2010 TOYOTA PRIUS Owners Manual

5
When trouble arises
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5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
Stop the vehicle immediately.
The following warning indicates the possibility of damage to the vehi-
cle that may lead to an accident. Immediately stop the vehicle in a
safe place and contact your Toyota dealer.
Have the vehicle inspected 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 Toyota dealer immediately.
Warning lightWarning light/Details
Charging system warning light
Indicates a malfunction in the vehicle’s charging system.
Warning lightWarning light/Details
(U.S.A.)
(Canada) Malfunction indicator lamp
Malfunction in:
• The emission control system;
• The electronic engine control system;
• The electronic hybrid system control system; or
• The electronic throttle control system.
SRS warning light Malfunction in:
• The SRS airbag system;
• Front passenger occupant classification system; or
• The seat belt pretensioner system.

498 5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
Warning lightWarning light/Details
Automatic headlight leveling system warning light (if
equipped)
Indicates a malfunction in the automatic headlight level-
ing system.

(U.S.A.)

(Canada)
ABS warning lightMalfunction in:
• The ABS; or
• The brake assist system.
Brake system warning light (yellow indicator) Malfunction in the electronically controlled brake sys-
tem.
Electric power steering system warning light Malfunction in the EPS (Electric Power Steering).
Pre-collision system warn ing light (if equipped)
Indicates a malfunction in the pre-collision system.

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When trouble arises
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5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
Follow the correction procedures.
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)
*1
A door or a back door is
not fully closed.
Check that all
doors and the back
door are closed.
Low fuel level warning
light Remaining fuel
(Approximately 1.6 gal.
[6.0 L, 1.3 Imp.gal.] or
less) Refuel the vehicle.
Driver’s seat belt
reminder light (warning
buzzer)
*2
Warns the driver to fasten
his/her seat belt. Fasten the seat
belt.
(On the instrument panel)
Front passenger’s seat
belt reminder light
(warning buzzer)
*2
Warns the front passen-
ger to fasten his/her seat
belt.Fasten the seat
belt.

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PRIUS_U (OM47668U) U.S.A.
Warning lightWarning light/DetailsCorrection procedure
Tire pressure warning
light
When the light comes on:
Low tire inflation pres-
sure. Adjust the tire
inflation pressure.
When the light comes on
after blinking for 1 minute:
Malfunction in the tire
pressure warning system. Have the system
checked by your
Toyota dealer.
High coolant tempera-
ture warning light
Indicates high engine
coolant temperature P. 5 4 8
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. P. 5 0 8

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When trouble arises
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5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
*1: Open door warning buzzer:
The open door warning buzzer sounds to alert one or more of the doors is
not fully closed (with the vehicle hav
ing reached a speed of 3 mph [5 km/h]).
*2: 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 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.
■If the malfunction indicator lamp comes on while driving
First check whether the fuel tank cap is 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 Toyota dealer
as soon as possible.
■ Electric power steering warning light
When the voltage is low or drops, the electric power steering warning light
may come on.

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PRIUS_U (OM47668U) U.S.A.
■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 sensor assemblies
● The driver’s seat position sensor
● Driver’s seat belt buckle switch
● The front passenger occupant classification ECU
● The pressure sensor
● The belt tension sensor
● “AIR BAG ON” and “AIR BA G OFF” indicator lights
● Front passenger’s seat belt buckle switch
● The inflators
● The warning light
● The interconnecting wiring and power sources
■ Open moon roof reminder buzzer
The buzzer indicates that the moon roof is not fully closed with the hybrid
system off and the driver’s door opened.

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When trouble arises
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5-2. Steps to take in an emergency
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■
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.
■
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 temper-
ature. In this case, adjusting the ti re 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 repair ed tire and adjust the proper tire
inflation pressure. The ti re pressure warning light will turn off after a few
minutes.

504 5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
■If the tire pressure warning system is inoperative
The tire pressure warning system will be disabled in the following condi-
tions:
(When the condition becomes 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.
●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 condi-
tions:
(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 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.