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4-3. Do-it-yourself maintenance
RX400h_U
CAUTION
The engine compartment contains many mechanisms and fluids that may move sud-
denly, become hot, or become electrically energized. To avoid death or serious injury:
■When working on the engine compartment
●Keep hands, clothing, and tools away from the moving fan and engine drive belt.
●Be careful not to touch the engine, inverter, radiator, exhaust manifold, etc. right
after driving as they may be hot. Oil and other fluids may also be hot.
●Do not leave anything that may burn easily, such as paper or rags, in the engine
compartment.
●Do not smoke, cause sparks or expose an open flame to fuel or the battery. Fuel
and battery fumes are flammable.
●Be extremely cautious when working on the battery. It contains poisonous and
corrosive sulfuric acid.
●Never touch, disassemble, remove or replace the high voltage parts, cables and
their connectors. It can cause severe burns or electric shock that may result in
death or serious injury.
●When the hybrid system is operating with the READY light on, the engine may
suddenly start in some cases. When you inspect the engine compartment, be
sure to turn off the hybrid system.
■When working near the electric cooling fan or radiator grille
Be sure the engine switch is off.
With the engine switch on, the electric cooling fan may automatically start to run if
the air conditioning is on and/or the coolant temperature is high. (→P. 3 2 5 )
■Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc. from getting
in the eyes.
NOTICE
■If you remove the air cleaner:
Driving with the air filter removed may cause excessive engine wear due to dirt in
the air. Also a backfire could cause a fire in the engine compartment.
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4-3. Do-it-yourself maintenance
RX400h_U
●Connect the equipment into an outlet on a circuit different from that to which the
receiver is connected.
●Consult the dealer or an experienced radio/TV technician for help.
FCC WARNING:
Changes or modifications not expressly approved by the party responsible for
compliance could void the user's authority to operate the equipment. For vehicles sold in Canada
Operation is subject to the following two conditions: (1) this device may not cause
interference, and (2) this device must accept any interference, including interfer-
ence that may cause undesired operation of the device.
CAUTION
■When inspecting or replacing tires
Observe the following precautions to prevent accidents.
Failure to do so may cause damage to parts of the drive train, as well as dangerous
handling characteristics, which may lead to fatal or injury accidents.
●Do not mix tires of different makes, models, tread patterns or treadwear.
●Do not use tire sizes other than those recommended by Lexus.
●Do not mix radial, bias-belted, or bias-ply tires.
●Do not mix summer, all season and winter tires.
■When initializing the tire pressure warning system
Do not push the tire pressure warning reset switch without first adjusting the tire
inflation pressure to the specified level. Otherwise, the tire pressure warning light
may not come on even if the tire inflation pressure is low, or it may come on when
the tire inflation pressure is actually normal.
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4-3. Do-it-yourself maintenance
4
Maintenance and care
RX400h_U
65HEATER7. 5
Electric cooling fan, air conditioning
system, rear window defogger, engine
switch, windshield wiper de-icer
66WA S H E R20Windshield washer
67SEAT HTR20No circuit
68GAUGE NO.17. 5
Instrument cluster lights, instrument
panel lights, emergency flashers, seat
belt, power outlet, multiport fuel injec-
tion system/sequential multiport fuel
injection system, back-up lights
69FR WIP30Windshield wipers
70RR WIP15Rear window wiper
71INJ 20
Multiport fuel injection system/
sequential multiport fuel injection sys-
tem
72IGN10
SRS airbag system, multiport fuel
injection system/sequential multiport
fuel injection system, front passenger
occupant classification system, stop
lights, hybrid vehicle immobilizer sys-
tem
73GAUGE NO.27. 5Gauge and meters
74ECU-ACC7. 5
Navigation system display, power rear
view mirror control, shift lock control
system, multiplex communication sys-
tem
75CIG15Po w e r o u t l e t
76PWR OUTLET
NO.115Po w e r o u t l e t
FuseAmpereCircuit
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5-1. Essential information
RX400h_U
Event data recorder
In a crash or a near car crash eventThe SRS airbag sensor assembly contains the EDR. In a crash or a near
car crash event, this device may record some or all of the following infor-
mation:
● Gasoline engine speed
● Whether the brake pedal was applied or not
● Ve h i c l e s p e e d
● To what extent the accelerator pedal was depressed
● Position of the transmission shift lever
● Whether the driver and front passenger wore seat belts or not
● Driver's seat position
● SRS airbag deployment data
● SRS airbag system diagnostic data
● Front passenger’s occupant classification
The information above is intended to be used for the purpose of improv-
ing vehicle safety performance. Unlike general data recorders, the EDR
does not record sound data such as conversation between passengers.
Your vehicle has computers that monitor and control certain aspects of
your vehicle. These computers assist in driving and maintaining optimal
vehicle performance.
Besides storing data useful for troubleshooting, there is an event data
recorder (EDR) that records data in a crash or a near car crash event.
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When trouble arises
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5-2. Steps to take in an emergency
RX400h_U
Stop the vehicle immediately.The following warnings indicate the possibility of damage to the vehicle
that may lead to an accident. Immediately stop the vehicle in a safe place
and contact your Lexus dealer.
Have the vehicle inspected by yo ur Lexus dealer immediately.
Failing to investigate the cause of the following warnings may lead to the
system operating abnormally and possibly cause an accident. Have the
vehicle inspected by your Lexus dealer immediately.
Warning lightWarning light/Details
Charging system warning light Indicates a malfunction in the vehicle’s charging system.
Warning lightWarning light/Details
(U.S.A.)
(Canada)
Malfunction indicator lampIndicates a malfunction in:
• The electronic engine control system or
• The electronic throttle control system.
Hybrid battery warning lightIndicates a malfunction in the vehicle’s hybrid battery.
SRS warning light
Indicates a malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system.
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When trouble arises
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5-2. Steps to take in an emergency
RX400h_U
Follow the correction procedures.After taking the specified steps to co rrect the suspected problem, check
that the warning light turns off.
Warning lightWarning light/DetailsCorrection procedure
Open door warning light
(warning buzzer)
Indicates that one or more of
the doors is not fully closed.
Close the indicated doors.
Low fuel level warning lightRemaining fuel
(Approximately 2.6 gal.
[9.8L, 2.2 Imp.gal.] or less)
Refuel the vehicle.
Driver’s seat belt reminder
light (warning buzzer)*1
Warns the driver to fasten
his/her seat belt.Fasten the seat belt.
Front passenger’s seat belt
reminder light (warning
buzzer)*
2
Warns the front passenger to
fasten his/her seat belt.
Fasten the seat belt.
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5-2. Steps to take in an emergency
RX400h_U
*1:Driver’s seat belt reminder:The driver’s seat belt reminder sounds to alert the driver that his or her seat belt
is not fastened. Once the engine switch is turned to the ON or START position,
the buzzer sounds for 4 to 8 seconds. If the vehicle has reached a speed of at
least 12 mph (20 km/h), the buzzer sounds intermittently for 10 seconds. Then,
if the seat belt is still unfastened, the buzzer will sound in a different tone for 20
more seconds.
*
2: Front passenger’s seat belt reminder:
The front passenger’s seat belt reminder sounds to alert the front passenger that
his or her seat belt is not fastened. The buzzer sounds intermittently for 10 sec-
onds after the vehicle has reached a speed of at least 12 mph (20 km/h). Then, if
the seat belt is still unfastened, the buzzer will sound in a different tone for 20
more seconds.
Warning lightWarning light/DetailsCorrection procedure
Tire pressure warning light
When the light comes on:
Low tire inflation pressure.Adjust the tire inflation pres-
sure.
When the light comes on after
blinking for 1 minute:
Malfunction in the tire pres-
sure warning system
Have the system inspected by
your Lexus dealer.
Master warning light A buzzer sounds and the
warning light comes on and
flashes to indicate that the
master warning system has
detected a malfunction.
Take appropriate action in
accordance with the message
displayed on the multi-infor-
mation display.
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When trouble arises
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5-2. Steps to take in an emergency
RX400h_U
■Key reminder buzzer
The buzzer indicates that the key has not been removed from the engine switch
(with the engine switch in the ACC or LOCK position and the driver’s door
opened).
■If the malfunction indicator lamp comes on while driving
First check the following:
●Is your vehicle low on gas?
If it is, refuel the vehicle immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The lamp will go off after taking several driving trips.
If the light does not go off even after several trips, contact your Lexus dealer as soon
as possible.
■Front passenger detection sensor and passenger seat belt reminder
●If luggage is placed on the front passenger seat, the front passenger detection
sensor may cause the warning light to flash, even if a passenger is not sitting in the
seat.
●If a cushion is placed on the seat, the sensor may not detect a passenger, and the
warning light may not operate properly.
■Changing the engine oil (U.S.A. only)
Make sure to reset the oil change system. ( →P. 3 2 1 )
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level. Pushing the tire
pressure warning reset switch does not turn off the tire pressure warning light.
■The tire pressure warning light may turn on due to natural causes
The tire pressure warning light may turn on due to natural causes such as natural air
leaks or 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).