2019 LEXUS RX450H lights

6608-2. Steps to take in an emergency
RX450h_RX450hL_U
If 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, but then goes off, this does not necessar-
ily indicate a malfunction in the system. However, if this continues to occur,
have the vehicle inspecte d by your Lexus dealer.
Warning light and warning buzzer list
Warning lightWarning 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.

6658-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL_U
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such as natural air
leaks and tire inflation pressure changes caus ed by temperature. In this case, adjusting
the tire inflation pressure will turn off the warning light (after a few minutes).
■When a tire is replaced with a spare tire
The compact spare tire is not equipped with a tire pressure warning valve and transmit-
ter. If a tire goes flat, the tire pressure warning light will not turn off even though the flat
tire has been replaced with the spare tire. Replace the spare tire with the repaired tire
and adjust the tire inflation pressure. The tire pressure warnin g light will go off after a few
minutes.
■Conditions that the tire pressure wa rning system may not function properly
 P. 616
■Warning buzzer
In some cases, the buzzer ma y not be heard due to being in a noisy location or audio
sound.
■Customization
Some functions can be customized. ( P. 736)
WARNING
■If both the ABS and the brake sy stem warning lights remain on
Stop your vehicle in a safe place immediat ely and contact your Lexus dealer. The vehi-
cle will become extremely unstable during br aking, and the ABS system may fail, which
could cause an accident resultin g 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 steering 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 precaution s. Failure to do so could cause a loss of
vehicle control and result in death or serious injury.
●Stop your vehicle in a safe place as soon as possible. Adjust the tire inflation pressure
immediately.
●If the tire pressure warning light comes on even after tire inflation pressure adjust-
ment, it is probable that you have a flat tire . Check the tires. If a tire is flat, change it
with the spare tire and have the flat tire repaired by the nearest Lexus dealer.
●Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you could lose
control of the steering wheel or the brakes.
■If a blowout or sudden air leakage should occur
The tire pressure warning system may not activate immediately.

6678-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL_U
The warning lights and warning buzzers operate as follows depending on the
content of the message. If a message indicates the need for inspection by a
dealer, have the vehicle inspected by your Lexus dealer immediately.
If a warning message is displayed
The multi-information display shows warn ings of system malfunctions, incor-
rectly performed operations, and messag es that indicate a need for mainte-
nance. When a message is shown, perform the correction procedure
appropriate to the message.
Except F SPORT modelsF SPORT models
Master warning light
The master warning light also comes on or flashes in order to indicate that a message
is currently being displayed on the multi-information display.
Multi-information display
If any of the warning messages are sh own again after the appropriate actions
have been performed, contact your Lexus dealer.
Messages and warnings
1
2
System
warning light
Warning buzzer*Warning
Comes on 
Sounds Indicates an important situation, such
as when a system related to driving is
malfunctioning or that danger may
result if the correction procedure is not
performed
Comes on
or flashesSounds
Indicates an important situation, such
as when the systems shown on the
multi-information display may be mal-
functioning

6728-2. Steps to take in an emergency
RX450h_RX450hL_U
■If “Maintenance Required Visit Your Dealer” is displayed (U.S.A. only)
Indicates that all maintenance is requir ed to correspond to the driven distance
on the maintenance schedule
*.
Comes on approximately 5000 miles (8000 km) after the message has
been reset.
(The indicator will not work properly unless the message has been reset.)
Perform the necessary maintenance. Please reset the message after the main-
tenance is performed. ( P. 588)
*: Refer to the separate “Scheduled Mainte nance” or “Owner’s Manual Supplement”
for the maintenance interval applicable to your vehicle.
■System warning lights
The master warning light does not come on or flash in the following cases. Instead, a sep-
arate system warning light will come on along with a message shown on the multi-infor-
mation display.
●“Braking Power Low Visit Your Dealer”:
The brake system warning light (yellow) come on. ( P. 660)
●“Antilock Brake System Malfunction Visit Your Dealer”:
The ABS warning light comes on. ( P. 661)
●“Charging System Malfunction See Ow ner's Manual” (F SPORT models):
The charging system wa rning light comes on. (P. 660)
■Warning buzzer
 P. 665
NOTICE
■“High Power Consumption Partial Limit On AC/Heater Operation” is frequently
shown
There is a possible malfunction relating to the charging system or the 12-volt battery
may be deteriorating. Have the vehicle inspected by your Lexus dealer.

6908-2. Steps to take in an emergency
RX450h_RX450hL_U
One of the following may be the cause of the problem:
●The electronic key may not be functioning properly. ( P. 692)
●There may not be sufficient fuel in the vehicle’s tank.
Refuel the vehicle.
●There may be a malfunction in the immobilizer system. ( P. 83)
●There may be a malfunction in the steering lock system.
●The hybrid system may be malfunctioni ng due to an electrical problem such
as electronic key battery depletion or a blown fuse. However, depending on
the type of malfunction, an interim meas ure is available to start the hybrid sys-
tem. ( P. 691)
One of the following may be the cause of the problem:
●The 12-volt battery may be discharged. ( P. 695)
●The 12-volt battery terminal connections may be loose or corroded.
( P. 691)
If the hybrid system will not start
Reasons for the hybrid system not star ting vary depending on the situation.
Check the following and perform the appropriate procedure:
The hybrid system will not start even though the correct starting proce-
dure is being followed. ( P. 239)
The interior lights and headlights are d im, or the horn does not sound or
sounds at a low volume.

6918-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL_U
One of the following may be the cause of the problem:
●The 12-volt battery may be discharged. (P. 695)
●One or both of the 12-volt battery terminals may be disconnected. ( P. 605)
Contact your Lexus dealer if the problem cannot be repaired, or if repair procedures
are unknown.
When the hybrid system does not start, the following steps can be used as an
interim measure to start the hybrid system if the power switch is functioning nor-
mally.
Do not use this starting procedur e except in cases of emergency.
Turn the power switch to ON mode an d check that the parking brake is set.
( P. 240, 253)
Shift the shift lever to P.
Turn the power switch to ACCESSORY mode.
Press and hold the power switch for ab out 15 seconds while depressing the
brake pedal firmly.
Even if the hybrid system can be starte d using the above steps, the system may
be malfunctioning. Have the vehicle inspected by your Lexus dealer.
The interior lights and headlights do not turn on, or the horn does not
sound.
Emergency start function
1
2
3
4

6978-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL_U
Start the engine of the second vehicle. Increase the engine speed slightly and
maintain at that level for approximatel y 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 seco nd vehicle and start the hybrid system
of your vehicle by turning th e 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 termin al 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.
■When removing the battery terminals
When the battery terminals are removed, the information stored in the ECU is cleared.
Before removing the battery termin als, contact your Lexus dealer.
6
7
8
9
10
11

7159-1. Specifications
9
Vehicle specifications
RX450h_RX450hL_U
*: The coolant capacity is a reference quantity. If replacement is necessary, contact your Lexus dealer.
Cooling system
Capacity*
Gasoline
engine
RX450h
10.7 qt. (10.1 L, 8.9 Imp. qt.)
RX450hL
13.2 qt. (12.5 L, 11 Imp. qt.)
Power control
unit2.0 qt. (1.9 L, 1.7 Imp. qt.)
Coolant type
Use either of the following: • “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-basednon-silicate, non-amine, non-nitrite, and non-
borate coolant with long-life hybrid organic
acid technology
Do not use plain water alone.
Ignition system (spark plug)
MakeDENSO FK20HBR8
Gap0.03 in. (0.8 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.
Electrical system
12-volt battery
Open voltage at 68F (20C):
12.6 V or higher: Fully charged
12.2 — 12.4 V: Half charged
12.0 V or lower: Discharged
(Voltage is checked 20 minutes after the hybrid
system and all lights are turned off.)
Charging rates5 A max.