2012 TOYOTA PRIUS overheating

41
1-1. Hybrid system
1
Before driving
NOTICE
■
Hybrid battery (traction battery) air vent
●Do not put foreign objects near 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 or allow foreign substances to enter the air vent as this may
cause a short circuit and damage the hybrid battery (traction battery).
● Do not carry large amounts of water such as water cooler bottles in the
vehicle. If water spills onto the hybrid battery (traction battery), the battery
may be damaged. Have the vehicle inspected by your Toyota dealer.
● If the rear seat belt becomes separated from the guide ( P. 103), it could
obstruct the hybrid battery (traction battery) air vent. Set the rear seat belt
into the guide to use.

189
2-1. Driving procedures
2
When driving
CAUTION
■
When taking a nap in the vehicle
Always turn the hybrid system off. Otherwise, if you accidentally move the
shift lever or depress the accelerator pedal, this 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
●When the brakes are wet, drive more cautiously.
Braking distance increases when the brakes are wet, and this 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 electronically controlled assist function does not operate, do not fol-
low other vehicles closely and avoid downhill or sharp turns that require
braking.
In this case, braking is still possible, but the brake pedal should be
depressed more firmly than usual. Also, the braking distance will increase.
● The brake system consists of 2 individual hydraulic systems; if one of the
systems fails, the others will still operate. In this case, the brake pedal
should be depressed more firmly than usual and the braking distance will
increase. If this happens, do not continue to drive the vehicle. If the brake
system warning light (red indicator) comes on while driving, immediately
stop the vehicle in a safe place and contact your Toyota dealer.

212
2-1. Driving procedures
Parking brake
■Parking brake engaged warning buzzer
P. 493
■ Usage in winter time
P. 317
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.
To set the parking brake, fully
depress the parking brake
pedal with your left foot while
depressing the brake pedal
with your right foot.
(Depressing the pedal again
releases the parking brake.)
U.S.A.
Canada

218 2-2. Instrument cluster
CAUTION
■To prevent an accident
NOTICE
■To prevent damage to the engine and its components
The engine may be overheating if the high coolant temperature warning light
comes on or flashes. In this case, immediately stop the vehicle in a safe
place, and check the engine after it has cooled completely. ( P. 549)
Do not place anything or attach a sticker
in front of the instrument cluster. The item
may obscure or obstruct the display, or
could reflect off the display, possibly
causing an accident.Instrument cluster

298 2-4. Using other driving systems
■Sounds and vibrations caused by the ABS, brake assist, VSC and
TRAC
● A sound may be heard from the engine compartment when the hybrid
system is started, just after the vehicle begins to move, if the brake pedal
is depressed forcefully or repeatedly, or 1-2 minutes after the hybrid sys-
tem is stopped. 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.
■ EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may
be heard. This does not indicate a malfunction.
■ Reduced effectiveness of the EPS system
The effectiveness of the EPS system 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 EPS system should return to normal within 10 minutes.
■ Electric power steering system warning light (warning buzzer)
P. 501

370 3-5. Other interior features
CAUTION
■Burns
●Use caution when seating the following persons in a seat with the seat
heater on to avoid the possibility of burns:
• Babies, small children, the elderly, the sick and the physically chal-
lenged
• Persons with sensitive skin
• Persons who are fatigued
• Persons who have taken alcohol or drugs that induce sleep (sleeping drugs, cold remedies, etc.)
● Do not cover the seat with anything when using the seat heater.
Using the seat heater with a blanket or cushion increases the temperature
of the seat and may lead to overheating.
● Do not use the seat heater more than necessary. Doing so may cause
minor burns or overheating.
NOTICE
■To prevent seat heater damage
Do not put heavy objects that have an uneven surface on the seat and do
not stick sharp objects (needles, nails, etc.) into the seat.
■ To prevent 12-volt battery discharge
Turn the seat heaters off when the hybrid system is off.

5
When trouble arises
549
5-2. Steps to take in an emergency
If your vehicle overheats
Correction procedures■ If the high coolant temperature warning light flashes or comes
on
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 flashes or comes on:
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.
STEP 1
STEP 2

552 5-2. Steps to take in an emergency
If necessary, add power control
unit coolant up to the “F” line.
Water can be used in an emer-
gency measure if power control
unit coolant is unavailable.
(P. 566)
Have the vehicle checked at nearest Toyota dealer as soon as possi-
ble.
STEP 5
■ Overheating
The following symptoms may occur when your vehicle is overheating:
●Hybrid system output decrease
● Steam is coming from under the hood