacing light bulbs ........................637
Rear turn signal lights
Replacing light bulbs ........................637
Turn signal lever ................................. 252
Wattage ....................................................719 Rear view mirror
Inside rear view mirror....................... 191
Outside rear view mirrors ..............193
Rear window defogger ........................ 516
Rear window wiper .............................. 272
Refueling................................................... 274
Capacity................................................... 712
Fuel types................................................. 712
Opening the fuel tank cap .............274
When the fuel filler door
cannot be opened ..........................277
Regenerative braking............................. 76
Remote Touch
* .................................... 500
Replacing
Electronic key battery .....................630
Fuses ........................................................ 632
Light bulbs............................................. 637
Tires .......................................................... 673
Windshield wiper inserts ............... 628
Reporting safety defects
for U.S. owners ...................................752
Resetting the message indicating
maintenance is required ................ 588
Rev indicator ............................................. 98
Rev peak ..................................................... 98
Road accident cautions .......................... 81R