2008 LEXUS RX400H engine

359
4-3. Do-it-yourself maintenance
4
Maintenance and care
RX400h_U■
Driver’s side instrument panel
FuseAmpereCircuit
47RR DOOR RH20Rear right side power window
48RR DOOR LH20Rear left side power window
49FUEL OPN7. 5Fuel filler door opener
50FR FOG15Front fog lights
51OBD7. 5On-board diagnosis system
52FR DEF25Windshield wiper de-icer and all com-
ponents in “MIR HTR” fuses
53STOP10
Tail lights, high mounted stoplight,
vehicle dynamics integrated manage-
ment, shift lock control system,
multiport fuel injection system/
sequential multiport fuel injection sys-
tem
54TI&TE30Tilt and telescopic steering
55MPX-B7. 5Engine immobilizer system
56AM1 7. 5Starter system

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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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4-3. Do-it-yourself maintenance
4
Maintenance and care
RX400h_U
Light bulbs
You may replace the following bulbs yourself. For more information about
replacing other light bulbs, contact your Lexus dealer.
■Prepare a replacement light bulb.
Check the wattage of the light bulb being replaced. ( →P. 441)
■ Remove the engine compartment cover.
→ P. 317
■ Turn the power back door main switch OFF.
→ P. 4 5
■ Front bulb locations
Parking light Front turn
signal light
Front side
marker light
Headlight
low beam
(halogen bulb)
Headlight
high beam
(halogen bulb)

5
When trouble arises
379
5-1. Essential information
RX400h_U
■Emergency towing procedureRelease the parking brake.
Shift the shift lever to N.
Turn the engine switch to the ACC (hybrid system off) or ON (hybrid sys-
tem on) position.
CAUTION
■Caution while towing
●Use extreme caution when towing the vehicle.
Avoid sudden starts or erratic driving maneuvers which place excessive stress on
the emergency towing eyelets and the cables or chains.
●If the hybrid system is not running, the power assist for the brakes and steering
will not function, making steering and braking more difficult.
NOTICE
■To prevent causing serious damage to the transmission
Never tow this vehicle from the rear with four wheels on the ground.
This may cause serious damage to the transmission.
STEP1
STEP2
STEP3

5
When trouble arises
385
5-1. Essential information
RX400h_U
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
■Visible symptoms
●Fluid leaks under the vehicle
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● Engine coolant temperature gauge needle continually points
higher than normal
■ Audible symptoms
●Changes in exhaust sound
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the hybrid system
■ Operational symptoms
●Engine missing, stumbling or running rough
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one side when driving on a level road
● Loss of brake effectiveness, sp ongy feeling, pedal almost touches
the floor

386
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.

5
When trouble arises
389
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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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.