
5357-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U ●
Fluid leaks under the vehicle
(Water dripping from the air co nditioning after use is normal.)●
Flat-looking tires or uneven tire wear ●
Engine coolant temperature gauge needle continually points higher than nor-
mal ●
Changes in exhaust sound ●
Excessive tire squeal when cornering ●
Strange noises related to the suspension system ●
Pinging or other noises related to the hybrid system ●
Engine missing, stumbling or running roughly ●
Appreciable loss of power ●
Vehicle pulls heavily to one side when braking ●
Vehicle pulls heavily to one side when driving on a level road ●
Loss of brake effectiveness, spongy f eeling, pedal almost touches the floorIf you think something is wrong If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

536 7-2. Steps to take in an emergency
RX450h_U_OM0E013UIf a warning light turns on or a warning buzzer
sounds Calmly perform the following actions if any of the warning lights comes on or
flashes. If a light comes on or flashes, bu t then goes off, this does not necessar-
ily indicate a malfunction in the system. However, if this continues to occur,
have the vehicle inspected by your Lexus dealer.
Warning light and warning buzzer list Warning light Warning light/Details/Actions(U.S.A.)
(Canada)
Brake system warning light
Indicates that:
• The brake fluid level is low; or
• The brake system is malfunctioning
Immediately stop the vehicle in a safe place and contact your
Lexus dealer. Continuing to drive the vehicle may be dangerous.
Brake system warning light
Indicates a malfunction in:
• The regenerative braking system;
• The electronically controlled brake system; or
• The electric parking brake
Have the vehicle inspected by your Lexus dealer immediately. (If equipped)
Charging system warning light
Indicates a malfunction in the vehicle’s charging system
Immediately stop the vehicle in a safe place and contact your
Lexus dealer. Continuing to drive the vehicle may be dangerous. (U.S.A.)
(Canada)
Malfunction indicator lamp
Indicates a malfunction in:
• The hybrid system;
• The electronic engine control system; or
• The electronic throttle control system
Have the vehicle inspected by your Lexus dealer immediately.
SRS warning light
Indicates a malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system
Have the vehicle inspected by your Lexus dealer immediately.

544 7-2. 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. 5 74 )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
light Wa r n i n g b u z z e r
* Wa r n i n g

546 7-2. 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 acceler ator 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 accelerator 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 for approximately one week after a new
electronic key has been registered.
If this message is displayed but you have 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 (if equipped) ●
AFS (Adaptive Front-lighting System) (if equipped)

5477-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U ■
If “Forward Camera System Unavailable” or “Forward Camera System
Unavailable Clean Windshield ” is displayed (if equipped)
The following systems may be suspended until the problem shown in the mes-
sage is resolved. ●
PCS (Pre-Collision System) ●
LKA (Lane-Keeping Assist) ●
LDA (Lane Departure Alert with steering control) ●
Dynamic radar cruise control with full-speed range ●
Dynamic radar cruise control ●
Automatic High Beam■
If “Oil Maintenance Required Soon” is shown
Indicates that the engine oil is schedule d to be changed. (The indicator will not
work properly unless the message has been reset.)
Check the engine oil, and change if ne cessary. After changing the engine oil,
the message should be reset. ( P. 4 7 8 )■
If “Oil Maintenance Required” is shown
Indicates that the engine oil should be changed. (After the engine oil is
changed and the message has been reset.)
Check and change the engine oil, and o il filter by your Lexus dealer. After
changing the engine oil, the message should be reset. ( P. 4 7 8 )■
If “Maintenance Required Soon” is displayed (U.S.A. only)
Indicates that all maintenance according to the driven distance on the mainte-
nance schedule
* should be performed soon.
Comes on approximately 4500 miles (7200 km) after the message has been
reset.
If necessary, perform maintenance. Pl ease reset the message after the main-
tenance is performed. ( P. 466)
* : Refer to the separate “Scheduled Mainte nance” or “Owner’s Manual Supplement”
for the maintenance interval applicable to your vehicle.

5597-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U WA R N I N G ■
When using the compact spare tire ●
Remember that the compact spare tire provid ed is specifically designed for use with
your vehicle. Do not use your compact spare tire on another vehicle. ●
Do not use more than one compact spare tire simultaneously. ●
Replace the compact spare tire with a standard tire as soon as possible.●
Avoid sudden acceleration, ab rupt steering, sudden bra king and shifting operations
that cause sudden engine braking. ■
When the compact spare tire is attached
The vehicle speed may not be correctly detected, and the following systems may not
operate correctly:
Also, not only can the following system not be utilized fully, but it may even negatively
affect the drive-train components:
•E-Four (AWD models) ■
Speed limit when using the compact spare tire
Do not drive at speeds in excess of 50 mph (80 km/h) when a compact spare tire is
installed on the vehicle.
The compact spare tire is not designed for driving at high speeds. Failure to observe
this precaution may lead to an accid ent causing death or serious injury.■
After using the tools and jack
Before driving, make sure all the tools and jack are securely in place in their storage
location to reduce the possibility of personal injury during a collision or sudden brak-
ing.• ABS & Brake assist
•VSC
•TRAC
•EPS
• Trailer Sway Control
•VDIM
• Adaptive Variable Suspension System
(if equipped)
• Cruise control (if equipped)
• Dynamic radar cruise control (if
equipped)
• Dynamic radar cruise control with full-
speed range (if equipped)
• PCS (Pre-Collision System) (if
equipped) • LDA (Lane Departure Alert with
steering control) (if equipped)
• LKA (Lane-Keeping Assist) (if
equipped)
• Automatic High Beam (if equipped)
• AFS (Adaptive Front-lighting System)
(if equipped)
• Tire pressure warning system
• Intuitive parking assist
• Lexus parking assist monitor (if
equipped)
• Panoramic view monitor (if equipped)
• BSM (Blind Spot Monitor)
• Navigation system

5697-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U Remove the engine cover.
Connect the jumper cables according 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 the negative cable to a solid, station-
ary, unpainted metallic point away from the exclusive jump starting terminal
and any moving parts, as shown in the illustration. 4
5
1
2
3
4

570 7-2. Steps to take in an emergency
RX450h_U_OM0E013U Start the engine of the second vehicle. Increase the engine speed slightly and
maintain at that level for approximately 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 second vehicle and start the hybrid system
of your vehicle by turning the 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 terminal 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 will discharge gradually even when the vehicle
is not in use, due to natural discharge and th e 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 unlock 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 return to the mode it was in before the 12-volt battery was
discharged. Before disconnecting 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. 1 5 0 )6
7
8
9
10
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