stop start LEXUS RX450H 2019 Service Manual

3824-5. Using the driving support systems
RX450h_RX450hL_U
◆ECB (Electronically Controlled Brake System)
The electronically controlled system generates braking force corresponding
to the brake operation
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the br akes are applied suddenly, or if the
brakes are applied while drivin g on a slippery road surface
◆Brake assist
Generates an increased level of br aking force after the brake pedal is
depressed when the system detects a panic stop situation
◆VSC (Vehicle Stability Control)
Helps the driver to contro l skidding when swerving suddenly or turning on
slippery road surfaces.
◆Enhanced VSC (Enhanced Vehicle Stability Control)
Provides cooperative control of the ABS, TRAC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery road sur-
faces by controlling steering performance.
◆Trailer Sway Control (if equipped)
Helps the driver to control trailer sway by selectively applying brake pressure
for individual wheels and reducing dr iving torque when trailer sway is
detected.
◆TRAC (Traction Control)
Helps to maintain drive power and pr event the drive wheels from spinning
when starting the vehicle or accelerating on slippery roads
◆Hill-start assist control
Helps to reduce the backward movement of the vehicle when starting on an
uphill
Driving assist systems
To keep driving safety and performance, the following systems operate auto-
matically in response to various drivin g situations. Be aware, however, that
these systems are supplementary and shou ld not be relied upon too heavily
when operating the vehicle.

3854-5. Using the driving support systems
4
Driving
RX450h_RX450hL_U
■Turning off both TRAC VSC and Trailer Sway Control systems
To turn the TRAC VSC and Trailer Sway Co ntrol systems off, press and hold for
more than 3 seconds whil e the vehicle is stopped.
The VSC OFF indicator light will come on an d the “Traction Control Turned Off” will be
shown on the multi-information display.
*
Press again to turn the systems back on.
*: On vehicles with PCS (Pre-Collision Sy stem), pre-collision brake assist and pre-
collision braking will also be disabled. The PCS warning light will come on and a
message will be displa yed on the multi-information display. (P. 296)
■When the message is displayed on the mu lti-information display showing that TRAC
has been disabled even if has not been pressed
TRAC cannot be operated. Contact your Lexus dealer.
■Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will operate:
●The shift lever is in a position other than P or N (when starting off forward/backward on
an upward incline).
●The vehicle is stopped
●The accelerator pedal is not depressed
●The parking brake is not engaged
■Automatic system cancelation of hill-start assist control
The hill-start assist control will turn off in any of the following situations:
●The shift lever is shifted to P or N
●The accelerator pedal is depressed
●The parking brake is engaged
●2 seconds at maximum elapsed after the brake pedal is released
■Sounds and vibrations caused by the ABS, brake assist, VSC, Trailer Sway Control,
TRAC and hill-start assist control systems
●A sound may be heard from the engine compartment when the brake pedal is
depressed repeatedly, when the hybrid system is started or just after the vehicle begins
to move. This sound does not indicate that a malfunction has occurred in any of these
systems.
●Any of the following conditions may occur when the above systems are operating.
None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard also after the vehicle comes to a stop.

3894-6. Driving tips
4
Driving
RX450h_RX450hL_U
◆Delays
Repeated acceleration and deceleration, as well as long waits at traffic lights,
will lead to bad fuel economy. Check traffic reports before leaving and avoid
delays as much as possible. When drivin g in a traffic jam, gently release the
brake pedal to allow the vehicle to move forward slightly while avoiding over-
use of the accelerator pedal. Doing so can help control excessive gasoline
consumption.
◆Highway driving
Control and maintain the vehicle at a co nstant speed. Before stopping at a toll
booth or similar, allow plenty of ti me to release the accelerator and gently
apply the brakes. A greater amount of electrical energy can be regenerated
when slowing down.
◆Air conditioning
Use the air conditioning only when necessary. Doing so can help reduce
excessive gasoline consumption.
In summer: When the ambient temperature is high, use the recirculated air
mode. Doing so will help to reduce the burden on the air conditioning system
and reduce fuel consumption as well.
In winter: Because the gasoline engine will not automatically cut out until it
and the interior of the vehicle are warm , it will consume fuel. Also, fuel con-
sumption can be improved by av oiding overuse of the heater.
◆Checking tire inflation pressure
Make sure to check the tire inflation pr essure frequently. Improper tire infla-
tion pressure can cause poor fuel economy.
Also, as snow tires can cause large amou nts of friction, their use on dry roads
can lead to poor fuel economy. Use tires that are appropriate for the season.
◆Luggage
Carrying heavy luggage will lead to poor fuel economy. Avoid carrying
unnecessary luggage. Installing a large roof rack will also cause poor fuel
economy.
◆Warming up before driving
Since the gasoline engine starts up an d cuts out automatically when cold,
warming up the engine is unnecessary. Moreover, frequently driving short dis-
tances will cause the engine to repeated ly warm up, which can lead to excess
fuel consumption.

4815-11. Bluetooth®
5
Lexus Display Audio system
RX450h_RX450hL_U
In other situations
Even though all conceivable measures have been taken, the symptom status does not
change.
The cellular phone is not close enough to this system.
 Bring the cellular phone closer to this system.
The cellular phone is the most likely cause of the symptom.
 Turn the cellular phone off, remove and reinstall the battery pack, and then
restart the cellular phone.
 Enable the cellular phone’s Bluetooth
® connection.
 Stop the cellular phone’s security software and close all applications.
 Before using an application installed on the cellular phone, carefully check its
source and how its operation might affect this system.

5186-2. Using the air conditioning system and defogger
RX450h_RX450hL_U
■Registering air conditioning settings to electronic keys
●Unlocking the vehicle using an electronic key and turning the power switch to ON
mode will recall that ke y’s registered air conditioning settings.
●When the power switch is turned off, the cu rrent air conditioning settings will automati-
cally be registered to the electronic key that was used to unlock the vehicle.
●The system may not operate correctly if more th an one electronic key is in the vicinity or
if the smart access system with push-button start is used to unlock a passenger door.
●The doors that can recall the air conditioning setting when unlocked using the smart
access system with push-button start can be changed.
* For details, contact your Lexus
dealer.
*: The doors that can recall the driving positi on memory are changed at the same time.
■Using automatic mode
Fan speed is adjusted automatically according to the temperature setting and the ambi-
ent conditions.
Therefore, the fan may stop for a while until wa rm or cool air is ready to flow immediately
after the “AUTO” button is pressed or “AUTO” is selected.
■How the system judges if a passenger is in the vehicle when in S-FLOW mode
In S-FLOW mode, the system judges if a passenger is in the vehicle as follows:
• Front passenger seat: A passeng er is judged to be in the front passenger seat when the
system detects an object on the front passenger seat, fastening of the front passenger
seat belt, changing of the set temperature for the front passenger seat or the opening
and closing of the front passenger door. (However, when only opening and closing of
the front passenger door is detected, the sy stem will judge that a passenger is not in
the front passenger seat after the vehicl e speed reaches approximately 12 mph (20
km/h) or more.)
• Rear seats (automatic S-FLOW mode only): A passenger is judged to be in a rear seat
when the system detects the opening and closin g of a rear door or the operation of the
rear air conditioning system (RX450hL).
If a passenger is judged to be in the vehicl e, the system will retain the judgement for a
certain amount of time after th e power switch is turned off.
■Operation of automatic S-FLOW mode
When the system is operating in automati c S-FLOW mode, if the system detects the
opening and closing of a rear door or the op eration of the rear air conditioning system
(RX450hL), S-FLOW mode will be disabled. To enable S-FLOW mode, select
on the option control screen. (In this case , the system will operate in manual S-FLOW
mode.)
■Changing from manual S-FLOW mode to automatic S-FLOW mode
Select on the option control screen to disable S-FLOW mode.
Turn the power switch off.
Wait for 60 minutes or more and change the power switch to ON mode.
■Using the voice command system
Air conditioning system can be operated using voice commands. For details, refer to the
“NAVIGATION SYSTEM OWNER’S MANUAL”.
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5496-5. Using the other interior features
6
Interior features
RX450h_RX450hL_U
■Name for all partsPower supply switch
Operation indicator light
Charge area
■Using the wireless chargerPress the power supply switch of
the wireless charger.
Pressing the switch again turns the
wireless charger off.
When turned on, the operation indi-
cator light (green) comes on.
When the power switch is turned off,
the on/off state of the wireless char-
ger will be memorized.
Place a portable device on the
charging area with its charging
surface facing down.
While charging, the operation indi-
cator light (orange) will be illumi-
nated.
If charging does not begin, move the
portable device as close to the cen-
ter of the charging area as possible.
When charging is complete, the operatio n indicator light (green) will illuminate.
●Recharging function
• If a certain amount of time has elapsed since charging completed and the portable device has not been moved, the wireless charger will
restart charging.
• If the portable device is moved with in the charging area, charging will
stop temporarily then restart.
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5636-5. Using the other interior features
6
Interior features
RX450h_RX450hL_U
■Enabling 2-way communication with a garage door (only available for com-
patible devices)
When enabled, 2-way communication allows you to check the status of the
opening and closing of a garage door through indicators in your vehicle.
2-way communication is only available if the garage door opener motor used
is a compatible device. (To check devi ce compatibility, refer to www.Home-
Link.com.)
Within 5 seconds after programming the garage door opener has been
completed, if the garage door op ener motor is trained to HomeLink
®,
both garage door operation indicator s will flash rapidly (green) and the
light on the garage door opener moto r will blink twice, indicating that 2-
way communication is enabled.
If the indicators do not flash, perform and within the first 10 presses of
the HomeLink
® button after programming has been completed.
Press a programmed HomeLink
® button to operate a garage door.
Within 1 minute of pressing the HomeLink
® button, after the garage door
operation has stopped, press the “Learn” or “Smart” button on the garage
door opener motor. Within 5 seconds of the establishment of 2-way com-
munication with the garage door opener, both garage door operation indi-
cators in the vehicle will flash rapidly (green) and the light on the garage
door opener motor will blink twice, indicating that 2-way communication is
enabled.
■Reprogramming a single HomeLink® button
When the following procedure is performed, buttons which already have
devices registered to them can be overwritten: With one hand, press and hold the desired HomeLink
® button.
When the HomeLink
® indicator starts flashing (orange), continue to hold
the HomeLink® button and perform “Programming HomeLink®” (it
takes 20 seconds for the HomeLink® indicator to start flashing).
Press the appropriate HomeLink
® button. The HomeLink® indicator light
should turn on.
Operating HomeLink®
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651
8When trouble arises
RX450h_RX450hL_U
8-1. Essential informationEmergency flashers .................. 652
If your vehicle has to be stopped in
an emergency .......................... 653
8-2. Steps to take in an emergency
If your vehicle needs to be towed................................ 654
If you think something is wrong ........................................... 659
If a warning light turns on or a warning buzzer
sounds..........................................660
If a warning message is displayed..................................... 667
If you have a flat tire .................. 673
If the hybrid system will
not start .......................................690
If the electronic key does not operate properly ............. 692
If the 12-volt battery is discharged ................................. 695
If your vehicle overheats ......... 702
If the vehicle becomes stuck ............................................. 706

6668-2. Steps to take in an emergency
RX450h_RX450hL_U
WARNING
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly when cold and
inflated to the inflation pressure recomm ended by the vehicle manufacturer on the
vehicle placard or tire inflation pressure label (tire and load information label). (If your
vehicle has tires of a different size than the size indicated on the vehicle placard or tire
inflation pressure label [tire and load in formation label], you should determine the
proper tire inflation pressure for those tires.)
As an added safety feature, your vehicle ha s been equipped with a tire pressure moni-
toring system (TPMS-tire pressure warning system) that illuminates a low tire pressure
telltale (tire pressure warning light) when on e or more of your tires is significantly
under-inflated. Accordingly, when the low ti re pressure telltale (tire pressure warning
light) illuminates, you should stop and check your tires as soon as possible, and inflate
them to the proper pressure. Driving on a si gnificantly under-inflated tire causes the
tire to overheat and can lead to tire failure . Under-inflation also reduces fuel efficiency
and tire tread life, and may affect the vehicle’s handling and stopping ability.
Please note that the TPMS (tire pressure wa rning system) is not a substitute for proper
tire maintenance, and it is th e driver’s responsibility to ma intain correct tire pressure,
even if under-inflation has not reached the le vel to trigger illumination of the TPMS low
tire pressure telltale (tir e pressure warning light).
Your vehicle has also been equipped with a TPMS (tire pressure warning system) mal-
function indicator to indicate when the system is not operating properly. The TPMS
(tire pressure warning system) malfunction indi cator is combined with the low tire pres-
sure telltale (tire pressure warning light). When the system detects a malfunction, the
telltale will flash for approximately one mi nute and then remain continuously illumi-
nated. This sequence will cont inue upon subsequent vehicle start-ups as long as the
malfunction exists. When the malfunction in dicator is illuminated, the system may not
be able to detect or signal low tire pressure as intended.
TPMS (tire pressure warning system) malfun ctions may occur for a variety of reasons,
including the installation of replacement or alternate tires or wheels on the vehicle that
prevent the TPMS (tire pressure warning system) from functioning properly. Always
check the TPMS (tire pressure warning system) malfunction telltale after replacing one
or more tires or wheels on your vehicle to ensure that the replacement or alternate
tires and wheels allow the TPMS (tire pressu re warning system) to continue to function
properly.
NOTICE
■To ensure the tire pressure warning system operates properly
Do not install tires with different specifications or makers, as the tire pressure warning
system may not operate properly.

6698-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL_U
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. 702
■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