stop start LEXUS RX450h 2021 Workshop Manual

409
7
7
When trouble arises
When trouble arises
.7-1. Essential informationEmergency flashers................... 410
If your vehicle has to be stopped in an emergency ........................... 410
If the vehicle is trapped in rising water.............................................. 411
7-2. Steps to take in an emergency If your vehicle needs to be towed......................................................... 413
If you think something is wrong ......................................................... 417
If a warning light turns on or a warning buzzer sounds ........ 418
If a warning message is displayed ........................................................ 428
If you have a flat tire.................. 432
If the hybrid system will not start ........................................................ 444
If you lose your keys ................. 446
If the fuel filler door cannot be opened........................................ 446
If the electronic key does not operate properly .................... 447
If the 12-volt battery is discharged ........................................................ 449
If your vehicle overheats ........ 454
If the vehicle becomes stuck ........................................................ 457

4277-2. Steps to take in an emergency
7
When trouble arises
WARNING
■If a blowout or sudden air leakage
should occur
The tire pressure warning system may
not activate immediately.
■Maintenance of the tires
Each tire, including the spare (if pro-
vided), should be checked monthly when
cold and inflated to the inflation pressure
recommended by the vehicle manufac-
turer on the vehicle placard or tire infla-
tion pressure label (tire and load
information label). (I f your vehicle has
tires of a different size than the size indi-
cated on the vehicle placard or tire infla-
tion pressure label [tire and load
information label], yo u should determine
the proper tire infl ation pressure for
those tires.)
As an added safety feature, your vehicle
has been equipped with a tire pressure
monitoring system (TPMS-tire pressure
warning system) that illuminates a low
tire pressure telltale (tire pressure warn-
ing light) when one or more of your tires
is significantly under-inflated. Accord-
ingly, when the low tire pressure telltale
(tire pressure warnin g light) illuminates,
you should stop and check your tires as
soon as possible, and inflate them to the
proper pressure. Driving on a signifi-
cantly under-inflated tire causes the tire
to overheat and can lead to tire failure.
Under-inflation also reduces fuel effi-
ciency and tire tread life, and may affect
the vehicle’s handling and stopping abil-
ity.
Please note that the TPMS (tire pressure
warning system) is not a substitute for
proper tire maintenance, and it is the
driver’s responsibility to maintain correct
tire pressure, even if under-inflation has
not reached the level to trigger illumina-
tion of the TPMS low tire pressure telltale
(tire pressure warning light).
Your vehicle has also been equipped with
a TPMS (tire pressure warning system)
malfunction indicator to indicate when
the system is not operating properly. The
TPMS (tire pressure warning system)
malfunction indicator is combined with
the low tire pressure telltale (tire pres-
sure warning light) . When the system
detects a malfunction, the telltale will
flash for approximately one minute and
then remain continuously illuminated.
This sequence will continue upon subse-
quent vehicle start-ups as long as the
malfunction exists. When the malfunction
indicator is illuminated, the system may
not be able to detect or signal low tire
pressure as intended.
TPMS (tire pressure warning system)
malfunctions 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 func-
tioning 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
pressure warning system) to continue to
function properly.
NOTICE
■To ensure the tire pressure warning
system operates properly
Do not install tires with different specifi-
cations or makers, as the tire pressure
warning system may not operate prop-
erly.

4307-2. Steps to take in an emergency
not be charged when the shift lever is in N,
shift the shift lever to P when the vehicle is
stopped.
■If “Traction Battery Needs to be Pro-
tected. Shift into P to Restart.” is dis-
played
This message is displayed when the hybrid
battery (traction battery) charge has
become extremely low because the shift
lever has been left in N for a certain amount
of time.
When operating the vehicle, shift to P and
restart the hybrid system.
■If “Shift Is in N Release Accelerator
Before Shifting” is displayed
Message is displayed when the accelerator
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 Syst em May Overheat”
is displayed
Message is displayed when the accelerator
pedal is depressed to maintain the vehicle
position when stopped on a upward slope,
etc.
If this continues, th e 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
started, increase the engine speed slightly
and maintain it at that speed for approxi-
mately 5 minutes to recharge the 12-volt
battery.
■If “Headlight System Malfunction Visit
Your Dealer” is displayed
The following systems may be malfunction-
ing. Have the vehicle inspected by your
Lexus dealer immediately.
●The LED headlight system
●AFS (Adaptive Front-lighting System) (if equipped)
●The automatic headlight leveling system
●Automatic High Beam
■If “Radar Cruise Control Unavailable
See Owner's Manual” is displayed
The dynamic radar cruise control with
full-speed range system is suspended tem-
porarily or until the problem shown in the
message is re solved. (causes and coping
methods: P.218)
■If “Radar Cruise Control Unavailable” is
displayed
The dynamic radar cruise control with
full-speed range system cannot be used
temporarily. Use the system when it
becomes available again.
■If a message that indicates the malfunc-
tion of front camera is displayed
The following systems may be suspended
until the problem shown in the message is
resolved. ( P.218, 424)
●PCS (Pre-Collision system)
●LTA (Lane Tracing Assist)
●Automatic High Beam
●RSA (Road Sign Assist) (if equipped)
●Dynamic radar cruise control with
full-speed range
■If “Maintenance Required Soon” is dis-
played (U.S.A. only)
Indicates that all maintenance according to
the driven distance on the maintenance
schedule
* should be performed soon.
Comes on approximately 4500 miles
(7200 km) after the message has been
reset. If necessary, perform maintenance.
Please reset the message after the mainte-
nance is performed. ( P.362)
*: Refer to the separate “Scheduled Main-
tenance” or “Owner’s Manual Supple-
ment” for the main tenance interval
applicable to your vehicle.
■If “Maintenance Required Visit Your
Dealer” is displayed (U.S.A. only)
Indicates that all mainte nance is required to
correspond to the driven distance on the

4497-2. Steps to take in an emergency
7
When trouble arises
When the smart access system with
push-button start is deactivated in custom-
ization setting, the powe r switch will turn to
ACCESSORY mode.
3 Firmly depress the brake pedal and
check that is shown on the
multi-information display.
4 Press the power switch shortly and
firmly.
In the event that the hybrid system still
cannot be started, contact your Lexus
dealer.
■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 sys-
tem.
■Replacing the key battery
As the above procedure is a temporary
measure, it is recomme nded that the elec-
tronic key battery be replaced immediately
when the battery is depleted. ( P.393)
■Alarm (For Canada)
Using the mechanical key to lock the doors
will not set the alarm system.
If a door is unlocked using the mechanical
key when the alarm system is set, the alarm
may be triggered. ( P.75)
■Changing power switch modes
Release the brake pedal and press the
power switch in step 3 above. The hybrid
system does not start and modes will be
changed each time the switch is pressed.
(  P.187)
If the 12-volt battery is dis-
charged
The following procedures may be
used to start the hybrid system if the
vehicle’s 12-volt battery is dis-
charged.
You can also call your Lexus dealer
or a qualified repair shop.

4547-2. Steps to take in an emergency
“Engine Coolant Temp High Stop in
a Safe Place See Owner’s Manual”
is shown on the multi-information
display
1 Stop the vehicle in a safe place and
turn off the air conditioning system,
and then stop the hybrid system.
2 If you see steam:
Carefully lift the hood after the
steam subsides.
If you do not see steam:
Carefully lift the hood.
3 After the hybrid system has cooled
down sufficiently, inspect the hoses
WARNING
●Make sure to replace the 12-volt bat-
tery with one designed for this vehicle.
Otherwise, 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 (hydrogen) may leak into the
vehicle interior, and there is the possi-
ble danger of the gas igniting and
exploding.
NOTICE
■When handling jumper cables
When connecting the jumper cables,
ensure that they do not become entan-
gled in the cooling fans or belt.
■To prevent damaging the vehicle
The exclusive jump starting terminal is to
be used when charging the 12-volt bat-
tery from another ve hicle in an emer-
gency. It cannot be used to jump start
another vehicle.
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
 The needle of the engine coolant
temperature gauge ( P.83)
enters the red zone, or a loss of
hybrid system power is experi-
enced. (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 Output power
reduced” is shown on the
multi-information display.
 Steam comes out from under the
hood.
Correction procedures

4557-2. Steps to take in an emergency
7
When trouble arises
and radiator core (radiator) for any
leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4The coolant level is satisfactory if it
is between the “FULL” and “LOW”
lines on the reservoir.
Reservoir
“FULL” line
“LOW” line
Radiator cap
5 Add coolant if necessary.
Water can be used in an emergency if coolant is unavailable.
6
Start the hybrid system and turn the
air conditioning system on to check
that the radiator cooling fans oper-
ate and to check for coolant leaks
from the radiator or hoses.
The fans operate when the air conditioning
system is turned on immediately after a
cold start. Confirm that the fans are oper-
ating by checking the fan sound and air
flow. If it is difficult to check these, turn the
air conditioning system on and off repeat-
edly.
(The fans may not oper ate in freezing tem-
peratures.)
7 If the fans are not operating:
Stop the hybrid system immediately
and contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the
nearest Lexus dealer.
8 Check if “Engine Coolant Temp
High Stop in a Safe Place See
Owner's Manual” is shown on the
multi-information display.
If the message does not disappear:
Stop the hybrid system and contact your
Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the nearest
A
B
A
B
C
D

4567-2. Steps to take in an emergency
Lexus dealer.
If “Hybrid System Overheated Out-
put power reduced” is shown on the
multi-information display
1 Stop the vehicle in a safe place.
2 Stop the hybrid system and care-
fully lift the hood.
3 After the hybrid system has cooled
down, inspect the hoses and radia-
tor core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4The coolant level is satisfactory if it
is between the “FULL” and “LOW”
lines on the reservoir.
Reservoir
“FULL” line
“LOW” line 5
Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
6Start the hybrid system and check if
“Hybrid System Overheated Out-
put power reduced” is shown on
the multi-information display.
If the message does not disappear:
Stop the hybrid system and contact
your Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the
nearest Lexus dealer.
A
B
A
B
C
WARNING
■When inspecting under the hood of
your vehicle
Observe the following precautions.
Failure to do so may result in serious
injury such as burns.
●If steam is seen coming from under the
hood, do not open the hood until the
steam has subsided. The engine com-
partment may be very hot.

4577-2. Steps to take in an emergency
7
When trouble arises
1Stop the hybrid system. Shift the
shift lever to P and set the parking
brake.
2 Remove the mud, snow or sand
from around the front wheels.
3 Place wood, stones or some other
material under the front wheels to
help provide traction.
4 Restart the hybrid system.
5 Shift the shift lever to D or R and
release the parking brake. Then,
while exercising caution, depress
the accelerator pedal.
■When it is difficult to free the vehicle
Press to turn off TRAC.
WARNING
●After the hybrid system has been
turned off, check that the “READY”
indicator is off.
When the hybrid system is operating,
the gasoline engine may automatically
start, or the cooling fans may suddenly
operate even if the gasoline engine
stops. Do not touch or approach rotat-
ing parts such as the fans, which may
lead to fingers or cl othing (especially a
tie, a scarf or a muffler) getting caught,
resulting in serious injury.
●Do not loosen the radiator cap and the
coolant reservoir caps while the hybrid
system and radiator are hot.
High temperature steam or coolant
could spray out.
NOTICE
■When adding engine/power control
unit coolant
Add coolant slowly after the hybrid sys-
tem has cooled down sufficiently. Adding
cool coolant to a hot hybrid system too
quickly can cause damage to the hybrid
system.
■To prevent damage to the cooling sys-
tem
Observe the following precautions:
●Avoid contaminating the coolant with
foreign matter (such as sand or dust,
etc.).
●Do not use any coolant additive.
If the vehicle becomes stuck
Carry out the following proce-
dures if the tires spin or the vehicle
becomes stuck in mud, dirt or snow:
Recovering procedure

511What to do if... (Troubleshooting)
If you cannot release the shift lever by
depressing the brake pedal with the power
switch in ON mode (P.192)
It is locked automatically to prevent
theft of the vehicle. ( P.185)
 Is the window lock switch pressed?
The power window except for the one at
the driver’s seat cannot be operated if the
window lock switch is pressed. ( P.155)
 The auto power off function will be
operated if the vehicle is left in
ACCESSORY or ON mode (the
hybrid system is not operating) for a
period of time. ( P.187)
 The seat belt reminder light is flash-
ing
Are the driver and the passengers wearing
the seat belts? ( P.421)
 The parking brake indicator is on
Is the parking brake released? ( P.195)
Depending on the situation, other
types of warning buzzer may also
sound. ( P.418, 428) 
Did anyone inside the vehicle open
a door during setting the alarm?
The sensor detects it and the alarm sounds.
( P.75)
Do one of the following to stop the
alarms:
 Unlock the doors.
 Turn the power switch to ACCES-
SORY or ON mode, or start the
hybrid system.
 Is the message displayed on the
multi-information display?
Check the message on the multi-informa-
tion display. ( P.428)
 When a warning light turns on or a
warning message is displayed, refer
to P.418, 428.
 Stop the vehicle in a safe place and
replace the flat tire with the spare
tire. ( P.432)
The steering wheel cannot be
turned after the hybrid system is
stopped
The windows do not open or
close by operating the power
window switches
The power switch is turned off
automatically
A warning buzzer sounds during
driving
An alarm is activated and the
horn sounds
A warning buzzer sounds when
leaving the vehicle
A warning light turns on or a
warning message is displayed
When a problem has occurred
If you have a flat tire

516Alphabetical Index
If the electronic key does not operate properly....................................................... 447
If the fuel filler door cannot be opened ......................................................................... 446
If the hybrid system will not start ........ 444
If the vehicle is trapped in rising water411
If you have a flat tire .................................. 432
If you lose your keys................................. 446
If you think something is wrong ........... 417
If your vehicle becomes stuck............. 457
If your vehicle has to be stopped in an
emergency ................................................. 410
If your vehicle needs to be towed ....... 413
If your vehicle overheats ........................ 454
Energy monitor ..................................... 99, 100
Engine ACCESSORY mode ...............................187
Compartment ............................................... 371
Engine switch................................................ 184
Hood................................................................369
How to start the hybrid system ........... 184
Identification number .................................461
If the hybrid system will not start ........ 444
If your vehicle has to be stopped in an
emergency ................................................. 410
Ignition switch (power switch) ............. 184
Overheating................................................. 454
Power switch ................................................ 184
Tachometer ..................................................... 83
Engine coolant Capacity ......................................................... 464
Checking ....................................................... 373
Preparing and checking before winter........................................................................... 291
Engine coolant temperature gauge ....... 83
Engine oil Capacity ......................................................... 463
Checking ......................................................... 371
Preparing and checking before winter........................................................................... 291
Warning light .................................................419
Engine oil maintenance data .................. 373 Engine switch (power switch) ................. 184
If your vehicle has to be stopped in an emergency .................................................. 410
EPS (Electric Power Steering) .............. 284 Warning light .................................................421
EV drive mode............................................... 189
EV indicator .......................................................67
Event data recorder (E DR) ........................... 8
F
Flat tire
Tire pressure warning system .............382
Vehicles with a spare tire....................... 432
Floor mats .......................................................... 24
Fluid Brake ............................................................... 465
Hybrid transmission................................. 465
Washer ...........................................................375
Fog lights Switch.............................................................. 206
Footwell light ...................................................321
Front automatic air conditioning system .......................................................................... 304
Front fog lights Replacing light bulbs ............................... 400
Front passenger footwell hooks ............ 345
Front passenger occupant classification system .............................................................. 39
Front seats Adjustment ....................................................... 131
Cleaning ........................................................ 359
Correct driving posture ............................ 25
Driving position memory .........................142
Head restraints............................................. 145
Memory recall function.............................143
Power easy access system .....................142
Seat heaters ................................................... 318
Seat position memory ...............................142
Seat ventilators ............................................. 318
Front side marker light Light switch .................................................. 200
Replacing light bulbs ............................... 400