Page 660 of 860

660
GS450h_U (OM30D01U)
6-3. Do-it-yourself maintenance
NOTICE
■Repairing or replacing tires, wheels, tire pressure warning valves, transmitters
and tire valve caps
●When removing or fitting the wheels, tires or the tire pressure warning valves and
transmitters, contact your Lexus dealer as the tire pressure warning valves and
transmitters may be damaged if not handled correctly.
●Make sure to install the tire valve caps. If the tire valve caps are not installed,
water could enter the tire pressure warning valves and the tire pressure warning
valves could be bound.
●When replacing tire valve caps, do not us e tire valve caps other than those speci-
fied. The cap may become stuck.
■To avoid damage to the tire pressu re warning valves and transmitters
When a tire is repaired with liquid seal ants, the tire pressure warning valve and
transmitter may not operate properly. If a liquid sealant is used, contact your Lexus
dealer or other qualified service shop as soon as possible. Make sure to replace
the tire pressure warning valve and transmitter when replacing the tire. ( P. 6 5 3 )
■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.
■Low profile tires (except 225/50R17 tires)
Low profile tires may cause greater damage than usual to the tire wheel when sus-
taining impact from the road surface. Th erefore, pay attention to the following:
●Be sure to use proper tire inflation pressure. If tires are under-inflated, they may
be damaged more severely.
●Avoid potholes, uneven pavement, curbs and other road hazards. Failure to do so
may lead to severe tire and wheel damage.
■If tire inflation pressure of each tire becomes low while driving
Do not continue driving, or your tires and/or wheels may be ruined.
Page 661 of 860
661
GS450h_U (OM30D01U)6-3. Do-it-yourself maintenance
6
Maintenance and care
Tire inflation pressure
The recommended cold tire infla-
tion pressure and tire size are dis-
played on the tire and loading
information label. ( P. 790)
Tire inflation pressure
Page 662 of 860

662
GS450h_U (OM30D01U)
6-3. Do-it-yourself maintenance
Ti r e v a l v e
Tire pressure gauge
Remove the tire valve cap.
Press the tip of the tire pressure gauge onto the tire valve.
Read the pressure using the gauge gradations.
If the tire inflation pressure is not at the recommended level, adjust the
pressure.
If you add too much air, press the center of the valve to deflate.
After completing the tire inflation pressure measurement and adjust-
ment, apply soapy water to the valve and check for leakage.
Put the tire valve cap back on.
■Tire inflation pressure check interval
You should check tire inflation pressure every two weeks, or at least once a month.
Do not forget to check the spare.
■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 your Lexus dealer.
Inspection and adjustment procedure
1
2
1
2
3
4
5
6
Page 663 of 860

GS450h_U (OM30D01U)
6636-3. Do-it-yourself maintenance
6
Maintenance and care
■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 mile or 1.5 km, 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 pressure 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 inflation pres-
sure to be higher after driving.
●Never exceed the vehicle capacity weight.
Passengers and luggage weight should be placed so that the vehicle is balanced.
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 leak-
age, which could result in an accident. If the caps are lost, replace them as soon as
possible.
Page 665 of 860

GS450h_U (OM30D01U)
6656-3. Do-it-yourself maintenance
6
Maintenance and care
■When replacing wheels
The wheels of your vehicle are equipped with tire pressure warning valves and trans-
mitters that allow the tire pressure warnin g system to provide advance warning in the
event of a loss in tire inflation pressure. Whenever wheels are replaced, tire pressure
warning valves and transmitte rs must be installed. (P. 6 5 3 )
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 tubeless tire.
Doing so may result in an accident, causing death or serious injury.
NOTICE
■Replacing tire pressure warning valves and transmitters
●Because tire repair or replacement may affect the tire pressure warning valves
and transmitters, make sure to have tires serviced by your Lexus dealer or other
qualified service shop. In addition, make sure to purchase your tire pressure
warning valves and transmitters at your Lexus dealer.
●Ensure that only genuine Lexus wh eels are used on your vehicle.
Tire pressure warning valves and transmitters may not work properly with non-
genuine wheels.
Page 680 of 860
680
GS450h_U (OM30D01U)
6-3. Do-it-yourself maintenance
■Passenger’s side instrument panel
FuseAmpereCircuit
1P/ S E AT 1 F/ R30Po w e r s e a t s
2FR P/OUTLET15Po w e r o u t l e t ( f r o n t )
3RR P/OUTLET15Power outlet (rear)
4P/ S E AT 2 F/ R25Po w e r s e a t s
5AV S20AV S
6STRG HTR15Heated steering wheel
7WA S H20Windshield washer
8RH ECU-IG10
Navigation system, pre-collision seat belts,
air conditioning system, ECB, Lexus night
view, yaw rate and G sensor
9RH-IG10
Tension reducer, seat heater/ventilator
switches, front right-hand door ECU, CAN
gateway ECU, tire pressure warning system,
power seats
10DOOR FR30
Front right-hand door control system (out-
side rear view mirror defoggers, power win-
dow)
11DOOR RR30Power window (rear right-hand)
12RAD NO.230Audio system
13AM27. 5Power management system
Page 682 of 860
682
GS450h_U (OM30D01U)
6-3. Do-it-yourself maintenance
■Trunk
FuseAmpereCircuit
1PSB30Pre-collision seat belts
2PTL25Power trunk opener and closer
3RR J/B-B10Smart access system with push-button start
4RR S/HTR20Seat heaters (rear)
5FR S/HTR10Seat heaters/ventilators (front)
6RR FOG10No circuit
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 opener and closer
12DCM (HV)7. 5DCM
13AC INV (HV )20Po w e r o u t l e t ( 1 2 0 V AC )
14RR-IG15Radar sensor, Blind Spot Monitor
15RR ECU-IG10
Power trunk opener and closer, parking
brake, tension reducer (rear left-hand), RR
CTRL SW, tire pressure warning system
16EPS-IG5Electric power steering system
17BACK UP7. 5Back-up lights
Page 715 of 860

7157-2. Steps to take in an emergency
GS450h_U (OM30D01U)
7
When trouble arises
*1: Open door warning buzzer: P. 7 2 8
*2: Driver’s seat belt buzzer:
The driver’s seat belt buzzer sounds to al ert the driver that his or her seat belt is
not fastened. Once the power switch is turned to ON mode, the buzzer sounds
for 6 seconds. If the vehicle reaches a speed of 12 mph (20 km/h), the buzzer
sounds once. If the seat belt is still un fastened after 30 seconds, the buzzer will
sound intermittently for 10 seconds. Then, if the seat belt is still unfastened, the
buzzer will sound in a differ ent tone for 20 more seconds.
Front passenger’s seat belt buzzer:
The front passenger’s seat belt buzzer soun ds to alert the front passenger that his
or her seat belt is not fastened. The buzzer sounds once if the vehicle reaches a
speed of 12 mph (20 km/h). If the seat be lt is still unfastened after 30 seconds,
the buzzer will sound intermittently for 10 seconds. Then, if the seat belt is still
unfastened, the buzzer will sound in a different tone for 20 more seconds.
Tire pressure warning light
When the light comes on:
Low tire inflation pressure such
as
• Natural causes ( P. 7 1 7 )
• Flat tire ( P. 74 9 )
Adjust the tire inflation pressure
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 system
checked by your Lexus
dealer.
When the light comes on after
blinking for 1 minute:
Malfunction in the tire pressure
warning system
Have the system checked by
your Lexus dealer.
Warning lightWarning light/DetailsCorrection procedure