2008 TOYOTA PRIUS coolant temperature

145
2-2. Instrument cluster
2
When driving
PRIUS_U_(L/O_0802)
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. 456)

359
4-3. Do-it-yourself maintenance
4
Maintenance and care
PRIUS_U_(L/O_0802)
CAUTION
The engine compartment contains many mechanisms and fluids that may
move suddenly, become hot, or become electrically energized. To avoid death
or serious injury.
■
When working on the engine compartment:
● Keep hands, clothing, and tools away from the moving fan and engine
drive belt.
● Be careful not to touch the engine, inverter, radiator, exhaust manifold, etc.
right after driving as they may be hot. Oil and other fluids may also be hot.
● Do not leave anything that may burn easily, such as paper or rags, in the
engine compartment.
● Do not smoke, cause sparks or expose an open flame to fuel or the 12 volt
battery. Fuel and 12 volt battery fumes are flammable.
● Be extremely cautious when working on the 12 volt battery. It contains poi-
sonous and corrosive sulfuric acid.
● Never touch, disassemble, remove or replace the high voltage parts,
cables and their connectors. It can cause severe burns or electric shock
that may result in death or serious injury.
● When the hybrid system is operating with the “READY” light on, the engine
may suddenly start in some cases. When you inspect the engine compart-
ment, be sure to turn off the hybrid system.
■ When working near the electric cooling fan or radiator grille
Be sure the “POWER” switch is OFF.
With the “POWER” switch in ON mode, the electric cooling fan may automat-
ically start to run if the air conditioning is on and/or the coolant temperature
is high. ( P. 373)
■ Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc. from
getting in the eyes.

5
When trouble arises
423
5-1. Essential information
PRIUS_U_(L/O_0802)
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably
needs adjustment or repair. Contact your Toyota dealer as soon as
possible.
■ Visible symptoms
●Fluid leaks under the vehicle
(Water dripping from the air cond itioning after use is normal.)
● Flat-looking tires or uneven tire wear
● Engine coolant temperature displa y indicates that the temper-
ature is higher than normal. ( P. 146)
■ Audible symptoms
●Changes in exhaust sound
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the hybrid system
■ Operational symptoms
●Engine missing, stumbling or running rough
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one side when driving on a level road
● Loss of brake effectiveness, s pongy feeling, pedal almost
touches the floor

430 5-2. Steps to take in an emergency
PRIUS_U_(L/O_0802)
*1:This warning light is displayed on the touch screen.
*2:Open door warning buzzer:

(U.S.A.)
Engine oil replacement
reminder light
Illuminates for about 3 sec-
onds and then flasher for
about 15 seconds:
Engine oil is scheduled to
be changed. Check and the engine oil,
and change if necessary.
Comes on and remains:
Engine oil should be
changed. Check and change the
engine oil.

*1
Hybrid battery warning
light
The hybrid battery voltage
drops when the transmis-
sion is left in “N” position. Push the “P” position
switch.
The hybrid battery is dis-
charged. If this light comes on with
the “READY” light on in this
case, have the system
checked by your Toyota
dealer.
High coolant temperature
warning light Indicates high engine cool-
ant temperature P. 456
Master warning light A buzzer sounds and the
warning light comes on
and flashes to indicate that
the master warning system
has detected a malfunc-
tion. Take appropriate action in
accordance with the mes-
sage displayed on the multi-
information display.
Warning lightWarning light/DetailsCorrection procedure

456
5-2. Steps to take in an emergency
PRIUS_U_(L/O_0802)
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 engine and carefully lift the hood.
If you do not see steam: Leave the engine running and carefully lift the hood.
Remove the engine compartment cover. ( P. 365)
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 engine.
If the fan is not operating: Stop the hybrid system immediately and call your local Toy-
ota dealer.
After the hybrid system has
cooled down sufficiently, check
the coolant level and inspect the
radiator core (radiator) for any
leaks.
The following may indicate that your vehicle is overheating:
The high engine coolant temperature warning light comes on:
The engine may be overheating.
Follow the correction procedure as described blow.
STEP1
STEP2
STEP3
STEP4
ITY52P018
STEP5

5
When trouble arises
457
5-2. Steps to take in an emergency
PRIUS_U_(L/O_0802)
Add coolant if required.
Water can be used in an emer-
gency measure if coolant is
unavailable. (
P. 467)
Have the vehicle checked at your nearest Toyota dealer as soon as
possible.
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.
CAUTION
■To prevent an accident or injury when inspecting under the hood of
your vehicle
● Keep hands and clothing away from the fan and engine drive belt while the
engine is running.
● Do not loosen the radiator cap while the engine and radiator are hot.
Serious injury, such as burns, may result from hot coolant and steam
released under pressure.

481
6-1. Specifications
6
Vehicle specifications
PRIUS_U_(L/O_0802)
Warning: The temperature grades for this tire are established for a
tire that is properly inflated and not overloaded.
Excessive speed, underinflation, or
excessive loading, either sepa-
rately or in combination, can caus e heat buildup and possible tire fail-
ure.
Glossary of tire terminology
Tire related termMeaning
Cold tire inflation
pressure Tire pressure when the vehicle has been
parked for three hours or more, or has not
been driven more than 1 mile or 1.5 km under
that condition
Maximum inflation
pressure The maximum cold inflated
pressure to which a
tire may be inflated, s hown on the sidewall of
the tire
Recommended
inflation pressure Cold tire inflation pressure recommended by a
manufacturer.
Accessory weight The combined weight (in excess of those stan-
dard items which may be replaced) of trans-
mission, power steering, power brakes, power
windows, power seats, radio and heater, to the
extent that these items
are available as factory-
installed equipment (whether installed or not)
Curb weight The weight of a motor vehicle with standard
equipment, including the maximum capacity of
fuel, oil and coolant, and if so equipped, air
conditioning and additional weight optional
engine
Maximum loaded
vehicle weight The sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight
(d) Production options weight
Normal occupant
weight 150 lb. (68 kg) times the number of occupants
specified in the second column of Table 1
* that
follows

506
PRIUS_U_(L/O_0802)
What to do if...
What to do if...
A tire puncturesP. 438If you have a flat tire
The engine does not start
P. 8 1Hybrid system immobilizer system
P. 448If the engine will not start
P. 451If the 12 volt battery is discharged
The high coolant temperature
warning light comes on.
Steam can be seen coming
from under the hood
P. 456If your vehicle overheats
The key is lostP. 449If you lose your keys
The 12 volt battery runs outP. 451If the 12 volt battery is discharged
The doors cannot be lockedP. 5 1Doors
The horn begins to soundP. 8 4Alarm
The vehicle is stuck in mud or
sandP. 459If the vehicle becomes stuck
The warning light or indicator
light comes onP. 426If the warning light turns on