2010 Lexus GS450h warning light

When trouble arises5
521
GS_HV_U (OM30C81U)
January 28, 2010 11:33 am
5-1. Essential information
Emergency flashers............... 522
If your vehicle needs 
to be towed ............................ 523
If you think something is 
wrong ....................................... 531
Event data recorder .............. 5325-2. Steps to take in an 
emergency
If a warning light turns 
on or a warning buzzer 
sounds..................................... 534
If a warning message is 
displayed................................ 543
If you have a flat tire (Vehicles 
with standard tires) ............. 560
If you have a flat tire (Vehicles 
with run-flat tires)................ 570
If the hybrid system will 
not start .................................. 572
If the shift lever cannot be 
shifted from “P”.................... 573
If you lose your keys ............... 574
If the electronic key does not 
operate properly .................. 575
If the 12 volt battery is 
discharged ............................ 578
If your vehicle overheats ...... 581
If the vehicle becomes 
stuck........................................ 584
If your vehicle has to be stopped 
in an emergency .................. 586

534
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
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 vehicle in a safe place and contact your Lexus
dealer.
*1: Parking brake engaged warning buzzer:
P. 5 4 9
Stop the vehicle immediately.
The following warning indicates the possibility of damage to the vehicle
that may lead to an accident. 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)*1
•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 light
Malfunction in the vehicle’s charging system.
Calmly perform the following actions if any of the warning lights turn on or
flash. If a light turns on or flashes, but then turns off, this does not necessar-
ily indicate a malfunction in the system.

5
When trouble arises
535
5-2. Steps to take in an emergency
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
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 light
Malfunction 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.

536
5-2. Steps to take in an emergency
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
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/Details
Slip indicator
Malfunction in the Enhanced VSC.
The indicator will blink when Enhanced VSC, TRAC or hill-
start assist control is operational. (P. 2 1 5 )
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.

5
When trouble arises
537
5-2. Steps to take in an emergency
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
*2: Open door warning buzzer:
P. 5 4 8
*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
(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.
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.

538
5-2. Steps to take in an emergency
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
■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.
■SRS warning light
This warning light system monitors the following:
●The airbag sensor assembly
●Front airbag sensors
●The curtain shield and rear side airbag sensors
●The side and curtain shield airbag sensors
●The front passenger occupant classification ECU
●“AIR BAG ON” and “AIR BAG 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

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When trouble arises
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5-2. Steps to take in an emergency
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
■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 caused by temperature. In this case, adjust-
ing the tire inflation pressure will turn off the warning light (after a few minutes).
■When a tire is replaced with a spare tire
The compact spare tire is not equipped with the tire pressure warning valve and
transmitter. If a tire goes flat, the tire pressure warning light will not turn off even
though the flat tire is replaced with the spare tire. Replace the spare tire with the
repaired tire and adjust the proper tire inflation pressure. The tire pressure warning
light will turn off after a few minutes.
■If the tire pressure warning system is inoperative
The tire pressure warning system will be disabled in the following conditions:
(When the condition becomes normal, the system will work properly.)
●If tires not equipped with tire pressure warning valves and transmitters are used.
●If the ID code on the tire pressure warning valves and transmitters is not regis-
tered in the tire pressure warning computer.
●If the tire pressure warning select switch is set to a different tire setting.
●If the tire inflation pressure is 73 psi (500 kPa, 5.1 kgf/cm2 or bar) or higher.
The tire pressure warning system may be disabled in the following conditions:
(When the condition becomes normal, the system will work properly.)
●If electronic devices or facilities using similar radio wave frequencies are nearby.
●If a radio set at similar frequencies is in use in the vehicle.
●If a window tint that affects the radio wave signals is installed.
●If there is a lot of snow or ice on the vehicle, in particular around the wheels or
wheel housings.
●If non-genuine Lexus wheels are used. (Even if you use Lexus wheels, the tire
pressure warning system may not work properly with some types of tires.)
●If tire chains are used.

540
5-2. Steps to take in an emergency
GS_HV_U (OM30C81U)
October 13, 2015 12:41 pm
■If the tire pressure warning light comes on after blinking for 1 minute frequently
If the tire pressure warning light comes on after blinking for 1 minute frequently
when the “POWER” switch is turned to ON mode, have it checked by your Lexus
dealer.
CAUTION
■If the tire pressure warning light comes on
Be sure to observe the following precautions. Failure to do so could cause loss of
vehicle control and result in death or serious injury.
●Vehicles with standard tires:
• Stop your vehicle in a safe place as soon as possible. Adjust the tire inflation
pressure immediately.
• If the tire pressure warning light comes on even after tire inflation pressure
adjustment, it is probable that you have a flat tire. Check the tires. If the tire is
flat, change to the spare tire and have the flat tire repaired by the nearest
Lexus dealer.
• Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you
could lose control of the steering wheel or the brakes.
●Vehicles with run-flat tires:
• Decelerate to the lowest appropriate speed as soon as possible. Do not drive
over 55 mph (90 km/h).
• Check and adjust the tire inflation pressure immediately.
• If the tire pressure warning light comes on even after tire inflation pressure
adjustment, it is probable that you have a flat tire. Have the tire replaced by
the nearest Lexus dealer.
• Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you
could lose control of the steering wheel or the brakes.
■If a blowout or sudden air leakage should occur
The tire pressure warning system may not activate immediately.