Page 461 of 622

460
4-3. Do-it-yourself maintenance
GS_HV_U (OM30B44U)
April 27, 2009 10:09 am
CAUTION
■Tire pressure warning system operation
The tire pressure warning system may not provide warning immediately if a tire
bursts or if sudden air leakage occurs.
■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 serious 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 (radial, bias-belted or bias-ply tires).
●Do not mix summer, all season and winter 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 push the tire pressure warning reset 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.
GS450h_HV_U.book Page 460 Monday, April 27, 2009 10:10 AM
Page 483 of 622
482
4-3. Do-it-yourself maintenance
GS_HV_U (OM30B44U)
April 27, 2009 10:09 am
■Left side instrument panel
FuseAmpereCircuit
1FR WIP30Windshield wipers and washers
2RR-IG7. 5RR-IG1
3LH-IG10
Emergency flashers, seat belt preten-
sioners, headlight cleaners, exhaust
system, rear window defogger, elec-
tric cooling fans, front left door con-
trol system, rear left door control
system
4H-LP LVL7. 5Adaptive front lighting system
5A/C W/P7. 5Air conditioning system
6RAD No.310Audio system
7FR DOOR LH20Front left door control system
8RR DOOR LH20Rear left door control system
9FR S/HTR LH15Seat heaters, seat heaters and venti-
lators
GS450h_HV_U.book Page 482 Monday, April 27, 2009 10:10 AM
Page 485 of 622
484
4-3. Do-it-yourself maintenance
GS_HV_U (OM30B44U)
April 27, 2009 10:09 am
■Right side instrument panel
FuseAmpereCircuit
1ECU-IG RH10
Tilt and telescopic steering, combina-
tion switch, power seat, smart access
system with push-button start, air
conditioning system, touch screen,
shift lock system, tire pressure warn-
ing system, front/rear stabilizer sys-
tem
2FR S/HTR RH15Seat heaters, seat heaters and venti-
lators
3RH-IG7. 5
Front right door control system, rear
right door control system, seat belt
pretensioners, transmission, seat
heaters, seat heaters and ventilators
4AM27. 5Starting system
5FR DOOR RH20Front right door control system
6RR DOOR RH20Rear right door control system
GS450h_HV_U.book Page 484 Monday, April 27, 2009 10:10 AM
Page 487 of 622
486
4-3. Do-it-yourself maintenance
GS_HV_U (OM30B44U)
April 27, 2009 10:09 am
■Luggage compartment
FuseAmpereCircuit
1RR TAIL10Tail lights, license plate lights
2STOP LP R10High mounted stoplights, stoplights
3STOP LP L10Stoplights, back-up light
4RR FOG7. 5
5RR-B10Tr u n k l i g h t
6RR-IG110Pre-collision seat belt, seat belt pre-
tensioners
7RR-IG210
8PSB30Pre-collision seat belt
9RR S/SHADE7. 5Rear sunshade
10RH J/B-B30FR DOOR RH, RR DOOR RH,
AM2
11LH J/B-B30FR DOOR LH, RR DOOR LH,
RAD No.3
12R/B-B15D/C c ut
GS450h_HV_U.book Page 486 Monday, April 27, 2009 10:10 AM
Page 509 of 622

508
5-1. Essential information
GS_HV_U (OM30B44U)
April 27, 2009 10:09 am
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
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 a system to record
data in a crash or a near car crash event. This is called an Event Data
Recorder (EDR).
GS450h_HV_U.book Page 508 Monday, April 27, 2009 10:10 AM
Page 512 of 622

5
When trouble arises
511
5-2. Steps to take in an emergency
GS_HV_U (OM30B44U)
April 27, 2009 10:09 am
Have the vehicle inspected immediately.
Failure 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
(U.S.A.)
(Canada)
Malfunction indicator lamp Malfunction in:
• The emission control system;
• The electronic engine control system;
• The hybrid system;
• The electronic throttle control system; or
• The transmission control system.
SRS warning light
Malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system.
(U.S.A.)
(Canada)
ABS warning lightMalfunction in:
•The ABS; or
• The brake assist system.
ECB (Electronically controlled brake system) warning light Malfunction in the electronically controlled brake system.
Electric power steering system warning light
Malfunction in the EPS.
“PCS” warning light (if equipped)Malfunction in the pre-collision system.
Slip indicatorMalfunction in the Enhanced VSC.
The indicator will blink when Enhanced VSC, TRAC or hill-
start assist control is operational. ( →P. 2 1 5 )
GS450h_HV_U.book Page 511 Monday, April 27, 2009 10:10 AM
Page 513 of 622

512
5-2. Steps to take in an emergency
GS_HV_U (OM30B44U)
April 27, 2009 10:09 am
Have the malfunction repaired immediately.After taking the specified steps to correct the suspected problem, check
that the warning light turns off.
Warning lightWarning light/DetailsCorrection procedure
Open door warning light
(warning buzzer)*2
A door or the trunk is not
fully closed.
Check that all doors and the
trunk are closed.
Low fuel level warning light Remaining fuel
(Approximately 2.6 gal. [10
L, 2.2 Imp.gal.] or less)
Refuel the vehicle.
Driver’s seat belt reminder
light (warning buzzer)*3
Warns the driver to fasten
his/her seat belt.Fasten the seat belt.
(on the center panel)
Front passenger’s seat belt
reminder light
(warning buzzer)*
3
Warns the front passenger to
fasten his/her seat belt.
Fasten the seat belt.
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 checked by
your Lexus dealer.
GS450h_HV_U.book Page 512 Monday, April 27, 2009 10:10 AM
Page 514 of 622

5
When trouble arises
513
5-2. Steps to take in an emergency
GS_HV_U (OM30B44U)
April 27, 2009 10:09 am
*2: Open door warning buzzer:
→P. 5 2 4
*
3: Driver’s and front passenger’s seat belt reminder buzzer:
The driver’s and front passenger’s seat belts reminder sounds to alert the driver
and front passenger that his or her seat belt is not fastened. The buzzer sounds
intermittently for 10 seconds 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
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.
■If the malfunction indicator lamp comes on while driving
First check the following:
●Is your vehicle low on gas?
If it is, refuel the vehicle immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go off after taking several driving trips.
If the light does not go off even after several trips, contact your Lexus dealer as soon
as possible.
GS450h_HV_U.book Page 513 Monday, April 27, 2009 10:10 AM