2018 LEXUS RX450h ECU

731-2. Child safety
1
For safety and security
RX450h_RX450hL _U_OM48F85UWARNING ■
When installing a child restraint system
Observe the following precautions.
Failure to do so may result in death or serious injury.●
Firmly attach the top tether strap and make sure that the belt is not twisted. ●
Do not attach the top strap to anything other than the anchor bracket of the seat the
child restraint system is installed to. ●
Follow all installation instructions provided by the child restraint system manufacturer.●
When installing the child restraint system with the head restraint being raised, after
the head restraint has been raised and then the anchor bracket has been fixed, do not
lower the head restraint. ●
When installing a child restraint system in th e rear center seat, adjust both seat cush-
ions to the same position an d align both seatbacks at th e same angle. The seatbacks
must be adjusted to the same angle. Othe rwise, the child restra int system cannot be
securely restrained and this may cause death or serious injuries in the event of sudden
braking, sudden swerving or an accident. ●
If the seat is adjusted, reconfirm the security of the child restraint system.
NOTICE ■
Anchor brackets (for top tether strap)
When not in use, make certain to close the lid. If it remains open, the lid may be dam-
aged.

751-3. Hybrid system
1
For safety and security
RX450h_RX450hL _U_OM48F85U◆ When stopped/during start off
The gasoline engine stops* when the vehi cle is stopped. During start off, the
electric motor (traction mo tor) drives the vehicle. At slow speeds or when
traveling down a gentle slope, the engi ne is stopped* and the electric motor
(traction motor) is used.
When the shift lever is in N, the hybrid battery (traction battery) is not being
charged.
* : When the hybrid battery (traction battery) requires charging or the engine is warm-
ing up, etc., the gasoline engine will not automatically stop. ( → P. 76)
◆ During normal driving
The gasoline engine is predominantly used. The electric motor (traction
motor) charges the hybrid battery (traction battery) as necessary.
◆ When accelerating sharply
When the accelerator pedal is depressed heavily, the power of the hybrid bat-
tery (traction battery) is added to that of the gasoline engine via the electric
motor (traction motor).
◆ When braking (regenerative braking)
The wheels operate the electric motor (traction motor) as a power generator,
and the hybrid battery (traction battery) is charged.
When the gasoline engine is off while driving, a sound is produced to warn
pedestrians, people riding bicycles or other people and vehicles in the surround-
ing area that the vehicle is approaching. The pitch of the sound varies according
to the vehicle speed. When the vehicl e speed becomes approximately 15 mph
(25 km/h) or more, the notification sound turns off.Vehicle proximity notification system

771-3. Hybrid system
1
For safety and security
RX450h_RX450hL _U_OM48F85U■
Sounds and vibrations specific to a hybrid vehicle
There may be no engine sound or vibration even though the vehicle is able to move with
the “READY” indicator is illuminate d. For safety, make sure to shift the shift lever to P and
apply the parking brake when parked.
The following sounds or vibrations may occu r when the hybrid system is operating and
are not a malfunction: ●
Motor sounds may be heard from the engine compartment. ●
Sounds may be heard from the hybrid battery (traction battery) be hind the rear seats
when the hybrid system starts or stops. ●
Relay operating sounds such as a snap or so ft clank will be emitted from the hybrid bat-
tery (traction battery), behind the rear se ats, when the hybrid system is started or
stopped. ●
Sounds from the hybrid system may be heard when the back door is open. ●
Sounds may be heard from the transmission wh en the gasoline engine starts or stops,
when driving at low spee ds, or during idling.●
Engine sounds may be heard when accelerating sharply. ●
Sounds may be heard due to regenerative braking when the brake pedal is depressed
or as the accelerator pedal is released. ●
Vibration may be felt when the ga soline engine starts or stops.●
Cooling fan sounds may be heard from th e air intake vents under the rear seats.■
Vehicle proximity notification system
In the following cases, the vehicle proximity notification system may be difficult for sur-
rounding people to hear. ●
In very noisy areas ●
In the wind or the rain
Also, as the vehicle proximity notification system is installed on the fr ont of the vehicle, it
may be more difficult to hear from the re ar of the vehicle compared to the front.■
Maintenance, repair, re cycling, and disposal
Contact your Lexus dealer regarding mainte nance, repair, recycling and disposal. Do
not dispose of the vehicle yourself. ■
Customization
Some functions can be customized. ( → P. 736)

791-3. Hybrid system
1
For safety and security
RX450h_RX450hL _U_OM48F85UThe air intake/discharge vents for the
hybrid battery (traction battery) are
located under the rear seats and in lug-
gage compartment respectively. If the
air intake vents are blocked, it could
lead to a reduction in hybrid battery
(traction battery) output.
* : RX450h
When a certain level of impact is detect ed by the impact sensor, the emergency
shut off system blocks the high voltage current and stops the fuel pump to mini-
mize the risk of electrocution and fuel leakage. If the emergency shut off system
activates, your vehicle will not restart. To restart the hybrid system, contact your
Lexus dealer.
A message is automatically displayed wh en a malfunction occurs in the hybrid
system or an improper operation is attempted.
If a warning message is shown on the
multi-information display, read the
message and follow the instructions.
( → P. 667)Hybrid battery (traction battery) air intake/discharge vents Air intake vents
Air discharge vents
*Emergency shut off system
Hybrid warning message

811-3. Hybrid system
1
For safety and security
RX450h_RX450hL _U_OM48F85UWARNING ■
Road accident cautions
Observe the following precautions to reduce the risk of death or serious injury:●
Pull your vehicle off the road, shift the shif t lever to P, apply the parking brake, and
turn the hybrid system off. ●
Do not touch the high voltage parts, cables and connectors. ●
If electric wires are exposed inside or ou tside your vehicle, an electric shock may
occur. Never touch exposed electric wires. ●
If a fluid leak occurs, do not touch the flui d as it may be strong alkaline electrolyte
from the hybrid battery (traction battery). If it comes into contact with your skin or
eyes, wash it off immediately with a large amount of water or, if possible, boric acid
solution. Seek immedi ate medical attention.●
If a fire occurs in the hybrid vehicle, leave the vehicle as soon as possible. Never use a
fire extinguisher that is not meant for el ectric fires. Using even a small amount of
water may be dangerous. ●
If your vehicle needs to be towed, do so wi th all four wheels rais ed. If the wheels con-
nected to the electric motor (traction motor) are on the ground when towing, the
motor may continue to generate elec tricity. This may cause a fire. ( → P. 654)●
Carefully inspect the ground under the vehicl e. If you find that liquid has leaked onto
the ground, the fuel system may have been damaged. Leave the vehicle as soon as
possible. ■
Hybrid battery (traction battery) ●
Never resell, hand over or modify the hybrid battery. To prevent accidents, hybrid
batteries that have been removed from a disposed vehicle are collected through
Lexus dealer. Do not dispose of the battery yourself.
Unless the battery is properly collected, th e following may occur, resulting in death
or serious injury:
• The hybrid battery may be illegally dispos ed of or dumped, and it is hazardous to
the environment or someone may touch a high voltage part, resulting in an electric
shock.
• The hybrid battery is intended to be used exclusively with your hybrid vehicle. If
the hybrid battery is used outside of your vehicle or modified in any way, accidents
such as electric shock, heat generation , smoke generation, an explosion and elec-
trolyte leakage may occur.
When reselling or handing over your vehicle, the possibility of an accident is
extremely high because the person receiving the vehicle may not be aware of these
dangers. ●
If your vehicle is disposed of without the hybrid battery having been removed, there is
a danger of serious electric shock if high voltage parts, cables and their connectors
are touched. In the event that your vehicle must be disposed of, the hybrid battery
must be disposed of by your Lexus dealer or a qualified service shop. If the hybrid bat-
tery is not disposed of properly, it may cause electric shock that can result in death or
serious injury.

83 1
For safety and security
RX450h_RX450hL _U_OM48F85U 1-4. Theft deterrent system
The indicator light flashes after the
power switch has been turned off to
indicate that the system is operating.
The indicator light stops flashing after
the power switch has been turned to
ACCESSORY or ON mode to indi-
cate that the system has been canceled. ■
System maintenance
The vehicle has a maintenance-fr ee type immobilizer system.■
Conditions that may cause the system to malfunction ●
If the grip portion of the key is in contact with a metallic object●
If the key is in close proximity to or touching a key registered to the security system (key
with a built-in transponder chip) of another vehicleImmobilizer system The vehicle’s keys have built-in transp onder chips that prevent the hybrid sys-
tem from starting if a key has not been previously registered in the vehicle’s
on-board computer.
Never leave the keys inside the vehicle when you leave the vehicle.
This system is designed to help preven t vehicle theft but does not guarantee
absolute security agai nst all vehicle thefts.

851-4. Theft deterrent system
1
For safety and security
RX450h_RX450hL _U_OM48F85U 
For vehicles sold in Canada
WARNING ■
Certifications for the immobilizer system
Changes or modifications not expressly appr oved by the party responsible for compli-
ance could void the user’s authority to operate the equipment.
NOTICE ■
To ensure the system operates correctly
Do not modify or remove the system. If mo dified or removed, the proper operation of
the system cannot be guaranteed.

871-4. Theft deterrent system
1
For safety and security
RX450h_RX450hL _U_OM48F85U■
System maintenance
The vehicle has a maintenance-free type alarm system. ■
Items to check before locking the vehicle
To prevent unexpected triggering of the alarm and vehicle theft, make sure of the follow-
ing: ●
Nobody is in the vehicle. ●
The windows and moon roof or panoramic mo on roof are closed before the alarm is
set. ●
No valuables or other personal items are left in the vehicle.■
Triggering of the alarm
The alarm may be triggered in the following situations:
(Stopping the alarm deactivates the alarm system.)
■
Alarm-operated door lock
In the following cases, depending on the si tuation, the door may automatically lock to
prevent improper entry into the vehicle: ●
When a person remaining in the vehicle un locks the door and the alarm is activated.●
While the alarm is activated, a person re maining in the vehicl e unlocks the door.●
When recharging or replacing the 12-volt battery ●
A person inside the vehicle opens a door or
hood, or unlocks the vehicle.
●
The 12-volt battery is recharged or replaced
when the vehicle is locked. ( → P. 698)
NOTICE ■
To ensure the system operates correctly
Do not modify or remove the system. If mo dified or removed, the proper operation of
the system cannot be guaranteed.