air condition LEXUS RX400H 2008 Owner's Manual

312
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.

339
4-3. Do-it-yourself maintenance
4
Maintenance and care
RX400h_U
NOTICE
■Repairing or replacing tires, wheels and tire pressure warning valves and trans-
mitter
When removing or fitting the wheels, tires or the tire pressure warning valve and
transmitter, contact your Lexus dealer as the tire pressure warning valve and trans-
mitter may be damaged if not handled correctly.
■To avoid damaging the tire pressu re warning valves and transmitters
Do not use liquid sealants on flat tires.
■Driving on rough roads
Take particular care when driving on roads with loose surfaces or potholes.
These conditions may cause losses in tire inflation pressure, reducing the cushion-
ing ability of the tires. In addition driving on rough roads may cause damage to the
tires themselves, as well as the vehicle’s wheels and body.
■If tire inflation pressures become low while driving
Do not continue driving, or your tires and/or wheels may be ruined.

343
4-3. Do-it-yourself maintenance
4
Maintenance and care
RX400h_U
CAUTION
■Proper inflation is critical to save tire performance
Keep your tires properly inflated.
Otherwise, the following conditions may occur and result in an accident causing
death or serious injury.
●Excessive wear
●Uneven wear
●Poor handling
●Possibility of blowouts resulting from overheated tires
●Poor sealing of the tire bead
●Wheel deformation and/or tire separation
●A greater possibility of tire damage from road hazards
NOTICE
■When inspecting and adjusting tire inflation pressure
Be sure to reinstall the tire valve caps.
Without the valve caps, dirt or moisture could get into the valve and cause air leak-
age, which could result in an accident. If the caps have been lost, replace them as
soon as possible.

346
4-3. Do-it-yourself maintenance
RX400h_U
Air conditioning filter
The air conditioning filter must be changed regularly to maintain air condi-
tioning efficiency.
Turn the engine switch to the LOCK position.
Open the glove box.
Remove the 2 pins installed on
the upper part of the glove box
and lower the glove box.
Remove the filter case.
Remove the air conditioning fil-
ter from the filter case and
replace it with a new one.
The ↑UP marks shown on the
filter and the filter case should
be pointing up.
STEP1
STEP2
STEP3
STEP4

347
4-3. Do-it-yourself maintenance
4
Maintenance and care
RX400h_U
■Changing interval
Inspect and replace the air conditioning filter according to the maintenance sched-
ule. In dusty areas or areas with heavy traffic flow, early replacement may be
required. (For scheduled maintenance information, please refer to the “Warranty
and Service Guide”, “Owner's Manual Supplement” or “Scheduled Maintenance”.)
■If air flow from the vents decreases dramatically
The filter may be clogged. Check the filter and replace if necessary.
NOTICE
■When using the air conditioning system
Make sure that a filter is always installed.
Using the air conditioning system without a filter may cause damage to the system.

356
4-3. Do-it-yourself maintenance
RX400h_U■
Engine compartment (type B)
FuseAmpereCircuit
11HEATER50Air conditioning system, “WATER
PUMP” fuse
12IG130“SEAT HTR” fuse
13H-LP CLN30Headlight cleaner
14RR DEF40Rear window defogger
15RDI FAN No.140Electric cooling fan
16DC/DC120Hybrid system
17DRL7. 5Daytime running light system
18H-LP L LWR15Left-hand headlight (low beam)
19H-LP L UPR15Left-hand headlight
20H-LP R UPR15Right-hand headlight (high beam)
21PER OUTLET
NO.220Po w e r o u t l e t ( 1 1 5 VAC )
22TOW I N G30Trailer lights
23PBD30Power back door

357
4-3. Do-it-yourself maintenance
4
Maintenance and care
RX400h_U
24RDI FAN NO.240Electric cooling fan
25HAZ15Turn signal lights, emergency flashers
26MPX-B17. 5Electric power steering system
27AM2 NO.130“GAUGE NO.2”, “IGN”, “INJ” and
“ST” fuses
28HORN10Horns
29MAIN40
“H-LP L LWR”, “H-LP L UPR”, “H-LP
R LWR”, “H-LP R UPR” and “DRL”
fuses
30IGCT NO.150
“INV W/P”, “IGCT NO.2”, “IGCT
NO.3”, “IGCT NO.4” and “IGCT
NO.5” fuses
31RADIO NO.115Audio system
32ECU-B NO.17. 5
Theft deterrent system, air condition-
ing system, gauges and meters, moon
roof, multiplex communication system
33DOME7. 5
Personal lights, interior lights, vanity
lights, engine switch light, gauges and
meters, navigation system
34ECU-B NO.27. 5Wireless remote control
35AMP30Audio system
36DOOR NO.1 25Power door lock system
37A/F25Air/fuel control system
38CRT7. 5Navigation system screen, rear seat
entertainment system
39H-LP R LWR15Right-hand headlight (low beam)
40INV W/P15Hybrid system
FuseAmpereCircuit

358
4-3. Do-it-yourself maintenance
RX400h_U■
Engine compartment (type C)
41IGCT NO.510Hybrid system
FuseAmpereCircuit
42WAT E R P U M P10Air conditioning system
43SEAT HTR20Seat heaters
44IGCT NO.2 10Hybrid system
45IGCT NO.310Hybrid system, fuel pump
46IGCT NO.410Emission control system, transaxle
control system, air/fuel control system
FuseAmpereCircuit

361
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

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