ECU LEXUS LS500H 2019 Repair Manual

4317-2. Steps to take in an emergency
LS500h_OM_(U)_1809
7
When trouble arises
■Parking brake indicator (warning buzzer)
■Brake hold operated indicator (warning buzzer)
■Master warning light (warning buzzer)
■Warning buzzer
In some cases, the bu zzer may not be heard
due to being in a noisy location or audio
sound.
■Front passenger detection sensor, seat
belt reminder and warning buzzer
●If luggage is placed on the front passen-
ger seat, the front passenger detection
sensor may cause th e warning light to
flash and the warning buzzer to sound
even if a passenger is not sitting in the
seat.
●If a cushion is placed on the seat, the sen-
sor may not detect a passenger, and the
warning light may not operate properly.
■SRS warning light
This warning light system monitors the air- bag sensor assembly, Pop Up Hood com-
puter assembly, front impact sensors, side
impact sensors (front door), side impact
sensors (front), side
impact sensors (rear),
driver’s seat position sensor, driver’s seat
belt buckle switch, front passenger occu-
pant classification system (ECU and sen-
sors), rear seat belt buckle switches (if
equipped), “AIR BAG ON” indicator light,
“AIR BAG OFF” indicator light, front pas-
senger’s seat belt buckle switch, seat belt
pretensioners, airbags, interconnecting wir-
ing and power sources. ( P.29)
■If the malfunction indicator lamp comes
on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fuel tank immediately.
●Is the fuel tank cap loose?
Warning lightDetails/Actions
(flashes) (U.S.A.)
or
(flashes)
(Canada)
Indicates a malfunction in the parking brake system
 Have the vehicle inspected by your Lexus dealer immediately.
Warning lightDetails/Actions
(flashes)
Indicates a malfunction in the brake hold system
Have the vehicle inspected by your Lexus dealer immediately.
Warning lightDetails/Actions
A buzzer sounds and the warning light comes on and flashes to indicate
that the master warning system has detected a malfunction.
P.434

4327-2. Steps to take in an emergency
LS500h_OM_(U)_1809If it is, tighten it securely.
The light will go off after several driving
trips.
If the light does not go off even after several
trips, contact your Lexus dealer as soon as
possible.
■Electric power steering system warning
light (warning buzzer)
When the 12-volt battery charge becomes
insufficient or the voltage temporarily
drops, the electric po wer steering system
warning light may come on and the warning
buzzer may sound.
■When the tire pressure warning light
comes on
Inspect the tires to check if a tire is punc-
tured.
If a tire is punctured: P.439
If none of the tires are punctured:
Turn the power switch off then turn it to ON
mode. Check if the tire pressure warning
light comes on or blinks.
If the tire pressure wa rning light blinks for
approximately 1 minute then stays on
There may be a malfunction in the tire
pressure warning syst em. Have the vehicle
inspected by your Lexus dealer immedi-
ately.
If the tire pressure warning light comes
on
1 After the temperature of the tires has
lowered sufficiently, check the inflation
pressure of each tire and adjust them to
the specified level.
2 If the warning light does not turn off
even after several minutes have
elapsed, check that the inflation pres-
sure of each tire is at the specified level
and perform initialization. ( P.398)
■The tire pressure warning light may
come on due to natural causes
The tire pressure wa rning light may come
on due to natural causes such as natural air
leaks and tire inflation pressure changes
caused by temperature. In this case, adjust-
ing the tire inflation pressure will turn off the
warning light (after a few minutes).
■Conditions that the tire pressure warn-
ing system may not function properly
 P.395
WARNING
■If both the ABS and the brake system
warning lights remain on
Stop your vehicle in a safe place immedi-
ately and contact your Lexus dealer.
The vehicle will become extremely
unstable during br aking, and the ABS
system may fail, which could cause an
accident resulting in death or serious
injury.
■When the electric power steering
system warning light comes on
When the light comes on yellow, the
assist to the power st eering is restricted.
When the light comes on red, the assist
to the power steering is lost and handling
operations of the steering wheel become
extremely heavy.
When steering wheel operations are
heavier than usual, grip the steering
wheel firmly and operate it using more
force than usual.
■If the tire pressure warning light
comes on
Be sure to observe the following precau-
tions.
Failure to do so could cause a loss of
vehicle control and result in death or
serious injury.
●Decelerate to the lowest appropriate
speed as soon as possible. Do not
drive over 50 mph (80 km/h).
●Check and adjust the tire inflation
pressure immediately.
●If the tire pressure warning light comes
on even after tire inflation pressure
adjustment, it is prob able that you have
a flat tire. Have the flat tire replaced by
the nearest Lexus dealer.

4487-2. Steps to take in an emergency
LS500h_OM_(U)_1809
●Turn off any unnecessary electrical com-
ponents when the vehicle is running at a
low speed for an extended period, such
as in heavy traffic.
■When the 12-volt battery is removed or
discharged
●Information stored in the ECU is cleared.
When the 12-volt battery is depleted,
have the vehicle inspected at your Lexus
dealer.
●Some systems may require initialization.
( P.494)
■When removing the 12-volt battery ter-
minals
When the 12-volt battery terminals are
removed, the information stored in the
ECU is cleared. Before removing the
12-volt battery terminals, contact your
Lexus dealer.
■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 dis-
charge and the draining effects of certain
electrical appliances. If the vehicle is left for
a long time, the 12-volt battery may dis-
charge, and the hybrid system may be
unable to start. (The 12-volt battery
recharges automatically while the hybrid
system is operating.)
■When recharging or replacing the
12-volt battery
●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 mechani-
cal 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
discharged, be especially careful when
reconnecting the 12-volt battery.
■When replacing the 12-volt battery
●Use a Central Degassing type 12-volt
battery (European Regulations).
●Use a 12-volt battery with the same case
size as the previous 12-volt battery and an
equivalent 20 hour rate capacity (20HR)
or greater.
• If the sizes differ, the 12-volt battery can- not be properly secured.
• If the 20 hour rate capacity is low, even if
the time period where the vehicle is not
used is a short time, the 12-volt battery
may discharge and the hybrid system
may not be able to start.
●Use a 12-volt battery with a handle. If a
12-volt battery without a handle is used,
removal is more difficult.
●After replacing, firm ly attach the follow-
ing items to the exhaust hole of the
12-volt battery.
• Use the exhaust hose that was attached to the 12-volt battery before replacing
and confirm that it is firmly connected to
the hole section of the vehicle.
• Use the exhaust hole plug included with the 12-volt battery re placed or the one
installed on the 12-volt battery prior to
the replacement. (Depending on the
12-volt battery to be replaced, the
exhaust hole may be plugged.)

4497-2. Steps to take in an emergency
LS500h_OM_(U)_1809
7
When trouble arises
Exhaust hole plug
Exhaust hole
Exhaust hose
For details, consult your Lexus dealer.
WARNING
■When removing the 12-volt battery
terminals
Always remove the negative (-) terminal
first. If the positive (+) terminal contacts
any metal in the surrounding area when
the positive (+) terminal is removed, a
spark may occur, leading to a fire in addi-
tion to electrical shocks and death or
serious injury.
■Avoiding 12-volt battery fires or
explosions
Observe the following precautions to
prevent accidentally igniting the flamma-
ble gas that may be emitted from the
12-volt battery:
●Make sure each jumper cable is con-
nected to the correct terminal and that
it is not unintentiona lly in contact with
any other than the intended terminal.
●Do not allow the other end of the
jumper cable connected to the “+” ter-
minal to come into contact with any
other parts or metal surfaces in the
area, such as brackets or unpainted
metal.
●Do not allow the + and - clamps of the
jumper cables to come into contact
with each other.
●Do not smoke, use matches, cigarette
lighters or allow open flame near the
12-volt battery.
■12-volt battery precautions
The 12-volt battery contains poisonous
and corrosive acidic electrolyte, while
related parts contain lead and lead com-
pounds. Observe the following precau-
tions when handling the 12-volt battery:
A
B
C
●When working with the 12-volt battery,
always wear safety glasses and take
care not to allow any battery fluids
(acid) to come into contact with skin,
clothing or the vehicle body.
●Do not lean over the 12-volt battery.
●In the event that battery fluid comes
into contact with the skin or eyes,
immediately wash the affected area
with water and seek medical attention.
Place a wet sponge or cloth over the
affected area until medical attention
can be received.
●Always wash your ha nds after handling
the 12-volt battery support, terminals,
and other battery-related parts.
●Do not allow children near the 12-volt
battery.
■After recharging the 12-volt battery
Have the 12-volt battery inspected at
your Lexus dealer as soon as possible.
If the 12-volt battery is deteriorating, con-
tinued use may cause the 12-volt battery
to emit a malodorous gas, which may be
detrimental to the health of passengers.
■When replacing the 12-volt battery
●When the vent plug and indicator are
close to the hold down clamp, the bat-
tery fluid (sulfuric acid) may leak.
●For information regarding 12-volt bat-
tery replacement, contact your Lexus
dealer.
●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) ma y leak into the
vehicle interior, and there is the possi-
ble danger of the gas igniting and
exploding.

4788-1. Specifications
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*: Table 1 -Occupant loading and distribution for vehicle normal load for various desig-nated seating capacities
Treadwear indicators (TWI)
The projections within the principal grooves
designed to give a visual indication of the degrees
of wear of the tread
Wheel-holding fixtureThe fixture used to hold the wheel and tire assembly
securely during testing
Tire related termMeaning
Designated seating capac- ity, Number of occupantsVehicle normal load, Num- ber of occupantsOccupant distribution in a normally loaded vehicle
2 through 422 in front
5 through 1032 in front, 1 in second seat
11 through 1552 in front, 1 in second seat, 1 in third seat, 1 in fourth seat
16 through 2072 in front, 2 in second seat, 2 in third seat, 1 in fourth seat

4838-2. Customization
LS500h_OM_(U)_1809
8
Vehicle specifications
■Smart access system with push-button start and wireless remote control
(  P.112, 123)
■Smart access system with push-button start ( P.112, 123)
■Wireless remote control ( P.110, 112, 116)
FunctionDefault settingCustomized set-
ting
Operating signal (Buzzers)5OffO——O1 to 7
Operation signal (Emer-
gency flashers)OnOffO——O
Time elapsed before auto-
matic door lock function is
activated if door is not
opened after being unlocked
60 seconds
Off
O——O30 seconds
120 seconds
Open door warning buzzerOnOff———O
FunctionDefault settingCustomized set-ting
Smart access system with
push-button startOnOff———O
Smart door unlockingDriver’s doorAll the doorsO——O
Time elapsed before unlock-
ing all the door when gripping
and holding the driver’s door
handle
2 seconds
Off
———O1.5 seconds
2.5 seconds
Number of consecutive door
lock operations2 timesAs many as desired———O
FunctionDefault settingCustomized set- ting
Wireless remote controlOnOff———O
Unlocking operation
Driver’s door
unlocked in one step, all doors
unlocked in two step
All doors
unlocked in one step
O——O
ABCD
ABCD
ABCD

4969-1. For owners
LS500h_OM_(U)_1809
9-1.For owners
Déroulez la sangle diagonale de
telle sorte qu'elle passe bien sur
l'épaule, sans pour autant être en
contact avec le cou ou glisser de
l'épaule.
 Placez la sangle abdominale le plus
bas possible sur les hanches.
 Réglez la position du dossier de
siège. Asseyez-vous le dos droit et
calez-vous bien dans le siège.
 Ne vrillez pas la ceinture de sécu-
rité.
Reporting safety defects for
U.S. owners
If you believe that your vehicle has a
defect which could cause a crash or
could cause injury or death, you
should immediately inform the
National Highway Traffic Safety
Administration (NHTSA) in addition
to notifying the Lexus Division of
Toyota Motor Sales, U.S.A., Inc.
(Toll-free: 1-800-25-LEXUS).
If NHTSA receives similar com-
plaints, it may open an investigation,
and if it finds that a safety defect
exists in a group of vehicles, it may
order a recall and remedy campaign.
However, NHTSA cannot become
involved in individual problems
between you, your dealer, or Lexus
Division of Toyota Motor Sales,
U.S.A., Inc.
To contact NHTSA, you may call the
Vehicle Safety Hotline toll-free at
1-888-327-4236 (TTY:
1-800-424-9153); go to
http://www.safercar.gov ; or write to:
Administrator, NHTSA, 1200 New
Jersey Ave, S.E., Washington, DC
20590. You can also obtain other
information about motor vehicle
safety from
http://www.safercar.gov.
Seat belt instructions for
Canadian owners (in French)
The following is a French explana-
tion of seat belt instructions
extracted from the seat belt section
in this manual.
See the seat belt section for more
detailed seat belt instructions in
English.
Utilisation correcte des cein-
tures de sécurité

4979-1. For owners
LS500h_OM_(U)_1809
9
For owners
■Traitement des ceintures de sécu-
rité
Nettoyez avec un chiffon ou une
éponge humidifiés avec de l'eau savon-
neuse tiède. Vérifiez régulièrement
que les ceintures ne sont pas usées,
effilochées ou entaillées excessive-
ment.
Entretien et soin
ATTENTION
■Détérioration et usure des ceintures
de sécurité
Inspectez le système de ceintures de
sécurité régulière ment. Contrôlez
l'absence de coupures, d'effilochages et
de pièces desserrées. N'utilisez pas une
ceinture de sécurité endommagée avant
qu'elle ne soit remplacée. Une ceinture
de sécurité endommagée ne permet pas
de protéger un occupant de blessures
graves ou mortelles.

4999-1. For owners
LS500h_OM_(U)_1809
9
For owners
Coussins gonflables rideaux SRS
• Participent principalement à la protection de la tête des occupants des sièges latéraux
• Peut contribuer à empêcher les occupants d’être éjectés du véhicule en cas de tonneau
Coussins gonflables de coussin de siège SRS (sur modèles équip\
és)
Contribue à retenir les occupants des sièges arrière électriques
■Composants du système de coussins gonflables SRS
Système de classification de l'occupant du siège passager avant (ECU et cap-
teurs)
Capteurs d'impact latéral (porte avant)
Coussins gonflables de genoux
Coussin gonflable passager avant
Coussins gonflables rideaux
Témoins indicateurs “AIR BAG ON” et “AIR BAG OFF”
Coussins gonflables latéraux avant
Capteurs d'impact latéral (avant)
Témoin d'avertissement SRS
Coussins gonflables latéraux arrière
Prétensionneurs de ceinture de sécurité
Coussin gonflable conducteur
Coussins gonflables de coussin de siège (sur modèles équipé\
s)
Contacts de boucle de ceinture de sécurité de siège arrière \
(sur modèles
équipés)
E
F
A
B
C
D
E
F
G
H
I
J
K
L
M
N

5009-1. For owners
LS500h_OM_(U)_1809
Capteurs d'impact latéral (arrière)
Capteur de position du siège conducteur
Contact de boucle de ceinture de sécurité conducteur
Ensemble de capteurs de coussins gonflables
Capteurs d'impact avant
Ensemble informatique du capot actif
Votre véhicule est équipé de CO USSINS GONFLABLES INTELLIGENTS
conçus selon les normes de sécurité américaines applicables aux véhicules à
moteur (FMVSS208). L'ensemble de cap teurs de coussins gonflables (ECU)
régule le déploiement des coussins gonfla bles sur la base des informations qu'il
reçoit des capteurs, etc., indiqués ci-dessus dans le schéma illustrant les com-
posants du système. Parmi ces informations figurent la gravité du choc et l'occupa-
tion du véhicule par les passagers. Le déploiement rapide des coussins gonflables
est obtenu au moyen d'une réaction chimique dans les dispositifs pyrotechniques,
qui produit un gaz inoffensif permettant d'amortir le mouvement des occupants.O
P
Q
R
S
T
ATTENTION
■Précautions relatives aux coussins
gonflables SRS
Respectez les précautions suivantes
concernant les coussins gonflables SRS.
Le non-respect de ces précautions peut
occasionner des blessures graves, voire
mortelles.
●Le conducteur et tous les passagers du
véhicule doivent porter correctement
leur ceinture de sécurité.
Les coussins gonflables SRS sont des
dispositifs supplémentaires à utiliser
avec les ceinture s de sécurité.
●Le coussin gonflable conducteur SRS
se déploie avec une force con-
sidérable, pouvant occasionner des
blessures graves, voire mortelles, si le
conducteur se trouve très près du
coussin gonflable.
L'autorité fédérale ch argée de la sécurité
routière aux États-Unis (NHTSA) con-
seille: La zone à risque du coussin gon-
flable conducteur se situant dans les
premiers 2 à 3 in. (50 à 75 mm) de
déploiement, vous placer à 10 in. (250
mm) de votre coussin gonflable conduc-
teur vous garantit une marge de sécurité
suffisante. Cette distance est à mesurer
entre le centre du vola nt et le sternum. Si
vous êtes assis à moins de 10 in. (250
mm), vous pouvez changer votre posi-
tion de conduite de plusieurs façons:
• Reculez votre siège le plus possible, de manière à pouvoir encore atteindre
confortablement les pédales.