2007 Lexus GS450h warning

398
4-3. Do-it-yourself maintenance
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 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 wheels are used on your vehicle. 
Tire pressure warning valves and transmitters may not work properly with non-
genuine wheels.

414
4-3. Do-it-yourself maintenance
■Passenger’s side instrument panel
FuseAmpereCircuit
1ECU-IG RH10
Electric tilt and telescopic steering,
combination switch, power seat,
smart access system with push-but-
ton start, air conditioning system,
touch screen, shift lock system, tire
pressure warning system, front/rear
stabilizer system
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
4AM215Starting system
5FR DOOR RH20Front right door control system
6RR DOOR RH20Rear right door control system
7AIR SUS20AV S
8PWR OUTLET15Po w e r o u t l e t
9CIG15Cigarette lighter

When trouble arises5
427
5-1. Essential information............ 428If your vehicle needs to be 
towed .......................................... 428
If you think something is 
wrong .......................................... 435
Event data recorder ................. 436
5-2. Steps to take in an 
emergency............................ 438
If a warning light turns on or a 
warning buzzer sounds............ 438
If a warning message is 
displayed.................................... 444
If you have a flat tire (Vehicles 
with run-flat tires) ................... 460
If you have a flat tire (Vehicles 
with standard tires) .................. 461
If the hybrid system will not 
start ................................................ 471
If the shift lever cannot be 
shifted from P............................ 472
If you lose your keys .................. 473
When the electronic key 
battery is discharged ............. 474
If the 12 volt battery is 
discharged ................................. 476
If your vehicle overheats ....... 480
If the vehicle becomes  stuck ............................................ 483

438
5-2. Steps to take in an emergency
If a warning light turns on or a warning buzzer sounds...
Stop the vehicle immediately. Continuing to drive the vehicle may be dangerous.
The following warning indicates a possible problem in the brake system.
Immediately stop the vehicl e in a safe place and contact your Lexus
dealer.
*: Parking brake engaged warning buzzer:
 P. 4 5 0
Stop the vehicle immediately.
The following warning indicates the po ssibility of damage to the vehicle
that may lead to an ac cident. Immediately stop the vehicle in a safe place
and contact your Lexus dealer.
Warning lightWarning light/Details
(U.S.A.)

(Canada)
Brake system warning light (warning buzzer)*
•Low brake fluid
• Malfunction in the brake system
This light also comes on when the parking brake is not
released. If the light turns off after the parking brake is fully
released, the system is operating normally.
Warning lightWarning light/Details
Charging system warning lightIndicates a malfunction in the vehicle’s charging system
while the hybrid system is running.
Calmly perform the following actions if any of the warning lights turn on or
flash. If a light turns on or flashes, bu t then turns off, this does not necessar-
ily indicate a malfunction in the system.

5
When trouble arises
439
5-2. Steps to take in an emergency
Have the vehicle inspected by your Lexus dealer immediately.Failing 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.
*1: Electronically Controlled Brake System
Warning lightWarning light/Details
(U.S.A.)

(Canada)
Malfunction indicator lamp
Malfunction in:
• The hybrid system;
• The electronic engine control system;
• The electronic throttle control system; or
• The transmission control system.
SRS warning lightMalfunction 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*1/VSC warning light
Malfunction in:
• The electronically controlled brake system; or
• The VSC.
Electric power steering system warning light Malfunction in the EPS.
Pre-collision system warning light (if equipped)Malfunction in the pre-collision system.

440
5-2. Steps to take in an emergency
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.
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.

5
When trouble arises
441
5-2. Steps to take in an emergency
*2: Open door warning buzzer:
P. 4 4 9
*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 ve hicle has reached a speed of at lest 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.
■Front passenger detection sensor and passenger seat belt reminder
●If luggage is placed on the front passenger seat, the front passenger detection
sensor may cause the warning light to flash, 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.

442
5-2. Steps to take in an emergency
■SRS warning light
This warning light system monitors the following:
●The airbag sensor assembly
●Front airbag sensors
●The curtain shield airbag sensors
●The side and curtain shield airbag sensors
●The occupant detection sensor
●The front passenger occupant classification ECU
●“AIRBAG ON” and “AIRBAG OFF” indicator lights
●The pressure sensor
●The belt tension sensor
●The seat belt buckle switches
●The driver's seat position sensor
●The inflators
●The warning light
●The interconnecting wiring and power sources
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level. Pushing the tire
pressure warning reset switch does not turn off the tire pressure warning light.
■The tire pressure warning light may turn on due to natural causes
The tire pressure warning light may turn on due to natural causes such as natural air
leaks or tire inflation pressure changes caus ed by temperature. In this case, adjust-
ing the tire inflation pressure will turn off the warning light.