Page 796 of 1014

7726-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30D53E_(EE)
Tire inflation pressure
Effects of incorrect tire inflation pressure
Driving with incorrect tire inflation pressure may result in the following:
Reduced fuel efficiency
Reduced driving comfort and tire life
Reduced safety
Damage to the drive train
If a tire needs frequent inflating, have it checked by any authorized Lexus
dealer or repairer, or another duly qualified and equipped professional.
Instructions for checking tire inflation pressure
When checking tire inflation pressure, observe the following:
Check only when the tires are cold.
If your vehicle has been parked for at least 3 hours or has not been driven
for more than 1.5 km or 1 mile, you will get an accurate cold tire inflation
pressure reading.
Always use a tire pressure gauge.
The appearance of the tire can be misleading. In addition, tire inflation pres-
sure that is even just a few pounds off can affect ride quality and handling.
Do not reduce tire inflation pressure after driving. It is normal for tire infla-
tion pressure to be higher after driving.
Never exceed the vehicle capacity weight.
Passengers and luggage weight should be placed so that the vehicle is bal-
anced.
Make sure to maintain proper tire inflation pressure. Tire inflation
pressure should be checked at least once per month. However,
Lexus recommends that tire inflation pressure be checked once
every two weeks. (P. 936)
Page 797 of 1014
773 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS450h_300h_OM_OM30D53E_(EE)
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 put the tire valve caps back on.
Without the valve caps, dirt or moisture could get into the valve and cause
air leakage, which could result in an accident. If the caps are lost, replace
them as soon as possible.
Page 799 of 1014

775
6 6-3. Do-it-yourself maintenance
Maintenance and care
GS450h_300h_OM_OM30D53E_(EE)
Use only Lexus wheel nuts and wrenches designed for use with
your aluminum wheels.
When rotating, repairing or changing your tires, check that the
wheel nuts are still tight after driving 1600 km (1000 miles).
Be careful not to damage the aluminum wheels when using tire
chains.
Use only Lexus genuine balance weights or equivalent and a
plastic or rubber hammer when balancing your wheels.
When replacing wheels (vehicles with the tire pressure warning system)
The wheels of your vehicle are equipped with tire pressure warning valves
and transmitters that allow the tire pressure warning system to provide
advance warning in the event of a loss in tire inflation pressure. Whenever
wheels are replaced, tire pressure warning valves and transmitters must be
installed. (P. 756)
Aluminum wheel precautions
CAUTION
When replacing wheels
Do not use wheels that are a different size from those recommended in the
Owner’s Manual, as this may result in a loss of handling control.
Never use an inner tube in a leaking wheel which is designed for a tube-
less tire. Doing so may result in an accident, causing death or serious
injury.
Do not install steel wheels.
The wheel contact surface could be damaged, and the wheel could come
off while driving, which could lead to an accident resulting in death or
serious injury. (except for vehicles with a steel spare wheel)
Use of defective wheels prohibited
Do not use cracked or deformed wheels.
Doing so could cause the tire to leak air during driving, possibly causing an
accident.
Page 800 of 1014
7766-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30D53E_(EE)
NOTICE
Replacing tire pressure warning valves and transmitters (vehicles with the
tire pressure warning system)
Because tire repair or replacement may affect the tire pressure warning
valves and transmitters, make sure to have tires serviced by any autho-
rized Lexus dealer or repairer, or another duly qualified and equipped pro-
fessional or other qualified service shop. In addition, make sure to
purchase your tire pressure warning valves and transmitters at any autho-
rized Lexus dealer or repairer, or another duly qualified and equipped pro-
fessional.
Ensure that only genuine Lexus wheels are used on your vehicle.
Tire pressure warning valves and transmitters may not work properly with
non-genuine wheels.
Page 822 of 1014
7986-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30D53E_(EE)
Right-hand drive vehicles
FuseAmpereCircuit
1STOP7.5Stop lights, high mounted stoplight
2P/SEAT1 F/R30Power seats
3FR P/OUTLET15Power outlet (front)
4P/W-B5Power window master switch
5RR P/OUTLET15Power outlet (rear)
6P/SEAT2 F/R25Power seats
7AV S20AV S
8WIPER30Windshield wipers
9WA S H20Windshield washer
10RH ECU-IG10
Navigation system, VGRS, Lexus night
view, brake system, D-SW MODULE
(Blind Spot Monitor, heated steering
wheel), pre-crash seat belts, DRS
11RH-IG10
Tension reducer, power seats, head-up
display, front right-hand door ECU,
“nanoe™”, shift lock system, electric tilt
and telescopic steering column, seat
heater/ventilator switches, smart entry &
start system antennas, tire pressure warn-
ing system receiver, driver monitor sys-
tem
12DOOR FR30
Front right-hand door control system
(outside rear view mirror defoggers,
power window)
Page 824 of 1014
8006-3. Do-it-yourself maintenance
GS450h_300h_OM_OM30D53E_(EE)
Trunk
FuseAmpereCircuit
1PSB30Pre-crash seat belts
2PTL25Power trunk lid
3RR J/B-B10Smart entry & start system
4RR S/HTR20Seat heaters (rear)
5FR S/HTR10Seat heaters/ventilators (front)
6RR FOG10Rear fog light
7DC/DC-S (HV)7.5DC/DC converter
8BATT FAN (HV)20Hybrid battery (traction battery) cooling
fan system
9SECURITY7.5SECURITY
10ECU-B NO.37.5Parking brake
11TRK OPN7.5Power trunk lid, trunk open motor
12DCM (HV)7.5No circuit
13AC INV (HV)20No circuit
14RR-IG15Radar sensor, Blind Spot Monitor
15RR ECU-IG10
Power trunk lid, parking brake, tension
reducer (rear left-hand), RR CTRL SW,
tire pressure warning system
16EPS-IG5Electric power steering system
17BACK UP7.5Back-up light
Page 862 of 1014

8357-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30D53E_(EE)
*1: Open door warning buzzer:
P. 8 4 8
*2: Driver’s and front passenger’s seat belt buzzer:
The driver’s and front passenger’s seat belt buzzer sounds to alert the
driver and front passenger that his or her seat belt is not fastened. The
buzzer sounds intermittently for 30 seconds after the vehicle reaches a
speed of 20 km/h (12 mph). Then, if the seat belt is still unfastened, the
buzzer will sound in a different tone for 90 more seconds.
(If equipped)
Tire pressure warning light
When the light comes on:
Low tire inflation pressure
such as
• Natural causes (P.
836)
• Flat tire (P. 871, 885)
Adjust the tire inflation pres-
sure to the specified level.
The light will turn off after
a few minutes. In case the
light does not turn off even
if the tire inflation pressure
is adjusted, have the sys-
tem checked by any autho-
rized Lexus dealer or
repairer, or another duly
qualified and equipped
professional.
When the light comes on
after blinking for 1 minute:
Malfunction in the tire pres-
sure warning systemHave the system checked by
any authorized Lexus dealer
or repairer, or another duly
qualified and equipped pro-
fessional.
Wa r n i n g
lightWarning light/DetailsCorrection procedure
Page 863 of 1014

8367-2. Steps to take in an emergency
GS450h_300h_OM_OM30D53E_(EE)
Front passenger detection sensor, seat belt reminder and warning buzzer
If luggage is placed on the front passenger seat, the front passenger detec-
tion sensor may cause the warning light to flash and the warning buzzer to
sound 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.
If the malfunction indicator lamp comes on while driving
The malfunction indicator lamp will come on if the fuel tank becomes com-
pletely empty. If the fuel tank is empty, refuel the vehicle immediately. The
malfunction indicator lamp will go off after several trips.
If the malfunction indicator lamp does not go off, contact any authorized
Lexus dealer or repairer, or another duly qualified and equipped professional
as soon as possible.
Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insufficient or the voltage tempo-
rarily drops, the electric power steering system warning light may come on
and the warning buzzer may sound.
When the tire pressure warning light comes on
Carry out the following procedure after the tire temperature has lowered suf-
ficiently.
Check the tire inflation pressure and adjust to the appropriate level.
If the warning light does not go out even after several minutes, check that
the tire inflation pressure is at the specified level and carry out initialization.
The warning light may come on again if the above operations are conducted
without first allowing the tire temperature to lower sufficiently.
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 caused by temperature. In
this case, adjusting the tire inflation pressure will turn off the warning light
(after a few minutes).