Page 646 of 860
646
GS450h_U (OM30D01U)
6-3. Do-it-yourself maintenance
If any washer does not work or the
warning message appears on the
multi-information display, the
washer tank may be empty. Add
washer fluid.
Wa s h e r f l u i d
CAUTION
■When adding washer fluid
Do not add washer fluid when the hybrid system is hot or operating as washer fluid
contains alcohol and may catch fire if spilled on the engine etc.
NOTICE
■Do not use any fluid other than washer fluid
Do not use soapy water or engine antifreeze instead of washer fluid.
Doing so may cause streaking on the vehicle’s painted surfaces.
■Diluting washer fluid
Dilute washer fluid with water as necessary.
Refer to the freezing temperatures listed on the label of the washer fluid bottle.
Page 653 of 860

GS450h_U (OM30D01U)
6536-3. Do-it-yourself maintenance
6
Maintenance and care
Your vehicle is equipped with a tire pressure warning system that uses tire
pressure warning valves and transmitters to detect low tire inflation pres-
sure before serious problems arise.
Vehicles without the tire inflation pressure display function
If the tire pressure drops below a predetermined level, the driver is
warned by a warning light. ( P. 715)
Vehicles with the tire inflation pressure display function
●If the tire pressure drops below a predetermined level, the driver is
warned by a screen display and a warning light. ( P. 740)
●The tire pressure detected by the tire pressure warning system can be
displayed on the multi- information display. (P. 9 7 )
◆Installing tire pressure warning valves and transmitters
When replacing tires or wheels, tire pressure warning valves and trans-
mitters must also be installed.
When new tire pressure warning valves and transmitters are installed,
new ID codes must be registered in the tire pressure warning computer
and the tire pressure warning system must be initialized. Have tire pres-
sure warning valve and transmitter ID codes registered by your Lexus
dealer. ( P. 655)
◆Initializing the tire pressure warning system
■The tire pressure warning system must be initialized in the following
circumstances:
●When rotating the tires.
●When the tire inflation pressure is changed such as when changing
traveling speed or load weight.
When the tire pressure warning system is initialized, the current tire
inflation pressure is set as the benchmark pressure.
Tire pressure warning system
Page 655 of 860

GS450h_U (OM30D01U)
6556-3. Do-it-yourself maintenance
6
Maintenance and care
◆Registering ID codes
The tire pressure warning valve and transmitter is equipped with a
unique ID code. When replacing a tire pressure warning valve and
transmitter, it is necessary to register the ID code. Have the ID code
registered by your Lexus dealer.
■When to replace your vehicle’s tires
Tires should be replaced if:
●You have tire damage such as cuts, splits , cracks deep enough to expose the fabric,
and bulges indicating internal damage
●A tire goes flat repeatedly or cannot be properly repaired due to the size or loca-
tion of a cut or other damage
If you are not sure, consul t with your Lexus dealer.
■Replacing tires and wheels
If the ID code of the tire pressure warning valve and transmitter is not registered, the
tire pressure warning system will not work properly. After driving for about 20 min-
utes, the tire pressure warning light blinks for 1 minute and stays on to indicate a sys-
tem malfunction.
■Tire life
Any tire over 6 years old must be checked by a qualified technician even if it has sel-
dom or never been used or damage is not obvious.
■Routine tire inflation pressure checks
The tire pressure warning system does not replace routine tire inflation pressure
checks. Make sure to check tire inflation pressure as part of your routine of daily
vehicle checks.
■When rotating the tires (vehicles with the tire inflation pressure display function)
Make sure that the power switch is off. If the tires are rotated while the power switch
is in ON mode, the tire position information will not be updated.
If this accidentally occurs, either turn the power switch to off and then to ON mode,
or initialize the system after checking that the tire pressure is properly adjusted.
Page 657 of 860

GS450h_U (OM30D01U)
6576-3. Do-it-yourself maintenance
6
Maintenance and care
■If the tread on snow tires wears down below 0.16 in. (4 mm)
The effectiveness of the tires as snow tires is lost.
■Situations in which the tire pressure warning system may not operate properly
●In the following cases, the tire pressure warning system may not operate properly.
• If non-genuine Lexus wheels are used.
• A tire has been replaced with a tire that is not an OE (Original Equipment) tire.
• A tire has been replaced with a tire that is not of the specified size.
• Tire chains etc. are equipped.
• Lock nuts are equipped.
• An auxiliary-supported run- flat tire is equipped.
• If a window tint that affects the radio wave signals is installed.
• If there is a lot of snow or ice on the vehicle, particularly around the wheels or wheel housings.
• If the tire inflation pressure is extremely higher than the specified level.
●Performance may be affected in the following situations.
• Near a TV tower, electric power plant, gas station, radio station, large display,
airport or other facility that generates strong radio waves or electrical noise
• When carrying a portable radio, cellular phone, cordless phone or other wire- less communication device
Vehicles with the tire inflation pressure display function: If tire position information
is not correctly disp layed due to the radio wave conditions, the display may be
corrected by driving and changing the radio wave conditions.
●When the vehicle is parked, the time taken for the warning to start or go off could
be extended.
●When tire inflation pressure declines rapi dly for example when a tire has burst, the
warning may not function.
■The initialization operation
●Make sure to carry out initialization after adjusting the tire inflation pressure.
Also, make sure the tires are cold before carrying out initialization or tire inflation
pressure adjustment.
●If you have accidentally turned the power switch off during initialization, it is not
necessary to press the reset switch again as initialization will restart automatically
when the power switch has been turn ed to ON mode for the next time.
●If you accidentally press the reset switch when initialization is not necessary, adjust
the tire inflation pressure to the specified level when the tires are cold, and conduct
initialization again.
Page 659 of 860

GS450h_U (OM30D01U)
6596-3. Do-it-yourself maintenance
6
Maintenance and care
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 an accident resulting in death or seri-
ous injury.
●Do not mix tires of different makes, models or tread patterns.
Also, do not mix tires of remarkably different treadwear.
●Do not use tire sizes other than those recommended by Lexus.
●Do not mix differently constructed tires (r adial, bias-belted or bias-ply tires).
●Do not mix summer, all season and snow tires.
●Do not use tires that have been used on another vehicle.
Do not use tires if you do not know how they were used previously.
■When initializing the tire pressure warning system
Do not operate the tire pressure warning re set 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.
■Caution regarding interference with elec tronic devices (vehicles with the tire
inflation pressure display function)
●Users of any electrical medical device other than implanted pacemakers and
implanted cardiac defibrillators should consult the manufacturer of the device for
information about its operation under the influence of radio waves.
Radio waves could have unexpected effects on the operation of such medical
devices.
●People with implanted pacemakers or car-
diac defibrillators should not come within
17.7 in. (450 mm) of the tire pressure warn-
ing system initiators. The radio waves may
affect the operation of such devices.
Page 676 of 860

676
GS450h_U (OM30D01U)
6-3. Do-it-yourself maintenance
34DOME7. 5
Personal lights, ornament lights, trunk light,
footwell lights, door courtesy lights, vanity
lights, rear door inside handle illuminations,
power trunk opener and closer
35MPX-B10
Body ECU, smart access system with push-
button start, electric tilt and telescopic steer-
ing column, power seats, head-up display,
front door ECU, gauges and meters, steer-
ing sensor, yaw rate and G sensor, overhead
module, RR CTRL SW, power trunk opener
and closer, clock, CAN gateway ECU
36IGCT NO.410Po w e r c o n t r o l u n i t
37IGCT NO.37. 5Hybrid battery (traction battery), DC/DC
converter
38IGCT NO.25Hybrid system
39IG2 NO.15DCM, CAN gateway ECU
40GAUGE5Gauges and meters
41DC/DC150RH-J/B DC/DC, P/I DC/DC
42P/ I D C / D C100RR S/SHADE, DEFOG, FOG, TAIL,
PA N E L
43RH J/B DC/DC80Right-hand junction block
44LH J/B DC/DC50Left-hand junction block
45H-LP CLN30Headlight cleaner
46FAN NO.240Electric cooling fans
47LUG J/B DC/DC80Luggage compartment junction block
48FAN NO.180Electric cooling fans
49PTC NO.150PTC heater
50PTC NO.250PTC heater
51HTR50Air conditioning system
FuseAmpereCircuit
Page 678 of 860
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GS450h_U (OM30D01U)
6-3. Do-it-yourself maintenance
■Driver’s side instrument panel
FuseAmpereCircuit
1STOP7. 5Stop lights, high mounted stoplight
2P/ W- B5Po w e r w i n d o w m a s t e r s w i t c h
3P/ S E AT 1 F/ L30Po w e r s e a t s
4D/L NO.125Power door lock system
5NV-IR10Lexus night view
6FL S/HTR10Seat heaters/ventilators
7WIPER30Windshield wipers
8WIPER-IG5Windshield wipers
9LH-IG10
Seat belts, body ECU, AFS, overhead mod-
ule, raindrop sensor, inside rear view mirror,
lane camera sensor (LKA), head-up display,
shift lock system, intuitive parking assist, front
left-hand door ECU, driver monitor system,
Remote Touch screen, electric tilt and tele-
scopic steering column, power seats, moon
roof, windshield wiper de-icer, intuitive park-
ing assist switch, PTC heater, headlight
cleaner
10LH ECU-IG10
VDIM, ECB, D-SW MODULE (Blind Spot
Monitor, heated steering wheel), driver sup-
port system, AFS, EPB, air conditioning sys-
tem
Page 681 of 860
GS450h_U (OM30D01U)
6816-3. Do-it-yourself maintenance
6
Maintenance and care
14MULTIMEDIA10Navigation system, Remote Touch
15RAD NO.130Audio system
16AIR BAG10SRS airbag system, occupant classification
system
17OBD7. 5On-board diagnosis system
18ACC7. 5
Body ECU, head-up display, RR CTRL, navi-
gation system, hybrid transmission, Remote
Touch, DCM, Remote Touch screen, clock
FuseAmpereCircuit