2010 TOYOTA PRIUS sensor

251
2-4. Using other
driving systems
2
When driving
PRIUS_U (OM47668U) U.S.A.
■Obstacles not detected
The sensor cannot detect plastic obstacles such as pylons. There may also
be occasions when the radar sensor cannot detect pedestrians, animals,
bicycles, motorcycles, trees, or snowdrifts.
■ The pre-collision system is operational when
● Pre-collision seat belts:
• Vehicle speed is above 3 mph (5 km/h).
• The relative speed difference between your vehicle and another vehi-
cle that is ahead of your vehicle, or the speed at which your vehicle is
approaching an obstacle is greater than 18 mph (30 km/h).
• The front occupants are wearing a seat belt.
● Pre-collision brake assist:
• Vehicle speed is above 18 mph (30 km/h).
• The relative speed difference between your vehicle and another vehi-
cle that is ahead of your vehicle, or the speed at which your vehicle is
approaching an obstacle is greater than 18 mph (30 km/h).
• The brake pedal is depressed.
● Pre-collision braking:
• The pre-collision braking off button is not pressed.
• Vehicle speed is above 9 mph (15 km/h).
• The relative speed difference between your vehicle and another vehi-
cle that is ahead of your vehicle, or the speed at which your vehicle is
approaching an obstacle is greater than 9 mph (15 km/h).

254 2-4. Using other driving systems
PRIUS_U (OM47668U) U.S.A.
CAUTION
■Handling the radar sensor
Observe the following to ensure the pre-collision system can function effec-
tively.
● Keep the sensor and grille cover clean at all time. 
Clean the sensor and grille cover with a soft cloth so you do not mark or
damage them.
● Do not subject the sensor or surrounding area to a strong impact. 
If the sensor moves even slightly off position, the system may malfunction.
If the sensor or surrounding area is subject to a strong impact, always
have the area inspected and adjusted by your Toyota dealer.
● Do not disassemble the sensor.
● Do not attach accessories or stickers to the sensor, grille cover or sur-
rounding area.
● Do not modify or paint the sensor and grille cover.
■ Limitations of the pre-collision system
Do not rely on the pre-collision system. Always drive safely, taking care to
observe your surroundings and checking for any obstacles or other road
hazards.

469
4-3. Do-it-yourself maintenance
4
Maintenance and care
PRIUS_U (OM47668U) U.S.A.
FUSEAmpereCircuit
15 P FR DOOR 25A Power windows
16 D FR DOOR 25A Power windows
17 DOOR RR 25A Power windows
18 DOOR RL 25A Power windows
19 S/ROOF 30A Electric moon roof
20 ECU-IG NO.1 10A Electric cooling fans, multiplex
communication system
21 ECU-IG NO.2 10A Driver support system, Pre-Colli-
sion System, LKA system, inside
rear view mirror, garage door
opener, yaw rate & G sensor,
brake system, electric power
steering, navigation system, elec-
tric moon roof, tire pressure warn-
ing system, seat belt
pretensioners, audio system,
emergency flashers, turn signal
lights, windshield wipers, headlight
cleaner
22 GAUGE 10A Headlight leveling system, front
passenger’s seat belt reminder
light, gauges and meters
23 A/C 10A Air conditioning system, Solar
Ventilation System, Remote Air
Conditioning System
24 WASHER 15A Windshield washer

470 4-3. Do-it-yourself maintenance
PRIUS_U (OM47668U) U.S.A.
FUSEAmpereCircuit
25 RR WIP 20A Rear window wiper and washer
26 WIP 30A Windshield wipers
27 MET 7.5A Gauges and meters
28 IGN 10ABrake system, driver support sys-
tem, multiport fuel injection sys-
tem/sequential multiport fuel
injection system, SRS airbag sys-
tem, occupant detection sensor,
power windows, smart key system
29 PANEL 10AAir conditioning system, emer-
gency flashers, seat heaters,
transmission, “P” position switch,
navigation system, Solar Ventila-
tion System, Remote Air Condi-
tioning System, advanced parking
guidance system, headlight
cleaner, front passenger’s seat
belt reminder light, headlight level-
ing system, glove box light, clock,
audio system
30 TAIL 10AHeadlight leveling system, park-
ing lights, tail lights, license plate
lights, front fog lights, side marker
lights

494
5-1. Essential information
PRIUS_U (OM47668U) U.S.A.
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 follow-
ing information:
● Gasoline engine speed
● Whether the brake pedal was applied or not
● Vehicle speed
● 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
The information above is intended to be used for the purpose of
improving vehicle safety performan ce. Unlike general data recorders,
the EDR does not record sound data such as conversation between
passengers.
Your vehicle has computers that monitor and control certain aspects
of your vehicle. These computers assi st in driving and maintaining
optimal vehicle performance.
Besides storing data useful for troubleshooting, there is an event
data recorder (EDR) that records data in a crash or a near car crash
event.

502 5-2. Steps to take in an emergency
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.

5
When trouble arises
503
5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
■
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.

5
When trouble arises
513
5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
Warning messageDetailsCorrection
procedure
(If equipped) Indicates that the pre-collision
system is not currently func-
tional because the grille or the
sensor is dirty.
This message also appears
when the pre-collision system
is not functional due to over-
heating. Check the grille
and the sensor and
clean them if they
are dirty. In case of
overheating, the
system will become
functional once the
system cools
down.
(Flashing) 
(If equipped) Indicates that the radar cruise
control sensor is dirty or cov-
ered with ice.
Clean the sensor.
(Flashing) 
(If equipped) Indicates that the radar cruise
control system is unable to
judge vehicle-to-vehicle dis-
tance.
If the windshield
wipers are on, turn
them off or set
them to either the
intermittent or the
slow mode.