2010 TOYOTA PRIUS coolant

474 4-3. Do-it-yourself maintenance
PRIUS_U (OM47668U) U.S.A.
Replacing light bulbs■ Headlight low beams (halogen bulbs)
For the right side only: 
Remove the bolt and unclip the
engine coolant reservoir hose.
Then lift up the air cleaner inlet
duct.
Turn the bulb base counterclock-
wise.
STEP1
ITO43P162
STEP2

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

550 5-2. Steps to take in an emergency
PRIUS_U (OM47668U) U.S.A.■
If “HYBRID SYSTEM OVERHEAT” is shown on the multi-infor-
mation display
Stop the vehicle in a safe place and turn off the air condition-
ing system.
Leave the hybrid system operating and carefully lift the hood.
Check if the cooling fans are operating.
If the fans are operating: 
Wait until “HYBRID SYSTEM OVERHEAT” disappears and
then stop the hybrid system. 
If the message does not disapp ear, call your Toyota dealer.
If the fans are not operating: 
Stop the hybrid system immediately and call your Toyota
dealer.
After the hybrid system has
cooled down, check the power
control unit coolant level and
inspect the cooling system for
leaks.
STEP1
STEP2
STEP3
STEP4