2009 TOYOTA PRIUS overheating

33
1-1. Hybrid system
1
Before driving
PRIUS_U_(OM47614U)
CAUTION
■
Road accident cautions
Observe the following precautions to reduce the risk of injury.
● Pull your vehicle off the road, put the shift lever in “P”, apply the parking
brake, turn the hybrid system off.
● Do not touch the high voltage parts, cables and connectors.
● If electric wires are exposed inside or outside your vehicle, an electric
shock may occur. Never touch exposed electric wires.
● If a fluid leak occurs, do not touch it as it may be strong alkaline electrolyte
from the hybrid battery (traction battery). If it comes into contact with your
skin or eyes, wash it off immediately with a large amount of water or if pos-
sible, boric acid solution. Seek immediate medical attention.
● If a fire occurs in the hybrid vehicle, leave the vehicle as soon as possible.
Never use a fire extinguisher that is not meant for electric fires. Using even
a small amount of water may be dangerous.
● If your vehicle needs to be towed, do so with the front wheels raised. If the
wheels with the electric motor (traction motor) are on the ground when
towing, the motor may continue to generate electricity. This may cause an
electricity leakage leading to a fire. (
P. 413)
NOTICE
■Hybrid battery air vent
● Do not put foreign objects over the air vent. The hybrid battery (traction
battery) may overheat and be damaged.
● Clean the air vent regularly to prevent the hybrid battery (traction battery)
from overheating.
● Do not wet the air vent. It may cause a short circuit and damage the hybrid
battery (traction battery).
● Do not load a large amount of water such as an aquarium into the vehicle.
If water spills over the hybrid battery (traction battery), the battery may be
damaged.

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2-1. Driving procedures
2
When driving
PRIUS_U_(OM47614U)
CAUTION
■
When taking a nap in the vehicle
Always turn the hybrid system off. Otherwise, you may accidentally move the
shift lever or depress the accelerator pedal, which could cause an accident
or fire due to hybrid system overheating. Additionally, if the vehicle is parked
in a poorly ventilated area, exhaust gases may collect and enter the vehicle,
leading to death or a serious health hazard.
■ When braking the vehicle
● When the brakes are wet, drive more cautiously. Braking distance
increases when the brakes are wet, and may cause one side of the vehicle
to brake differently than the other side. Also the parking brake may not
securely hold the vehicle.
● If the power brake assist function does not operate, do not follow other
vehicles closely and avoid downhill or sharp turns that require braking.
In this case, braking is still possible, but it will require more force on the
pedal than usual. Braking distance may also increase.
● Do not pump the brake pedal if the hybrid system stalls.
Each push on the pedal uses up your reserved brake fluid pressure.
● The brake system consists of 3 individual hydraulic systems: if one of the
systems fails, the other will still operate. In this case, the brake pedal
should be depressed more firmly than usual and braking distance
becomes longer.
Do not drive your vehicle with only a single brake system. Have your
brakes fixed immediately.

143
2-1. Driving procedures
2
When driving
PRIUS_U_(OM47614U)
Parking brake
NOTICE
■Before driving
Fully release the parking brake.
Driving the vehicle with the parking brake set will lead to brake components
overheating, which may affect braking performance and increase brake
wear.
■ When parking the vehicle
Before you leave the vehicle, set the parking brake, push the “P” position
switch and make sure that the vehicle does not move.
Sets the parking brake*
(Depressing the pedal again
releases the parking brake.)
*:Fully depress the parking
brake pedal with your left
foot while depressing the
brake pedal with your right
foot.
CanadaU.S.A.

147
2-2. Instrument cluster
2
When driving
PRIUS_U_(OM47614U)
NOTICE
■
To prevent damage to the hybr id system and its components
The hybrid system may be overheating if the high coolant temperature warn-
ing light is displayed on the touch screen. In this case, immediately stop the
vehicle in a safe place. Check the hybrid system after it has cooled com-
pletely. ( P. 454)

167
2-4. Using other
driving systems
2
When driving
PRIUS_U_(OM47614U)
■Sounds and vibrations caused by the ABS, brake assist and Enhanced
VSC
● A sound may be heard from the hybrid system compartment when the
hybrid system is started or just after the vehicle begins to move. This
sound does not indicate that a malfunction has occurred in any of these
systems.
● Any of the following conditions may occur when the above systems are
operating. None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard after the vehicle comes to a stop.
• The brake pedal may pulsate slightly after the ABS is activated.
• The brake pedal may move down slightly after the ABS is activated.
■ Reduced effectiveness of EPS
The effectiveness of EPS is reduced to prevent the system from overheating
when there is frequent steering input over an extended period of time. The
steering wheel may feel heavy as a result. Should this occur, refrain from
excessive steering input or stop the vehicle and turn the hybrid system OFF.
The system should return to normal within 10 minutes.

454
5-2. Steps to take in an emergency
PRIUS_U_(OM47614U)
If your vehicle overheats
Correction proceduresStop the vehicle in a safe place and turn off the automatic air
conditioning 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.
Remove the engine compartment cover. ( P. 361)
Check to see if the cooling fan is operating.
If the fan is operating: Wait until the engine coolant temperature gauge begins to
fall and then stop the hybrid system.
If the fan is not operating: Stop the hybrid system immediately and call your local Toy-
ota dealer.
The following may indicate that your vehicle is overheating:
The high engine coolant temperature warning light comes on:
The hybrid system may be overheating.
Follow the correction procedure as described blow.
STEP1
STEP2
STEP3
STEP4

5
When trouble arises
455
5-2. Steps to take in an emergency
PRIUS_U_(OM47614U)
After the hybrid system has
cooled down sufficiently, check
the coolant level and inspect the
radiator core (radiator) for any
leaks.
Add coolant if required.
Water can be used in an emer-
gency measure if coolant is
unavailable. (
P. 465)
Have the vehicle checked at your nearest Toyota dealer as soon as
possible.
ITY52P018
STEP5
ITY52P019
STEP6
■Overheating
In the following situations, your vehicle may be overheating.
● High coolant temperature warning light is displayed on the touch screen.
● Steam is coming from under the hood.

499
Alphabetical index
PRIUS_U_(OM47614U)
How your child should wear
the seatbelt .......................... 67
Installing child restraints ....... 111
Power window lock switch ...... 76
Power window precautions..... 78
Removed electronic key battery
precautions ........................ 393
Seat belt precautions.............. 68
Back door ............................... 56
Cleaning Exterior ................................. 342
Interior .................................. 344
Seat belts ............................. 345
Clock ........................................ 328
Condenser ............................... 369
Console box............................. 320
Cooling system Hybrid system overheating ... 454
Cruise control Cruise control ....................... 159
Cup holders ............................. 322
Curtain shield airbags .............. 89
Customizable features ............ 486
Daytime running light system ................................... 153
Defogger
Rear window......................... 213
Side mirror ............................ 213
Dimension ................................ 460
Dinghy towing ......................... 178
Display Touch screen........................ 182
Trip information ...................... 27
Do-it-yourself maintenance .... 353
Door courtesy lights ............... 315
Door pocket ............................. 323
Doors Door lock .................... 36, 49, 51
Rear door child protector ........ 52 Driver’s seat belt reminder
light .........................................426
Driving
break-in tips...........................123
Correct posture .......................87
Procedures ............................122
Winter driving tips..................173
Electronic key Replacing battery ..................392
When the electronic key battery is discharged...........448
Electric Power Steering ...........166
Emergency flashers
Switch....................................412
Emergency, in case of If a warning light turns on ......423
If the electronic key does not
operate properly..................448
If the hybrid system will not start .....................................446
If the 12 volt battery is discharged .........................449
If you have a flat tire .............436
If you lose your keys .............447
If you think something is wrong ..................................420
If your vehicle becomes stuck ...................................457
If your vehicle needs to be
towed ..................................413
If your vehicle overheats .......454
Engine
Compartment ........................360
Hood......................................357
How to start the hybrid system ................................132
If the hybrid system will not start ...............................446
Overheating...........................454
“POWER” switch ...................132
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