engine TOYOTA PRIUS 2010 3.G Workshop Manual

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.

5
When trouble arises
497
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.

500 5-2. Steps to take in an emergency
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

5
When trouble arises
509
5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
Stop the vehicle immediately.
A buzzer sounds and a warning message is shown on the multi-infor-
mation display. The following warnin gs indicate the possibility of dam-
age to the vehicle that may lead to an accident. Immediately stop the
vehicle in a safe place and contact your Toyota dealer.
Warning messageDetails
Indicates an abnormal engine oil pressure. The warning light may turn on if the engine oil pres-
sure is too low.
Indicates a malfunction in the hybrid system.

512 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 message turns off.
Warning messageDetailsCorrection procedure
(U.S.A. only) Indicates that the engine oil is
scheduled to be changed.
A buzzer also sounds.
Check the engine
oil, and change if
necessary.
Comes on approximately 4500
miles (7200 km) after the
engine oil is changed. (The
indicator will not work properly
unless the oil maintenance
data has been reset).
(U.S.A. only) Indicates that the engine oil
should be changed.
A buzzer also sounds.
Check and change
the engine oil.
Comes on approximately 5000
miles (8000 km) after the
engine oil is changed (and the
oil maintenance data has been
reset).

516 5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
Warning messageDetailsCorrection procedure
EV-Drive Mode cannot be
switched to. A buzzer also sounds. Use the EV-Drive
Mode when it
becomes available.
The EV-Drive Mode has been
automatically cancelled. A buzzer also sounds. Drive normally for a
short time.
■ After changing the engine oil (U.S.A. only)
Make sure to reset the oil maintenance data. ( P. 428)
■ Approach warning message
In the following instances, there is the possibility that the approach warning
will not activate even when the vehicle-to-vehicle distance decreases.
● When your vehicle and the vehicle ahead are traveling at the same
speed or the vehicle ahead is traveling more quickly than your vehicle.
● When the vehicle ahead is traveling at very low speed.
● Immediately after cruise control speed is set.
● At the instant the accelerator pedal is depressed.

522 5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
InteriorbuzzerExterior buzzerWarning messageDetailsCorrection procedure
Once 
(Flashing)The elec-
tronic key
does not
operate
properly.
P. 542
 Power
was
turned off
due to
the auto-
matic
power off
function.Next time when
starting the
hybrid system,
increase the
engine speed
slightly and
maintain that
level for approxi-
mately 5 min-
utes to recharge
the battery.
■ Changing the engine oil
Make sure to reset oil change system.

5
When trouble arises
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5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
NOTICE
■
While the engine oil level warning is displayed
Continued engine operation with low engine oil will damage the engine.
■ Engine oil maintenance message
The warning message is based on the projected driving range after engine
oil maintenance message is reset. 
The system does not monitor the purity of the engine oil.

5
When trouble arises
545
5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
■
Starting the hybrid system when the 12 volt battery is discharged
The hybrid system cannot be started by push-starting. In addition, the shift
position may not changed from “P”.
■ Avoiding a discharged 12 volt battery
● Turn off the headlights and the audio system while the hybrid system is
turned off.
● Turn off any unnecessary electrical components when the vehicle is run-
ning at a low speed for an extended period, such as in heavy traffic, etc.
■ When the 12 volt battery is removed or discharged
The hybrid system may not start. (
P. 438)
Start the engine of the second vehicle. Increase the engine
speed slightly and maintain at that level for approximately 5
minutes to recharge the 12 volt battery of your vehicle.
Turn the “POWER” switch to ACCESSORY mode.
Maintain the engine speed on the second vehicle and turn
the “POWER” switch to ON mode, then start your vehicle’s
hybrid system.
Make sure the “READY” indicator comes on. If the indicator
does not come on, contact your Toyota dealer.
Once the vehicle’s hybrid syst em has started, remove the
jumper cables in the exact reverse order in which they were
connected.
Once the hybrid system starts, ha ve the vehicle checked at your
Toyota dealer as soon as possible.STEP4
STEP5
STEP6
STEP7
STEP8

548
5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
If your vehicle overheats
Correction procedures■ If the high coolant temperatur e warning light comes on or
flashes
Stop the vehicle in a safe place and turn off the air condition-
ing system.
Check to see if steam is coming out from under the hood.
If you see steam: 
Stop the hybrid system. Carefully lift the hood after the
steam subsides and then restart the hybrid system.
If you do not see steam: 
Leave the hybrid system operating and carefully lift the
hood.
The following may indicate that your vehicle is overheating:
● The high coolant temperature warn ing light comes on or flashes:
The engine may be overheating.
● “HYBRID SYSTEM OVERHEAT” is shown on the multi-informa-
tion display: 
The power control unit may be overheating.
Follow the correction procedure as described below.
STEP1
STEP2