battery LEXUS RX450H 2016 Repair Manual

4866-3. Do-it-yourself maintenance
RX450h_U_OM0E013U
WARNING
■When disconnecting the 12-volt battery
NOTICE
■When recharging the 12-volt battery
Never recharge the 12-volt battery while the hybrid system is operating. Also, be sure
all accessories are turned off.
Do not disconnect the negative (-) terminal on
the body side as shown. The disconnected neg-
ative (-) terminal may touch the positive (+) ter-
minal, which may cause a short and result in
death or serious injury.

5066-3. Do-it-yourself maintenance
RX450h_U_OM0E013U
●Flathead screwdriver
●Lithium battery CR2032
Take out the mechanical key.
Remove the cover.
To prevent damage to the key, cover the
tip of the flathead screwdriver with a
tape.
Remove the depleted battery.
Insert a new battery with the “+” termi-
nal facing up.
Electronic key battery
Replace the battery with a new one if it is depleted.
You will need the following items:
Replacing the battery
1
2
3

5076-3. Do-it-yourself maintenance
6
Maintenance and care
RX450h_U_OM0E013U
■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 the 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.
WARNING
■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 coul d 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 co mponent inside the remote control.
●Do not bend either of the battery terminals.

5096-3. Do-it-yourself maintenance
6
Maintenance and care
RX450h_U_OM0E013U
Luggage compartment (type A fuse box)
Remove the 12-volt battery cover.
( P. 483)
Luggage compartment (type B fuse box)
Remove the terminal cover.
Remove the fuse with the pullout
tool.
Only some fuses can be removed
using the pullout tool.
Check 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.
3
4
1
2

527
7When trouble arises
RX450h_U_OM0E013U
7-1. Essential informationEmergency flashers ..................528
If your vehicle has to be stopped in an
emergency................................. 529
7-2. Steps to take in an emergency
If your vehicle needs to be towed ...........................................530
If you think something is wrong ...........................................535
If a warning light turns on or a warning buzzer
sounds.......................................... 536
If a warning message is displayed..................................... 543
If you have a flat tire .................. 549
If the hybrid sy stem will not
start ................................................ 561
If the shift lever cannot be shifted from P............................ 563
If the electronic key does not operate properly ............. 564
If the 12-volt battery is discharged .................................568
If your vehicle overheats ......... 574
If the vehicle becomes stuck ............................................. 578

528
RX450h_U_OM0E013U7-1. Essential information
Press the switch.
All the turn signal lights 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 operat-
ing (while the “READY” indicator is not illu minated), the 12-volt battery may discharge.
Emergency flashers
The emergency flashers are used to warn other drivers when the vehicle has
to be stopped in the road due to a breakdown, etc.

5397-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U
*: Driver’s and front passenger’s seat belt warning buzzer:The driver’s seat belt warning buzzer sounds to alert the driver that his or her seat belt
is not fastened. Once the power switch is turned to ON mode, the buzzer sounds for
6 seconds. If the vehicle reaches a speed of 12 mph (20 km/h), the buzzer sounds
once. If the seat belt is still unfastened af ter 24 seconds, the buzzer will sound inter-
mittently for 10 seconds. Then, if the seat belt is still unfastened, the buzzer will sound
in a different tone for 20 more seconds.
The front passenger’s seat belt warning buzzer sounds to alert the front passenger
that his or her seat belt is not fastened. Th e buzzer sounds once if the vehicle reaches
a speed of 12 mph (20 km/h). If the seat belt is still unfastened after 24 seconds, the
buzzer will sound intermittently for 10 seconds. Then, if the seat belt is still unfastened,
the buzzer will sound in a different tone for 20 more seconds.
■SRS warning light
This warning light system monitors the airbag sensor assembly, front impact sensors, side
impact sensors (front door), side impact se nsors (rear), driver’s seat position sensor,
driver’s seat belt buckle sw itch, front passenger occupant classification system (ECU and
sensors), “AIR BAG ON” indicator light, “A IR BAG OFF” indicator light, front passen-
ger’s seat belt buckle switch, driver’s seat belt pretension er, front passenger’s seat belt
pretensioner and force limiter, airbags, in terconnecting wiring and power sources.
(  P. 38)
■Front passenger detection sensor, seat belt reminder and warning buzzer
●If luggage is placed on the front passenger seat, the front passenger detection sensor
may cause the warning light to flash and the warning buzzer to sound even if a passen-
ger is not sittin g in the seat.
●If a cushion is placed on the seat, the sens or may not detect a passenger, and the warn-
ing light may not operate properly.
■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 warning buzzer
may sound.
■If the malfunction indicator lamp comes on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fu el 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 severa l trips, contact your Lexus dealer as soon as
possible.

5447-2. Steps to take in an emergency
RX450h_U_OM0E013U
*: A buzzer sounds the first time a message is shown on the multi-information display.
●If the following messages are shown, there may be a malfunction.
Immediately stop the vehicle in a safe place and contact your Lexus dealer.
Continuing to drive the vehicle may be dangerous. • “Braking Power Low Stop in a Safe Place See Owner’s Manual”
• “Oil Pressure Low Stop in a Safe Place See Owner’s Manual”
• “Charging System Malfunction See Owner’s Manual”
●If the following messages are shown, there may be a malfunction.
Immediately have the vehicle inspected by your Lexus dealer.• “Hybrid System Malfunction”
•“Check Engine”
• “Hybrid Battery System Malfunction”
• “Accelerator System Malfunction”
• “Access System with Elec. Key Malfunction See Owner’s Manual”
●If “Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown, following the instructions, accordingly. ( P. 574)
FlashesSounds
Indicates a situation, such as when
damage to the vehicle or danger may
result
Comes
onDoes not sound
Indicates a condition, such as malfunc-
tion of electrical components, their
condition, or indicates the need for
maintenance
FlashesDoes not sound
Indicates a situation, such as when an
operation has been performed incor-
rectly, or indicates how to perform an
operation correctly
If a message instructing to refer to the Owner’s Manual is displayed
System
warning
lightWarning buzzer*Warning

5457-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U
Take the appropriate actions as instructed in the message displayed.
If any of the following messages are displa yed, also refer to this Owner’s Manual.
■If “Hybrid System Overheated Reduced Output Power” is shown
This message may be displayed when driving under severe operating condi-
tions.
(For example, when driving up a long steep hill.)
Handling method: P. 574
■If “Hybrid Battery Low Shift Ou t of N to Recharge” is shown
Message is displayed when the remainin g charge for the hybrid battery (trac-
tion battery) is low.
As the hybrid battery (traction battery) cannot be charged when the shift
lever is in N, when stopped for long periods of time shift the shift lever to P.
■If “Hybrid Battery Low Hybrid System Stopped Shift to P and Restart” is
shown
Message is displayed when the remainin g charge for the hybrid battery (trac-
tion battery) is low, because vehicle has been shifted N for a long period of
time.
When operating the vehicle, restart the hybrid system.
■If “Shift to P Before Exiting Vehicle” is shown
Message is displayed when the driver’s door is opened without turning the
power switch off with the shift lever in any position other than P.
Shift the shift lever to P.
Other messages displayed on the multi-information display

5467-2. Steps to take in an emergency
RX450h_U_OM0E013U
■If “Shift Is in N Release Accelerator Before Shifting” is shown
Message is displayed when the accelerator pedal has been depressed and
the shift lever is in N. Release the accelerator pedal and shift the shift lever to
D or R.
■If “Depress Brake when Vehicle Is Stopped Hybrid System May Overheat”
is shown
Message is displayed when the accelerato r pedal is depressed to maintain the
vehicle position when stopped on a upward slope, etc.
If this continues, the hybrid system may overheat.
Release the accelerator pedal and depress the brake pedal.
■If “Power Turned Off to Save Battery” is displayed
This message is displayed when the power was cut off due to the automatic
power off function.
The next time the hybrid system is star ted, increase the engine speed slightly
and maintain it at that speed for approximately 5 minutes to recharge the 12-
volt battery.
■If “A New Key has been Registered Contact Your Dealer for Details” is dis-
played
This message will be displayed each time the driver's door is opened when the
doors are unlocked from the outside fo r approximately one week after a new
electronic key has been registered.
If this message is displayed but you ha ve not had a new electronic key regis-
tered, ask your Lexus dealer to check if an unknown electronic key (other than
those in your possession) has been registered.
■When “Headlight System Malfunction Visit Your Dealer” is displayed
The following systems may be malfunct ioning. Have the vehicle inspected by
your Lexus dealer immediately.
●The LED headlight system
●The automatic headlight leveling system
●Automatic High Beam (if equipped)
●AFS (Adaptive Front-lighting System) (if equipped)