LEXUS RX450h 2018 Owners Manual

6918-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85UOne of the following may be the cause of the problem: ●
The 12-volt battery may be discharged. ( → P. 695)●
One or both of the 12-volt battery terminals may be disconnected. ( → P. 605)Contact your Lexus dealer if the problem cannot be repaired, or if repair procedures
are unknown.
When the hybrid system does not start, the following steps can be used as an
interim measure to start the hybrid system if the power switch is functioning nor-
mally.
Do not use this starting procedur e except in cases of emergency.
Turn the power switch to ON mode an d check that the parking brake is set.
( → P. 240, 253)
Shift the shift lever to P.
Turn the power switch to ACCESSORY mode.
Press and hold the power switch for ab out 15 seconds while depressing the
brake pedal firmly.
Even if the hybrid system can be starte d using the above steps, the system may
be malfunctioning. Have the vehicle inspected by your Lexus dealer.The interior lights and headlights do not turn on, or the horn does not
sound.
Emergency start function 1
2
3
4

692 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U■
Unlocking the door
Use the mechanical key ( → P. 133) in order to perform the following opera-
tions:
Insert the mechanical key while
pulling on the driver’s door han-
dle.
Unlocking the door. Turning the key rearward unlocks the
driver’s door. Turning the key again
unlocks the other doors.
Remove the key, return the handle, and then pull the handle again.If the electronic key does not operate properly If communication between the electronic key and vehicle is interrupted
( → P. 160) or the electronic key ca nnot be used because the battery is
depleted, the smart access system wi th push-button start and wireless
remote control cannot be used. In such cases, the doors can be opened and
the hybrid system can be started by following the procedure below.
Locking and unlocking the doors 1
2
3

6938-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85U■
Locking the door
With the door open, push down
the inside lock button.
Close the door. ■
Key linked functions
Ensure that the shift lever is in P and depress the brake pedal.
Touch the Lexus emblem side of the
electronic key to the power switch. When the electronic key is detected, a
buzzer sounds and the power switch will
turn to ON mode.
When the smart access system with
push-button start is deactivated in cus-
tomization setting, the power switch will
turn to ACCESSORY mode.
Firmly depress the brake pedal and check that is shown on the multi-
information display.
Press the power switch shortly and firmly.
In the event that the hybrid system still cannot be operated, contact your Lexus
dealer. 1
Closes the windows and the moon roof
* or
panoramic moon roof
* (turn and hold)
Opens the windows and the moon roof
* or
panoramic moon roof
* (turn and hold)
These settings must be customized at your
Lexus dealer.
* : If equipped
Starting the hybrid system 2 1
2
1
2
3
4

694 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U■
Stopping the hybrid system
Shift the shift lever to P, set the parking brake, and press the power switch as you normally
do when stopping the hybrid system. ■
Replacing the key battery
As the above procedure is a temporary measure, it is recommended that the electronic
key battery be replaced immediately when the battery is depleted. ( → P. 630)■
Changing power switch modes
Release the brake pedal and press the power switch in step above.
The hybrid system does not start and modes will be changed each time the switch is
pressed. ( → P. 240)■
When the electronic key does not work properly ●
Make sure that the smart access system wi th push-button start has not been deacti-
vated in the customization setting. If it is off, turn the function on.
(Customizable features → P. 740)●
Check if battery-saving mode is set. If it is set, cancel the function. ( → P. 160)
WARNING ■
When using the mechanical key and operating the power windows or the moon roof
or panoramic moon roof
Operate the power window or the moon roof or panoramic moon roof after checking
to make sure that there is no possibility of any passenger having an y of their body parts
caught in the window or the moon roof or panoramic moon roof.
Also, do not allow children to op erate the mechanical key. It is possible for children and
other passengers to get caught in the powe r window or the moon roof or panoramic
moon roof. 3

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
2
3

696 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85URemove the engine cover.
Connect the jumper cables accordin g to the following procedure:
Connect a positive jumper cable clamp to the exclusive jump starting ter-
minal on your vehicle.
Connect the clamp on the other end of the positive cable to the positive (+)
battery terminal on the second vehicle.
Connect a negative cable clamp to the negative (-) battery terminal on the
second vehicle.
Connect the clamp at the other end of th e negative cable to a solid, station-
ary, unpainted meta llic point away from the excl usive jump starting terminal
and any moving parts, as shown in the illustration. 4
5
1
2
3
4

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
7
8
9
10
11

698 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U■
Charging the 12-volt battery
The electricity stored in the 12-volt battery w ill discharge gradually even when the vehicle
is not in use, due to natural discharge and the draining effects of certain electrical appli-
ances. If the vehicle is left for a long time, the 12-volt battery may discharge, and the
hybrid system may be unable to start. (The 12-volt battery recharges automatically while
the hybrid system is operating.) ■
When the 12-volt battery is removed or discharged ●
In some cases, it may not be possible to un lock the doors using the smart access system
with push-button start when the 12-volt battery is discharged. Use the wireless remote
control or the mechanical key to lock or unlock the doors.●
The hybrid system may not start on the first attempt after the 12-volt battery has
recharged but will start normally after the second attempt. This is not a malfunction. ●
The power switch mode is memorized by the vehicle. When the 12-volt battery is
reconnected, the system will retu rn to the mode it was in be fore the 12-volt battery was
discharged. Before disconnect ing the 12-volt battery, turn the power switch off.
If you are unsure what mode the power switch was in before the 12-volt battery dis-
charged, be especially careful when reconnecting the 12-volt battery. ●
The power back door must be initialized. ( → P. 150)■
When replacing the 12-volt battery ●
RX450h: Use a Central Degassing type 12 -volt battery (European Regulations).
RX450hL: Use a 12-volt battery designed for this vehicle. ●
RX450h: Use a 12-volt battery that the case size is same as the previous one (LN2),
20 hour rate capacity (20HR) is equivalent (60Ah) or greater, and performance rating
(CCA) is equivalent (460A) or greater.
• If the sizes differ, the 12-volt battery cannot be properly secured.
• If the 20 hour rate capacity is low, even if the time period where the vehicle is not
used is a short time, the 12-volt battery may discharge and the hybrid system may
not be able to start.

6998-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85U●
Use a 12-volt battery with a handle. If a 12-volt battery without a handle is used, removal
is more difficult. ●
After replacing, firmly attach the following items to the exhaust hole of the 12-volt bat-
tery.
• Use the exhaust hose that was attached to
the 12-volt battery before replacing and
confirm that it is firmly connected to the
hole section of the vehicle.
• Use the exhaust hole plug included with the
12-volt battery replaced or the one installed
on the 12-volt battery prior to the replace-
ment. (Depending on the 12-volt battery to
be replaced, the exhaust hole may be
plugged.)
Exhaust hole plug
Exhaust hole
Exhaust hose
Hole section of the vehicle 
RX450h
For details, consult your Lexus dealer. 
RX450hL
WARNING ■
When removing the battery terminals
Always remove the negative (-) terminal first. If the positive (+) terminal contacts any
metal in the surrounding area when the posi tive (+) terminal is removed, a spark may
occur, leading to a fire in addition to el ectrical shocks and de ath or serious injury.1
2
3
4

700 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85UWARNING ■
Avoiding 12-volt battery fires or explosions
Observe the following precautions to preven t accidentally igniting the flammable gas
that may be emitted from the 12-volt battery: ●
Make sure each jumper cable is connected to the correct terminal and that it is not
unintentionally in contact with any other than the intended terminal.●
Do not allow the other end of the jumper cab le connected to the “+” terminal to come
into contact with any other parts or metal surfaces in the area, such as brackets or
unpainted metal. ●
Do not allow the + and - clamps of the jump er cables to come in to contact with each
other. ●
Do not smoke, use matches, cigarette light ers or allow open flame near the 12-volt
battery. ■
12-volt battery precautions
The 12-volt battery contains poisonous and co rrosive acidic electr olyte, while related
parts contain lead and lead compounds. Ob serve the following precautions when han-
dling the 12-volt battery: ●
When working with the 12-volt battery, always wear safety glasses and take care not
to allow any battery fluids (acid) to come in to contact with skin, clothing or the vehicle
body. ●
Do not lean over the 12-volt battery. ●
In the event that battery fluid comes into contact with the skin or eyes, immediately
wash the affected area with water and seek medical attention.
Place a wet sponge or cloth over the affected area until medical attention can be
received. ●
Always wash your hands after handling the 12-volt battery support, terminals, and
other battery-related parts. ●
Do not allow children near the 12-volt battery. ■
After recharging the 12-volt battery
Have the 12-volt battery inspected at yo ur Lexus dealer as soon as possible.
If the 12-volt battery is deteriorating, continued use may cause the 12-volt battery to
emit a malodorous gas, which may be de trimental to the health of passengers.■
When replacing the 12-volt battery ●
When the vent plug and indicator are close to the hold down clamp, the battery fluid
(sulfuric acid) may leak. ●
For information regarding 12-volt battery replacement, contact your Lexus dealer.●
Make sure to replace the 12-volt battery with one designed for this vehicle. Other-
wise, hydrogen gas may enter the vehicle, possibly causing a fire or explosion. ●
After replacing, securely attach the exhaust hose and exhaust hole plug to the
exhaust hole of the replaced 12-volt battery. If not properly installed, gases (hydro-
gen) may leak into the vehicle interior, an d there is the possible danger of the gas
igniting and exploding.