2010 TOYOTA PRIUS engine coolant

476 4-3. Do-it-yourself maintenance
PRIUS_U (OM47668U) U.S.A.■
Headlight high beams
For the right side only: Remove the bolt and unclip the engine
coolant reservoir hose. Then lift up the air cleaner inlet duct.
( P. 474)
Turn the bulb base counterclockwise.
Vehicles with LED headlights
Vehicles with halogen headlights
Unplug the connector while
pushing the lock release.
STEP1
STEP2
ITO43P185
ITO43P164
ITO43P165
STEP3

477
4-3. Do-it-yourself maintenance
4
Maintenance and care
PRIUS_U (OM47668U) U.S.A.
■
Parking lights
For the right side only: Remove the bolt and unclip the engine
coolant reservoir hose. Then lift up the air cleaner inlet duct.
( P. 474)
Turn the bulb base counterclockwise.
Vehicles with LED headlights
Vehicles with halogen headlights
Remove the light bulb.
STEP1
STEP2
ITO43P186
ITO43P166
ITO43P167
STEP3

478 4-3. Do-it-yourself maintenance
PRIUS_U (OM47668U) U.S.A.■
Front side marker lights
For the right side only: Remove the bolt and unclip the engine
coolant reservoir hose. Then lift up the air cleaner inlet duct.
( P. 474)
Turn the bulb base counterclockwise.
Vehicles with LED headlights
Vehicles with halogen headlights
Remove the light bulb.
STEP1
STEP2
ITO43P187
ITO43P167
STEP3

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

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

5
When trouble arises
549
5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
Check to see if the cooling fans are operating.
If the fans are operating: 
Wait until the high coolant temperature warning light goes
off and then stop the hybrid system.
If the fans are not operating:  Stop the hybrid system immedi ately and call your local
Toyota dealer.
After the hybrid system has
cooled down sufficiently, check
the engine coolant level and
inspect the radiator core (radia-
tor) for any leaks.
If necessary, add engine coolant
up to the “FULL” line.
Water can be used in an emer-
gency measure if engine coolant
is unavailable. (P. 562)
STEP3
STEP4
ITO52P130
STEP5

552 5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.
CAUTION
■To prevent an accident or injury when inspecting under the hood of
your vehicle
● If steam is seen coming from under the hood, do not open the hood until
the steam has subsided. The engine compartment may be very hot, caus-
ing serious injury such as burns.
● With a hybrid vehicle, there are times when the gasoline engine automati-
cally starts to run or the cooling fans suddenly start to operate. Do not
touch or approach the rotating parts of the belt or fans. Doing so may lead
to fingers, clothes or tools getting caught, resulting in an accidental injury.
● Do not loosen the coolant reservoir cap while the hybrid system and radia-
tor are hot. 
Serious injury, such as burns, may result from hot coolant and steam
released under pressure.
NOTICE
■ When adding engine/power control unit coolant
Wait until the hybrid system has cooled down before adding engine/power
control unit coolant. 
When adding coolant, do so slowly. Adding cool coolant to a hot hybrid sys-
tem too quickly can cause damage to the hybrid system.

562 6-1. Specifications
PRIUS_U (OM47668U) U.S.A.
Cooling system
Ignition system
Capacity
Gasoline engine
With an exhaust
heat recovery sys-
tem
Without exhaust
heat recovery sys-
tem
Power control unit7.6 qt. (7.2 L, 6.3 Imp.qt.)
6.9 qt. (6.5 L, 5.7 Imp.qt.)
2.1 qt. (2.0 L, 1.8 Imp.qt.)
Coolant type
Use either of the following:
• “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-based non-silicate, non-amine, non-nitrite, and non-borate
coolant with long-life hybrid organic acid technol-
ogy
Do not use plain water alone.
Spark plug
Make DENSO SC20HR11
Gap 0.043 in. (1.1 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust gap when tuning engine.