2012 TOYOTA SIENNA Owners Manual

5
When trouble arises
737
5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
■
SRS warning light
This warning light system monitors the airbag sensor assembly, front airbag
sensors, side and curtain shield airbag sensors, curtain shield airbag sen-
sors, driver’s seat position sensor, driver’s seat belt buckle switch, front pas-
senger occupant classification system (ECU and sensors), “AIR BAG ON”
indicator light, “AIR BAG OFF” indicator light, front passenger’s seat belt
buckle switch, seat belt pretensioner assemblies, inflators, interconnecting
wiring and power sources. ( P. 168)
■ 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 passen-
ger is not sitting in the seat.
● If a cushion is placed on the seat, the sensor may not detect a passen-
ger, and the warning light may not operate properly.
■ Electric power steering system warning light
When the voltage is low drops, the electric power steering system warning
light may come on.

738 5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
■If the malfunction indicator lamp comes on while driving
First check the following:
● Is the fuel tank empty?
If it is, fill the fuel tank immediately.
● Is the fuel tank cap loose?
If it is, tighten it securely.
The malfunction indicator lamp will go off after taking several driving trips.
If the malfunction indicator lamp does not go off even after several trips, con-
tact your Toyota dealer as soon as possible.
■
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 will not turn off the tire
pressure warning light.
■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 inflat ion pressure changes caused by tem-
perature. In this case, adjusting the tire inflation pressure will turn off the
warning light (after a few minutes).
■When a tire is replaced with a spare tire (vehicles with compact
spare tire)
The compact spare tire is not equipped with a 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 has been replaced with the spare
tire. Replace the spare tire with the re paired tire and adjust the tire infla-
tion pressure. The tire pressure wa rning light will go off after a few min-
utes.

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When trouble arises
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5-2. Steps to take in an emergency
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■If the tire pressure warning system is inoperative
The tire pressure warning system will be disabled in the following condi-
tions:
(When the condition be
comes normal, the system will work properly.)
●If tires not equipped with tire pressure warning valves and transmit-
ters are used.
●If the ID code on the tire pressure warning valves and transmitters is
not registered in the tire pressure warning computer.
The tire pressure warning system may be disabled in the following condi-
tions:
(When the condition be comes 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 there is a lot of snow or ice on the vehicle, in particular around the
wheels or wheel housings.
●If non-genuine Toyota wheels are used. (Even if you use Toyota
wheels, the tire pressu re warning system may not work properly with
some types of tires.)
●If tire chains are used.

740 5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
■If the tire pressure warning light frequently comes on after blinking
for 1 minute
Vehicles without a smart key system
If the tire pressure warning light frequently comes on after blinking 1
minute when the engine switch is turned to the “ON” position, have it
checked by your Toyota dealer.
Vehicles with a smart key system
If the tire pressure warning light frequently comes on after blinking 1
minute when the “ENGINE START STOP” switch is turned to IGNITION
ON mode, have it checked by your Toyota dealer.
■ Customization that can be co nfigured at Toyota dealer
The vehicle speed linked seat belt reminder buzzer can be disabled.
(Customizable features P. 815) However, Toyota recommends that the
seat belt reminder buzzer be operational to alert the driver and front passen-
ger when seat belts are not fastened.

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When trouble arises
741
5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
CAUTION
■When the electric power steering system warning light comes on
The steering wheel may become extremely heavy.
If the steering wheel becomes heavier than usual when operating, hold
firmly and operate using more force than usual.
■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 a tire is flat, change it with the spare tire and have the
flat tire repaired by the nearest Toyota dealer.
• Avoid abrupt maneuvering and brak ing. If the vehicle tires deterio-
rate, you could lose control of th e steering wheel or the brakes.
●Vehicles with run-flat tires:
• Decelerate to the lowest appropr iate 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 Toyota dealer.
• Avoid abrupt maneuvering and brak ing. If the vehicle tires deterio-
rate, you could lose control of th e steering wheel or the brakes.

742 5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
CAUTION
■If a blowout or sudden air leakage should occur
The tire pressure warning system may not activate immediately.
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly
when cold and inflated to the inflation pressure recommended by the
vehicle manufacturer on the vehicle placard or tire inflation pressure
label (tire and load information label). (If your vehicle has tires of a differ-
ent size than the size indicated on the vehicle placard or tire inflation
pressure label [tire and load information label], you should determine the
proper tire inflation pr essure for those tires.)
As an added safety feature, your vehicle has been equipped with a tire
pressure monitoring system (TPMS-ti re pressure warning system) that
illuminates a low tire pressure telltal e (tire pressure warning light) when
one or more of your tires is significantly under-inflated. Accordingly,
when the low tire pressu re telltale (tire pressure warning light) illumi-
nates, you should stop and check your tires as soon as possible, and
inflate them to the proper pressure. Driving on a significantly under-
inflated tire causes the tire to overheat and can lead to tire failure.
Under-inflation also reduces fuel effi ciency and tire tread life, and may
affect the vehicle’s handling and stopping ability.
Please note that the TPMS (tire pressure warning system) is not a sub-
stitute for proper tire main tenance, and it is the driver’s responsibility to
maintain correct tire pressure, even if under-inflation has not reached the
level to trigger illu mination of the TPMS low tire pressure telltale (tire
pressure warning light).

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When trouble arises
743
5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
CAUTION
Your vehicle has also been equipped with a TPMS (tire pressure warning
system) malfunction indicator to indi
cate when the system is not operat-
ing properly. The TPMS (tire pressure warning system) malfunction indi-
cator is combined with the low tire pressure telltale (tire pressure
warning light). When the system det ects a malfunction, the telltale will
flash for approximately one minute an d then remain continuously illumi-
nated. This sequence will continue upon subsequent vehicle start-ups as
long as the malfunction exists. When the malfunction indi cator is illumi-
nated, the system may not be able to detect or signal low tire pressure
as intended.
TPMS (tire pressure warning system) malfunctions may occur for a vari-
ety of reasons, including the installati on of replacement or alternate tires
or wheels on the vehicle that prevent the TPMS (tire pressure warning
system) from functioning properly. Always check the TPMS (tire pres-
sure warning system) malfunction te lltale after replacing one or more
tires or wheels on your vehicle to ensure that the replacement or alter-
nate tires and wheels allow the TPMS (tire pressure warning system) to
continue to function properly.
NOTICE
■Precaution when installing a different tire
When a tire of a different specification or maker is installed, the tire pres-
sure warning system may not operate properly.

744
5-2. Steps to take in an emergency
SIENNA_U (OM45477U)
If a warning message is displayed
: If equipped
The multi-information display shows warnings of system malfunc-
tions or incorrectly performed operations. When a message is
shown, perform corrections as indicated in the message.
Master warning light
The master warning light comes on or flashes when a message is
being shown on the multi-information display.
Multi-information display
Warning message
Correction procedure
■ Warning buzzer
A buzzer may sound when a warning message is shown on the
multi-informat ion display.
■ If the warning message is shown again after its correction
procedure has been performed
Contact your Toyota dealer as soon as possible.