2001 TOYOTA PRIUS display

NEW MODEL OUTLINE
MAIN EQUIPMENT
182MO20
[Information Screen]
This screen indicates the direction of energy trans-
mission. It is also possible to check the current drive
method (engine, motor or both) and status of power
generation by the engine and that of charging regen-
erative energy.
This screen indicates the average fuel consumption,
amount of recovered energy and fuel consumption for
that moment. Average fuel consumption is displayed
at 5-minutes intervals. The recovered energy display
indicates the amount of energy recovered over the past
5 minutes, with each mark representing 50Wh.
182BE36
182BE37
17
A range of features for comfort - the more you use them,
the better they get.
Multi-Information Display

The 5.8º wide touch panel type multi-information color LCD
is standard.

Energy monitor, fuel consumption and other vehicle information
screens, audio operation status and audio operation screen can
be indicated on the multi-information display. The outside tem-
perature are also indicated on the screen.
[Audio system]

An AM/FM cassette and 4-speaker system compatible with the
multi-information display has been adopted.

As the touch panel type display is used to operate the audio sys-
tem, the multi-information display simultaneously indicates the
operating status of the audio system.

The antenna provided is a collapsible style pole antenna posi-
tioned at the center of the roof.
[GPS Voice Navigation]

A GPS (Global Positioning System) voice navigation system
is optional.

The multi-information display can show the map on favorite
type among turn list, arrow display and enlarged intersection.

Using DVD (Digital Versatile Disk) as a memory source for map
data, a large quantity of information can be processed.
 Main Function of the Multi-information Display
ScreenFunction
Enlargement / reduction, rotation and move-
ment of map
Mapscreen
Indication of current position and direction of
travel
Map screen
displayCorrection of current positiondis lay(option)Setting, change and indication of route()
Voice guidance
Indication of enlarged intersections
Memory and indication of map position
Audio screenStatus of audio equipment and audio opera-
tion screen indication
InformationEnergy monitor screen indicationInformationscreenFuel consumption screen indication
Adj t tSound quality adjustment screen indicationAdjustmentscreenImage quality adjustment screen indicationscreenNo indication
On-screenAudio status indicationOn screenindicationWarning indication
Interrupt screenWarning indication
DiagnosisscreenDisplays system diagnosisscreen
displayDisplays various types of coefficient settings

ENGINE ± 1NZ-FXE ENGINE
ECM
EFI MAIN RELAY BATTERY+B BATT, BM
HTE
ETH
SPHV
ESTP
GO HV ECU
(Hybrid Vehicle Control ECU)
VACUUM SENSOR
(for TOYOTA HCAC SYSTEM)ACCELERATOR PEDAL
POSITION SENSORHCLS
VAPOR PRESSURE SENSORPTNK VPA 1, 2
DATA LINK CONNECTOR 3SIL
TC
AIR CONDITIONING ECU AIR CONDITIONING CUT-
OFF CONTROL
ACT
COOLING FAN RELAYCOOLING FAN
CONTROLFA N
VSV (for EVAP) EVAP CONTROLEVP1
VSV (for CANISTER
CLOSED VALVE) CCV
VSV (for PURGE FLOW
SWITCHING VALVE)TBP
METER ECU
AIR CONDITIONING ECU
DISPLAY ECU
BODY ECU
VSV
(for TOYOTA HCAC SYSTEM)
EFI MAIN RELAY
MALFUNCTION INDICATOR
LAMP MPX1
NEO
MPX2
HCC
MREL
W
64

THS (TOYOTA HYBRID SYSTEM)
182TH33
31
± REFERENCE ±
The MG1 and the MG2 are generally shut down when the shift lever is in the N position.
However, the shut-down function is canceled under the following exceptions:

During driving, if the brake pedal is depressed and a wheel locks up, the ABS is activated. After this, low
torque is requested from the MG2 to provide supplemental power in order to restart the rotation of the wheel.
Even if the shift lever is in the N position at this time, the shut-down function is canceled to allow the wheel
to rotate. After the wheel rotation has been restarted, the system resumes its shut-down function.

When the vehicle is driven in the D or B position and the brake pedal is depressed, the regenerative brake
operates. At this time, as the driver moves the shift lever to the N position, the brake hydraulic pressure in-
creases while the request torque of the regenerative brake decreases gradually so as not to create a sluggish
brake feel. After this, the system effects its shut-down function.
When any of the conditions described below is pres-
ent, the message prompt as shown appears in the
multi information display, accompanied by the illu-
mination of the master warning light and the continu-
ous sounding of the buzzer.

The ªREADYº light is illuminated, the shift lever
is in the N position, and the HV battery is dis-
charged.

The ªREADYº light is illuminated, the shift lever
is in the N position, and the driver's door is open.

The ªREADYº light is illuminated, the parking brake is engaged, the shift lever is in the B or D position, and
the driver's door is open.

THS (TOYOTA HYBRID SYSTEM)
182TH22
1. READY Light
2. Output Control
Warning Light 3. Master Warning Light
4. Malfunction Indicator light 5. Discharge Warning Light
6. EMPS Malfunction
Warning Light7. HV Battery Warning Light
8. Hybrid System
Malfunction Warning
Light 32
INDICATOR AND WARNING LIGHT
The warning lights of the Prius are different from those on conventional vehicles. Inspection and repair
should be performed while referring to the troubleshooting section in the 2001 Prius repair manual
(RM778U).

Center Meter 
Multi Information Display 
1. READY lightTurns on when the ignition switch is turned to START to indicate that the ve-
hicle is ready to drive.
2. Output control
warning lightTurns on when the remaining HV battery charge becomes insufficient at R
range or when there is an abnormal temperature rise in the HV battery due
to continuous driving under heavy loads. It may also light when the HV bat-
tery temperature is low (after starting at low temperatures). The hybrid sys-
tem output is limited while this light is on.
Travel at reduced speeds (avoid sudden acceleration) while the light is lit.
3. Master warning
lightTurns on with buzzer sounding by linked operation with warning lights ª6º
to ª8º on the multi center display.
4. Malfunction
indicator lightTurns on when there is a malfunction in the engine control system.
5. Discharge warning
lightTurns on when there is a malfunction in the 12 V charging system (converter
assembly).
If it turns on together with the master warning light and hybrid system
warning light, check the diagnostic code.
6. EMPS malfunction
warning lightTurns on when there is a malfunction in the EMPS control system.
7. HV battery warning
lightTurns on when the HV battery is discharged to the lower limit.
8. Hybrid system
warning lightTurns on when a malfunction in MG1, 2, inverter, HV battery or HV ECU
is detected.

CHASSIS ± STEERING
182CH68
Rear Wheel
Speed SensorsBrake ECU
Torque Sensor Signal 1
Torque Sensor Signal 2
EMPS
ECUMeter ECU
Gateway ECUDLC3
Display ECU
Multi-information
Display
123
EMPS (Electric Motor-assisted Power Steering)
1. General
In accordance with sensor information such as that provided by the rear wheel speed sensors, the torque sen-
sor that is mounted on the steering gear, and the EMPS ECU determines the direction and the force of the
power assist and actuates the DC motor that is mounted on the steering gear to provide power assist to the
steering effort.
The EMPS in the Prius the following features:
This system can provide power assist even when the engine is stopped.
This system offers excellent fuel economy characteristics because power assist is provided by the DC mo-
tor that is mounted on the steering gear, and this motor consumes energy only when power assist is re-
quired.
Unlike the conventional hydraulic power steering system, this system excels in serviceability because it
does not require pipes or the power steering fluid.

System Diagram 

CHASSIS ± STEERING
182CH69
Meter ECU
EMPS ECU
Relay
DC MotorRear Wheel Speed
Sensors and Rotors
Brake ECU Multi-information Display 124
2. Layout of Main Components
3. Function of Main Components
ComponentsFunction
St i
Torque Sensor
Detects the twist of the torsion bar, converts the torque that is applied
to the torsion bar into an electrical signal, and outputs this signal to
the ECU.
Steering
Gear
DC MotorGenerates power assist in accordance with a signal received from the
EMPS ECU.
Reduction
MechanismReduces the rotation of the DC motor and transmits it to the pinion
shaft.
EMPS ECU
Actuates the DC motor mounted on the steering gear for providing
power assist, based on the signals received from various sensors and
the rear wheel speed signal.
Meter ECUOutputs a signal for displaying the PS warning on the center display
in case of a malfunction in the system.
Brake ECURear wheel speed signals are outputted to EMPS ECU.
RelaySupplies power to the DC motor for power assist.
Multi-information DisplayDisplays the PS warning in case of a malfunction in the system.

BODY ELECTRICAL
BODY ELECTRICAL ± BATTERY AND MULTIPLEX COMMUNICATION SYSTEM
182BE01
: BEAN : UART
: AVC-LAN : Serial Data
Link
Brake ECU
HV ECU
Air Condi-
tioning ECU
Meter ECU
ECM
Body ECU
Display ECU
Audio
ComponentsGateway
ECU
Power Window
Master SwitchDoor Con-
trol ReceiverBattery ECU
141
AUXILIARY BATTERY
DESCRIPTION
All the body electrical systems and auxiliary equipment operate using the same 12 V battery used on ordinary
gasoline engine vehicles.
However, as the battery structure is different, Prius uses an exclusive battery. See page 42 in the THS (TOYOTA
Hybrid System) section for details of the auxiliary battery structure.
MULTIPLEX COMMUNICATION SYSTEM
DESCRIPTION
A multiplex communication system has been adopted for body electrical system control and to achieve
a slimmer wiring harnesses configuration.
BEAN (Body Electronics Area Network) has been adopted between the body ECU, ECM, meter ECU,
air conditioning ECU, and the gateway ECU. Furthermore, AVC-LAN (Audio Visual Communication-
Local Area Network) has been adopted between the display ECU and the audio components.
The conversion of communication signals between BEAN and AVC-LAN is performed by the gateway
ECU.
UART (Universal Asynchronous Receiver Transmitter), which performs unidirectional communication,
has been adopted between the body ECU and the power window master switch.
A serial data link has been adopted between the body ECU and the door control receiver. In addition, a
serial data link has been adopted between the ECM, HV ECU, brake ECU, and the battery ECU, which
pertain to the control of the hybrid system.

System Diagram 

BODY ELECTRICAL ± MULTIPLEX COMMUNICATION SYSTEM 142
SYSTEM OPERATION
1. General
The ECUs that pertain to the body electrical system perform the functions and system controls described be-
low.
Gateway ECU
Conversion of data between AVC-LAN and BEAN
Transmission of vehicle information to the display ECU, in order for it to be displayed on multi-informa-
tion display
Body ECU
Power window system control (Front, Rear passenger only)
Door lock control system control
Wireless door lock remote control system control
Theft deferrent system control
Daytime running light system control
Illuminated entry system control
Light auto turn-off system control
Seat belt warning system control
Key reminder system control
Diagnosis
Meter ECU
Meter control
Illumination and flashing control of indicator and warning lights
Sounding control of warning buzzer
Air Conditioning ECU
Air Conditioning control
ECM
Engine control
Diagnosis
Display ECU
Transmission and reception associated with audio and visual functions