2020 TOYOTA PRIUS PLUG-IN HYBRID engine

6497-3. Do-it-yourself maintenance
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
7
Maintenance and care
WARNING
■ When adding washer fluid
Do not add washer fluid when the hybrid system is hot or operating as
washer fluid contains alcohol and may catch fire if spilled on the engine etc.
NOTICE
■ Do not use any fluid other than washer fluid
Do not use soapy water or engine antifreeze instead of washer fluid.
Doing so may cause streaking on the vehicle’s painted surfaces, as well as
damaging the pump leading to problems of the washer fluid not spraying.
■ Diluting washer fluid
Dilute washer fluid with water as necessary.
Refer to the freezing temperatures list ed on the label of the washer fluid bot-
tle.

6917-3. Do-it-yourself maintenance
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
7
Maintenance and care
Checking and replacing fuses
Turn the power switch off.
Confirm that the charging connector is not connected. Also, do not use the
Remote Air Conditioning System during the procedure.
Open the fuse box cover.
Engine compartment type A fuse box
While pushing the 2 claws, lift
up the cover.
When closing the cover, make
sure to attach the 2 claws.
Engine compartment type B fuse box
While pushing the 3 claws, lift
up the cover.
When closing the cover, make
sure to attach the 3 claws.
If any of the electrical components do not operate, a fuse may
have blown. If this happens, check and replace the fuses as nec-
essary.
1
2

7138-2. Steps to take in an emergency
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
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When trouble arises
If you think something is wrong
● Fluid leaks under the vehicle
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● High coolant temperature warning light flashes or comes on
● 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
● Engine missing, stumbling or running roughly
● 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, spongy feeling, pedal almost touches
the floor
If you notice any of the following symptoms, your vehicle proba-
bly needs adjustment or repair. Contact any authorized Toyota
retailer or Toyota authorized repairer, or any reliable repairer as
soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

7158-2. Steps to take in an emergency
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
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When trouble arises
Low engine oil pressure warning light
(warning buzzer)*2
Indicates that the engine oil pressure is too low
 Immediately stop the vehicle in a safe place and con-
tact any authorized Toyota retailer or Toyota autho-
rized repairer, or any reliable repairer.
Malfunction indicator lamp
Indicates a malfunction in:
• The hybrid system;
• The electronic engine control system; or
• The electronic throttle control system
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
SRS warning light
Indicates a malfunction in:
• The SRS airbag system; or
• The seat belt pretensioner system
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
ABS warning light
Indicates a malfunction in:
• The ABS; or
• The brake assist system
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
(Red/yellow)
Electric power steering system warning light (warning
buzzer)
Indicates a malfunction in the EPS (Electric Power Steer-
ing) system
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
Warning lightWarning light/Details/Actions

7168-2. Steps to take in an emergency
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
(Flashes or illuminates)
PCS warning light
• When a buzzer sounds simultaneously:
Indicates a malfunction has occurred in the PCS (Pre-
Collision System).
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
• When a buzzer does not sound:
The PCS (Pre-Collision System) has become temporar-
ily unavailable, corrective action may be necessary.
 Follow the instructions displayed on the multi-infor-
mation display. ( P. 416, 723)
If the PCS (Pre-Collision System) or VSC (Vehicle Stability
Control) system is disabled, the PCS warning light will illu-
minate.
 P. 428
(Orange)
LTA indicator (warning buzzer)
Indicates a malfunction in the LTA (Lane Tracing Assist)
 Follow the instructions displayed on the multi-infor-
mation display. ( P. 444)
Slip indicator light
Indicates a malfunction in:
• The VSC system;
• The TRC system; or
• The hill-start assist control system
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
The light will flash when the ABS, VSC or TRC system is
operating.
High coolant temperature warning light
• When the light flashes:
Indicates that the engine coolant temperature is too high
The light changes from a flashing to a solid light when
the temperature further increases
 Immediately stop the vehicle in a safe place.
( P. 761)
• When the light comes on without flashing:
Indicates a malfunction in the exhaust heat recirculator
system
 Have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable
repairer immediately.
Warning lightWarning light/Details/Actions

7208-2. Steps to take in an emergency
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
*1: Brake system warning buzzer:
When there is a possible problem that could affect braking performance,
the warning light will come on and a warning buzzer will sound.
*2: Low engine oil pressure warning buzzer:
A buzzer also sounds continuously for approximately 30 seconds at maxi-
mum in addition to the low engine oil pressure warning light when the
“READY” indicator is illuminated.
*3: Open door warning buzzer:
The open door warning buzzer sounds to alert one or more of the doors is
not fully closed (with the vehicle having reached a speed of 5 km/h
[3 mph]).
*4: Driver’s and front passenger’s seat belt warning buzzer:
The driver’s and front passenger’s seat belt warning buzzer sounds to alert
the driver and front passenger that his or her seat belt is not fastened. If
the seat belt is unfastened, the buzzer sounds intermittently for a certain
period of time after the vehicle reaches a certain speed.
*5: Rear passengers’ seat belt warning buzzer:
The rear passengers’ seat belt warning buzzer sounds to alert the rear
passenger that his or her seat belt is not fastened. If the seat belt is unfas-
tened, the buzzer sounds intermittently for a certain period of time, after
the seat belt is fastened and unfastened and the vehicle reaches a certain
speed.
*6: This symbol is displayed on the multi-information display.
■ Front passenger detection sensor, seat belt reminder and warning
buzzer
● If luggage is placed on the front passenger seat, the front passenger detec-
tion sensor may cause the warning light to flash and the warning buzzer to
sound even if a passenger is not sitting in the seat.
● If a cushion is placed on the seat, the sensor may not detect a passenger,
and the warning light may not operate properly.
■ Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insufficient or the voltage tempo-
rarily drops, the electric power steering system warning light may come on
and the warning buzzer may sound.
■ If the malfunction indicator lamp comes on while driving
The malfunction indicator lamp will come on if the fuel tank becomes com-
pletely empty. If the fuel tank is empt y, refuel the vehicle immediately. The
malfunction indicator lamp will go off after several trips.
If the malfunction indicator lamp does not go off, contact any authorized
Toyota retailer or Toyota authorized repai rer, or any reliable repairer as soon
as possible.

7268-2. Steps to take in an emergency
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
●If a message or image about an open/close state of a part or replenishment
of a consumable is shown
Confirm the part indicated by the multi-information display or a warning light,
and then perform the coping method such as closing the open door or
replenishing a consumable.
■ If “See Owner’s Manual” is shown
● If “Braking Power Low Stop in a Safe Place See Owner’s Manual” is shown,
this may be a malfunction. Immediately stop the vehicle in a safe place and
contact any authorized Toyota retailer or Toyota authorized repairer, or any
reliable repairer. Continuing to drive the vehicle may be dangerous.
● If “Engine Oil Pressure Low” is shown, this may be a malfunction. Immedi-
ately stop the vehicle in a safe place and contact any authorized Toyota
retailer or Toyota authorized repairer, or any reliable repairer.
● If the following messages are shown, there may be a malfunction. Immedi-
ately have the vehicle inspected by any authorized Toyota retailer or Toyota
authorized repairer, or any reliable repairer.
• “Plug-in charging system malfunction.”
• “Hybrid System Malfunction”
• “Check Engine”
• “Hybrid Battery System Malfunction”
• “Accelerator System Malfunction”
• “Smart Entry & Start System Malfunction See Owner’s Manual”
● If “Exhaust Filter Full See Owner’s Manual” is shown on the multi-informa-
tion display is shown, follow the instruction. ( P. 5 5 8 )
■ If “Shift System Not Active Apply Parking Brake Securely While Parking
See Owner’s Manual” is shown
Indicates a temporary operation failure or malfunction in the shift control sys-
tem. Immediately have the vehicle inspected by any authorized Toyota
retailer or Toyota authorized repairer, or any reliable repairer.
When the message is shown, the hybrid system may not be started or the
shift position may not be changed normally. (Coping method: P. 729)
■ If “Shift System Malfunction Apply Parking Brake Securely While Park-
ing See Owner’s Manual” is shown
Indicates a malfunction in the shift control system. Immediately have the vehi-
cle inspected by any authorized Toyota retailer or Toyota authorized repairer,
or any reliable repairer.
When the message is shown, the hybrid system may not be started or the
shift position may not be changed normally. (Coping method: P. 729)

7298-2. Steps to take in an emergency
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
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When trouble arises
■ If “Engine Oil Level Low Add or Replace” is displayed
The engine oil level may be low. Check the level of the engine oil, and add
engine oil if necessary. This message may be displayed if the vehicle is
stopped on a slope. Move the vehicle to a level surface and check if the mes-
sage disappears.
■ If “Accelerator and Brake Pedals Pressed Simultaneously” is shown
The accelerator and brake pedals are being depressed simultaneously.
( P. 360)
Release the accelerator pedal and depress the brake pedal.
■ If a message that indicates the malfunction of front camera is displayed
The following systems may be suspended until the problem shown in the
message is resolved. ( P. 416, 714)
● PCS (Pre-Collision System)
● LTA (Lane Tracing Assist)
● AHS (Adaptive High-beam System)
● RSA (Road Sign Assist)
● Dynamic radar cruise control with full-speed range
■ If “Radar Cruise Control Unavailable See Owner’s Manual” is shown
The dynamic radar cruise control with full-speed range system is suspended
temporarily or until the problem show n in the message is resolved. (causes
and coping methods: P. 416)
■ If “Radar Cruise Control Unavailable” is shown
The dynamic radar cruise control with full-speed range system cannot be
used temporarily. Use the system when it becomes available again.
■ If the shift position cannot be changed or the power switch is turned to
ACCESSORY mode even if trying to turn the power switch off when a
warning message is shown
If the 12-volt battery is discharged or the shift control system is malfunction-
ing, the followings may occur.
● The shift position may not be changed to P.
When parking, stop the vehicle on level ground and apply the parking brake
firmly.
● The hybrid system may not start.
● The power switch may be turned to ACCESSORY mode even if trying to
turn the power switch off.
In this case, the power switch may be turned off after applying the parking
brake.
● The automatic P position selection function (P. 382) may not operate.
Before turning the power switch off, be sure to press the P position switch
and check that the shift position is in P by the shift position indicator or P
position switch indicator.