Page 548 of 660

5487-2. Steps to take in an emergency
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■If “Maintenance Required Visit Your Dealer” is displayed (U.S.A. only)
Indicates that all maintenance is required 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. 466)
*: Refer to the separate “Scheduled Maintenance” 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. 536)
●“Antilock Brake System Malfunction Visit Your Dealer”:
The ABS warning light comes on. ( P. 537)
●“Charging System Malfunction See Ow ner's Manual” (F SPORT models):
The charging system warning light comes on. ( P. 536)
■Warning buzzer
P. 540
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.
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5567-2. Steps to take in an emergency
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WARNING
■When holding a tire with Selectable Color Trim (if equipped)
■Replacing a flat tire
●Do not touch the disc wheels or the area around the brakes immediately after the
vehicle has been driven.
After the vehicle has been driven the disc wheels and the area around the brakes will
be extremely hot. Touching these areas with hands, feet or other body parts while
changing a tire, etc. may result in burns.
●Failure to follow these precautions could cause the wheel nuts to loosen and the tire
to fall off, resulting in death or serious injury.
• Never use oil or grease on the wheel bolts or wheel nuts. Oil and grease may cause the wheel nuts to be excessively tightened, leading to
bolt or disc wheel damage. In addition, the oil or grease can cause the wheel nuts
to loosen and the wheel may fall off, causing a serious accident.
Remove any oil or grease from the wheel bolts or wheel nuts.
• Have the wheel nuts tightened with a torque wrench to 76 ft•lbf (103 N•m, 10.5 kgf•m) as soon as possible after changing wheels.
• When installing a tire, only use wheel nuts that have been specifically designed for
that wheel.
• If there are any cracks or deformations in the bolt screws, nut threads or bolt holes
of the wheel, have the vehicle inspected by your Lexus dealer.
■Replacing a flat tire for vehicles with power back door
In cases such as when replacing tires, make sure to turn off the power back door main
switch (P. 112). Failure to do so may cause the back door to operate unintentionally if
the power back door switch is accidentally touched, re sulting in hands and fingers
being caught and injured.
Do not hold the tire by the Selectable Color
Trim. Otherwise, the Selectable Color Trim
may be damaged or may fall off causing the tire
to drop, possibly causing injury.
Page 562 of 660

5627-2. Steps to take in an emergency
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One of the following may be the cause of the problem:
●The 12-volt battery may be discharged. (P. 568)
●One or both of the 12-volt battery terminals may be disconnected. ( P. 483)
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. 233, 245)
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
Page 563 of 660
5637-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U
Turn the power switch to ON mode and check that the parking brake is set.
( P. 233, 245)
Turn the power switch to ACCESSORY mode.
Depress the brake pedal.
Pry the cover up with a flathead
screwdriver or equivalent tool.
To prevent damage to the cover, cover
the tip of the scre wdriver with a rag.
Press the shift lock override button.
The shift lever can be shifted while the
button is pressed
If the shift lever cannot be shifted from P
If the shift lever cannot be shifted with your foot on the brake pedal, there may
be a problem with the shift lock system (a system to prevent accidental opera-
tion of the shift le ver). Have the vehicle inspecte d by your Lexus dealer imme-
diately.
The following steps may be used as an emergency measure to ensure that the
shift lever can be shifted:
1
2
3
4
5
Page 566 of 660
5667-2. Steps to take in an emergency
RX450h_U_OM0E013U
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.
In the event that the hybrid system still cannot be operated, contact your Lexus
dealer.
Starting the hybrid system
1
2
3
4
Page 567 of 660

5677-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U
■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. 506)
■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. 233)
■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. 610)
●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 power window or the moon roof or panoramic
moon roof.
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5707-2. Steps to take in an emergency
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Start 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 your 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 components when the vehicle is running at a low
speed for an extended period , such as in heavy traffic.
■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 before 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)
6
7
8
9
10
11
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5747-2. Steps to take in an emergency
RX450h_U_OM0E013U
■“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown on the multi-information displayStop the vehicle in a safe place and turn off the air conditioning system, and
then stop the hybrid system.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the hybrid system has
cooled down sufficiently, inspect
the hoses and radiator core (radi-
ator) for any leaks.Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact your Lexus
dealer.
The coolant level is satisfactory if
it is between the “FULL” and
“LOW” lines on the reservoir.Reservoir
“FULL” line
“LOW” line
Radiator cap
If your vehicle overheats
The following may indicate that your vehicle is overheating.
●The needle of the engine coolant temperature gauge ( P. 97) enters the
red zone, or a loss of hybrid system power is experienced. (For example, the
vehicle speed does not increase.)
●“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” or
“Hybrid System Overheated Reduced Output Power” is shown on the
multi-information display.
●Steam comes out from under the hood.
Correction procedures
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2
3
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2
4
1
2
3
4