diagram TOYOTA PRIUS 2001 Service Owner's Guide

2001 PRIUS (EWD414U)
M OVERALL ELECTRICAL WIRING DIAGRAM
11 12
10 9
24 PRIUS (
Cont' d)A
B
C
7C C98C10C11C
5 II1 3 II1 4 II1 2 II1 1 II1
M D
33 33 33
2 1
5 3
1 2
5 3
2 1
5 3
33 33 33
18 IE1 16 IE1 13 B 6B
1IA1 5IA1
IDCo wl s ide
panel LH IECowl side
panel LH
Air Conditioning
C , A 9 A 7 A 8,
A/C AMPLIFIERAB B±R
G±W
G
R±L
P
P± BR±L R±L
P±B
G± R
W W
W
W
W
W BR±WGR±LR Y± B P L±R
R± LG G± WB± R
L±Y
P± B P± BW± B W± B
W±B W±B
W±B
AAA 12345
J 1
JUNCTION
CONNECTORJ11
JUNCTI ON
CONNECTOR S5TPM SGTPM TPM AOF AOD HTRO HTR2BSET TSET MSET PI G5 PSG SW
A/ CSW
F/RSW
RDEFSW
FULL
A/ CPI G LED
A/ CLED
F/RLED
RDE FLED
FULL
A/CHTR3
RE LAYHTR2
REL AYHTR1
REL AY
A1 6
AI R VENT MODE CONTROL S ERVO MOT OR1A 3B 1B
2B 4B 2AP 3 P 4,
P TC HEA TERAB

W 2000 TOYOTA MOTOR CORPORATIONAll rights reserved. This book may not be repro-
duced or copied, in whole or in part, without the
written permission of Toyota Motor Corporation.
First Printing: Apr. 5, 2000 01-000405-00
FOREWORD
To assist you in your sales and service activities, this manual explains the main characteristics of the new PRIUS,
in particular providing a technical explanation of the construction and operation of new mechanisms and new
technology used.
Applicable models: NHW11 series
This manual is divided into 4 sections.
1. Introduction ± Exterior appearance and model code.
2. New Model Outline ± Explanation of the product to give a general understanding of its features.
3. Technical Description ± Technical explanation of the construction and operation of each new system and
component.
4. Appendix ± Major technical specifications of the vehicle.
CAUTION, NOTICE, REFERENCE and NOTE are used in the following ways:
CAUTION
A potentially hazardous situation which could result in injury to people may occur
if instructions on what to do or not do are ignored.
NOTICEDamage to the vehicle or components may occur if instructions on what to do or not
do are ignored.
REFERENCEExplains the theory behind mechanisms and techniques.
NOTENotes or comments not included under the above 3 titles.
For detailed service specifications and repair procedures, refer to the following Repair Manuals:
Manual Name
Pub. No.

2001 PRIUS Repair Manual

2001 PRIUS Electrical Wiring DiagramRM778U
EWD414U
All information contained herein is the most up-to-date at the time of publication. We reserve the right to make
changes without prior notice.

ENGINE ± 1NZ-FXE ENGINE
182EG20
182EG21
From Air Cleaner To Intake Air Chamber
When the Tank is Full
From Air CleanerTo Intake Air Chamber
When the Tank is EmptyVapor Reducing Fuel Tank 60

System Diagram 
Fuel Gauge
A direct-acting fuel gauge has been provided in the sub tank.
This gauge consists of a pipe that is surrounded by a coil, and a float in the pipe moves up and down with
the fluctuation of the fuel level.
A magnet is attached to the back side of the float. The up or down movement of the float causes a change
in the magnetic field. The flow of current through the coil creates a potential difference, and the resultant
voltage is transmitted to the meter ECU. For details, see page 146 (Meter Section).

ENGINE ± 1NZ-FXE ENGINE
182EG22
Circuit
Opening
Relay
VSV
(for
EVAP)
Intake
Air Temp.
SensorThrottle
Position
Sensor
ECMHV
ECU
Accelera-
tor Pedal
Position
Sensor
Cooling
Fan Relay
Throttle
Control
Motor
Igniter
Camshaft Position Sensor
Knock
Sensor
Mass Air
Flow Meter
VSV
(for Toyota
HCAC
System)Vacuum
Sensor
(for Toyota
HCAC
System)
Crankshaft
Position Sensor Injector
Camshaft
Timing
Oil Con-
trol Valve
Engine
Coolant
Te m p .
Sensor
TWC
Heated Oxygen
Sensor (Bank 1,
Sensor 1)
Heated Oxygen
Sensor (Bank 1,
Sensor 2)
Actuator (for HC
Adsorber)
TWC (with HC
Adsorber)
VSV (for Purge Flow
Switching Valve)
Vapor Pressure Sensor
VSV (for Canister Closed Valve)
Charcoal
Canister
Fuel Pump65
3. Engine Control System Diagram

ENGINE ± 1NZ-FXE ENGINE
182EG25
Engine Load
Full Load Performance
Range 4Range 5
Range 3
Range 2
Range 1Engine Speed
TDC
EXIN
BDCLatest
timing
To retard
side
IN
EX
To advance
side
EX IN71
In proportion to the engine speed, intake air volume, throttle position and water temperature, the ECM cal-
culates an optimal valve timing under each driving condition and control the camshaft timing oil control
valve. In addition, ECM uses signal from the camshaft position sensor and the crankshaft position sensor
to detect the actual valve timing, thus performing feedback control to achieve the target valve timing.

Operation During Various Driving Condition (Conceptual Diagram) 
Operation StateRangeValve TimingObjectiveEffect
During Idling1
182EG26
Eliminating overlap to
reduce blow back to the
intake sideStabilized
idling rpm
Better fuel
economy
At Light Load2
182EG27
Decreasing overlap to
eliminate blow back to
the intake sideEnsured
engine
stability
At Medium
load3
182EG28
Increasing overlap to
increase internal EGR for
pumping loss elimination
Better fuel
economy
Improved
emission
control

ENGINE ± 1NZ-FXE ENGINE
182EG31
Accelerator Pedal
Position SensorThrottle Valve
Throttle Position Sensor
Throttle Control
Motor
HV
ECUECM
182EG33 182EG32
Accelerator Pedal
Position Sensor(V)
5.0
4.0
3.0
2.0
1.0
0 10 2030 405060 70 80
125Output Voltage
Accelerator Pedal Depressed AngleVPA2
VPA1 74
8. ETCS-i (Electronic Throttle Control System-intelligent)
General
The ETCS-i, which realizes excellent throttle control in all the operating ranges, has been adopted.
In the conventional throttle body, the throttle valve opening is determined invariably by the amount of
the accelerator pedal effort. In contrast, the ETCS-i used the ECM to calculate the optimal throttle valve
opening that is appropriate for the respective driving condition and uses a throttle control motor to control
the opening.
The ETCS-i controls the ISC (Idle Speed Control) system and the cruise control system.

System Diagram 
Construction
1) Accelerator Pedal Position Sensor
The accelerator pedal position sensor is mounted on the accelerator pedal. To detect the pedal opening
angle, 2 separate systems consisting of main and sub sensors are used, and 2 separate return springs are
used to improve reliability. In the detecting portions, Hall elements have been adopted. Due to the charac-
teristics of the Hall elements, different signals are output depending on whether the pedal is pressed all
the way or is released. To correct these signals, a mechanical device has been provided to detect the cor-
rect pedal opening angle. The sensors of the 2 systems output the same signals.

THS (TOYOTA HYBRID SYSTEM)
Shift Position
Sensor
182TH05
Accelerator
Pedal Position
Sensor
BRAKE
ECU
Shift Position
(Main and Sub)
Accelerator Angle
(Main and Sub)
Regenerative
Request FactorHV ECUInverter
Voltage
SMR Control
MG2MG1
RPMEngine
Power
RequestCharging
Condition,
Amperage
SMRSMR
Amperage
HV
Battery Engine
Planetary Gear
Unit
Wheel
Wheel
ECM
Battery
ECU
Hydraulic
Brake
Actual
Regenerative
Braking Factor
Auxiliary
Battery
Mechanical Power Path
Electrical Signal Hydraulic
Converter
25

SYSTEM DIAGRAM

THS (TOYOTA HYBRID SYSTEM)
182TH26
Inverter
Converter
182TH15
Inverter
HV
Battery
Ignition Signal
Ground
Voltage
Detection
Circuit
Voltage
Detection
Circuit
Bridge Circuit for MG2
Amperage
Sensor
Signal Processor /
Protective Function Processor
Bridge Circuit for MG1
Amperage
Sensor
MG2
HV ECU
MG1
182TH27
Reservoir Tank
Radiator
Water Pump35
INVERTER
1. General
The inverter is an electric power converter that
converts the direct current of the Hybrid vehicle's
high-voltage battery (DC 273.6 V) and the alter-
nating current of the MG1 and MG2.
Consisting of 2 three-phase bridge circuits for
MG1 and MG2, respectively, and each containing
6 power transistors, the inverter converts direct
current and three-phase alternating current. The ac-
tivation of the power transistors is controlled by the
HV ECU. In addition, the inverter transmits in-
formation that is needed for current control, such as
the output amperage or voltage, to the HV ECU.
Together with MG1 and MG2, the inverter is
cooled by the dedicated radiator of the coolant
system that is separate from that of the engine.
2. System Diagram
3. Cooling System
A cooling system via water pump for the inverter
and MG1, 2 has been added.
The HV ECU controls the water pump with cool-
ant temperature.
It is separated with the engine cooling system.

THS (TOYOTA HYBRID SYSTEM)
Battery Voltage for Each
Module
HV Battery Temp. Sensor
Temp. Sensor (Circumference)
Amperage sensor
A / C Signal
Battery ECU
A / C ECU
HV Battery Cooling Fan
HV ECU
Amperage Signal
Total Voltage Signal
Charge or Discharge Signal
DiagnosisData Link Connector 3
182TH11
HV Battery
SMR2
Battery Module
(7.2 V x 19)
Service Plug
High-Voltage Fuse
Battery Module
(7.2 V x 19)
SMR3
Resistor SMR1
38
HV BATTERY CONTROL SYSTEM
DESCRIPTION
To maintain the battery at a proper SOC (state of charge), and to ensure safety in the event that the HV battery
malfunctions, the battery ECU features the following control functions:

System Diagram 
CONSTRUCTION
The HV battery, battery ECU, and SMR (sys-
tem main relay), are enclosed in a single case
and placed in the luggage compartment behind
the rear seat to make more effective use of ve-
hicle space.
In the battery area, six 1.2-volt cells are con-
nected in series to form one module. A total of
38 modules are connected in series.
Thus, the HV battery containing a total of 228
cells has a rated voltage of 273.6 V.
A service plug that shuts off the circuit is pro-
vided in the middle of the 38 modules. Before
servicing any portion of the high-voltage cir-
cuit, make sure to remove the service plug. For
further details, refer to the 2001 Prius Repair
Manual (Pub No. RM778U).

CHASSIS ± BRAKES
182CH44
Front
Brake ActuatorRear
Hydraulic
Brake
Differential
Gear
Stroke
Simulator
Hydraulic
Adjustment Area
ABS Function AreaHydraulic
Brake
MG2
MG1Inverter
EngineHV Battery
THS (TOYOTA Hybrid System) Regenerative
Brake
Switching
Valve
Power Splitting
Device
182CH45
Combination Meter
Brake ECU
Brake Warning Buzzer
Rear Wheel
Speed Sensors
and Rotors
Hydraulic Brake Booster
(Master Cylinder Portion)
Front Wheel Speed
Sensor and Rotor
Brake Actuator HV ECU
Hydraulic Brake
Booster
Power Supply
portion
Solenoid RelayReservoir
Tank
ECMPump
Motor Relays 104
BRAKE SYSTEM
1. General

A brake system, which uses brake fluid that is stored under high pressure to assist the brake pedal effort
and to operate the ABS with EBD control and the regenerative brake cooperative control, has been adopted.

A regenerative brake system, which uses the MG2 that is used for driving the vehicle as a generator to effi-
ciently convert the energy that is created during braking, has been adopted. This system enables to collect
more driving energy by having the control to cooperate the hydraulic brake and the regenerative brake.
2. System Diagram
3. Layout of Main Components