2018 LEXUS RX450h battery

670 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U■
If “Shift Is in N Release Accele rator Before Shifting” is shown
Message is displayed when the accele rator 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 appr oximately 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 Malfunctio n 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 ●
AFS (Adaptive Front-lighting System) (if equipped)

672 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U■
If “Maintenance Required Visit Your Dealer” is displayed (U.S.A. only)
Indicates that all maintenance is requir ed to correspond to the driven distance
on the maintenance schedule
* .
Comes on approximately 5000 miles (8000 km) after the message has
been reset.
(The indicator will not work properly unless the message has been reset.)
Perform the necessary maintenance. Please reset the message after the main-
tenance is performed. ( → P. 588)
* : Refer to the separate “Scheduled Mainte nance” or “Owner’s Manual Supplement”
for the maintenance interval applicable to your vehicle. ■
System warning lights
The master warning light does not come on or flash in the following cases. Instead, a sep-
arate system warning light will come on along with a message shown on the multi-infor-
mation display. ●
“Braking Power Low Visit Your Dealer”:
The brake system warning light (yellow) come on. ( → P. 660)●
“Antilock Brake System Malfunction Visit Your Dealer”:
The ABS warning light comes on. ( → P. 661)●
“Charging System Malfunction See Ow ner's Manual” (F SPORT models):
The charging system wa rning light comes on. ( → P. 660)■
Warning buzzer
→ P. 665
NOTICE ■
“High Power Consumption Partial Limit On AC/Heater Operation” is frequently
shown
There is a possible malfunction relating to the charging system or the 12-volt battery
may be deteriorating. Have the vehicle inspected by your Lexus dealer.

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.

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

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
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2
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