ECU TOYOTA PRIUS 2001 Service Repair Manual

2001 PRIUS (EWD414U)
M OVERALL ELECTRICAL WIRING DIAGRAM
1
234
24 PRIUS(
Cont. next page)
2ACC
IG1
ST1 AM1 4
1
120A MAIN
1B 1A
1D2H 1
30A HTR2
2 1
3 52B 3 2D 6
IDCowl side
panel LH 2K 8
33
A
W±GW
B
B± G
W± G
J11
JUNCTI ON
CONNECTOR
100A DC/DCBATTERYF18
FUSI BLE L I NK
BLOCK NO. 2F10 F11,
FUSIBLE LINK
BL OCK NO. 1ABF13, DIG1
RE LAY
1B 32 1
3 5
4
2 1
3 5
1K 81J13 1A51F31K3 1F 410A
HTR2C 5
2D 3 82G
10A GAUGE 7. 5A ECU±B
W 50A HTR
B±Y
30A HTR1
3
50A HTR3
3
WA
B
C
AA AA
AB
2 1
M
A
IECowl si de
panel LH
W±B
J 1
JUNCTI ON
CONNECTOR3A 11B 3B
21 IE1 15 IE1 20 IE1
3
2 1
5 3 3
3 3
1 2
M1A
CA CA
AB
13 IE110 B
8IE1E
7A
AB
AAD
8A
F
Air Conditioning
123
AA4
B
BF 2
222
11
5A AM1
4
A1BFB± R
G±W
G
R±L
L±O
B±L
W± BL
L±RW±B R
L±YLG±R
V R
G
G± W
B± RB±W B± RB±RV
B± R L±OB±L LG±RR W± B W± BW± B W± B R R
R LG±RV L±YR L±R
R± G R± GL±Y L±R
RA 7 A 8,
A/ C AMPLI FI ERAB
11
R± L
HTR
RELA YCLR MG
RELAY
J 2 J 3,
JUNCTI ON
CONNECTORAB
B 6
BL OWER
MOT OR
B 7
BLOWER MOTOR
L I NEA R CONTROL LER
AJ 7
JUNCTION
CONNECTORMGC BL W PS W I G WP+B
A 3
A / C DUAL
PRESSURE SW J 6
JUNCTI ON
CONNECTOR
W 2
WATER PUMP
MOTOR (
A/C)
R
J22 J23,
JUNCTI ON
CONNECTORABJ27
JUNCTI ON
CONNECTOR
C , A 9
W± B W± BGND
JUNCT I ON CONNECTORB A J24 J25,
W±B R
2D 8W± B
A/ C W/ P
REL AY
A
AJ 6
JUNCTION
CONNECTOR
V I15
IGNITION
SW
Power Source
GND VM +B SI

2001 PRIUS (EWD414U)
M
78
6 5
(
Cont. next page)
24 PRIUS (
Cont' d)
9B 18B
4IE1 5IE1
4IK1 5IK1 A
B
C
EA
B
C
2F 615 A 16 A
11 A 4 A 5 B4B13 D 14 D 23 C
3D 22D 18BIA25
1 2
F2B 6C 5C17 C 15 C 16 C 14 C 13 C
6 II1 8 II1 7 II1 9 II1 10 II1
M 20 C C18 19 C 22 C 21 C
M DD
Air Conditioning
B A
A/ C AMPLI FI ER, A 8 A 7 A 9, C4C 1B 3C 1C 2C2 1
1 2 18
34
1 211
1422
12345 12345 B±R
G±W
G
R±L
L±O
B± LGR± LW±G
BRW±G
BR± WB± R
G±W
G
R±L
GR± B GRGR± BLG P±G R±WW
W W W
W± L BR±W
W± L BR±W
W±L BR± W V± YW W W W
W
W
W W W
W
W
W
W± R BR±YY±RL BR±R
B 8
BODY ECUA
E 8 E 9,
ENGI NE CONTROL MODULEBC
A10
A/ C ROOM
TEMP. SENSOR A12
A/ C THERMI STOR
Fr om FAN NO. 1 and
FA N NO. 2 Rel ay< 22± 4>
LOCK SGLOCK CF S5TS TS SGTPI S5 TPI TPI AI F AI R S5 TP SGTP TP AMC AMHMP X+ MP2 + NE A CTRF TR SGTR TE SGTE
A 2
A/C MAGNETIC
CLUTCH AND
L OCK SENSORMP X+ MPD2 MPX 1 MPX 2 TA M
MP X± MPD1 NEO A CT E 2
GR
, DE10 A 6
AMBI ENT
TEMP.
SENSOR
A11
A/C SOLAR
SENSOR C11
COMBINATION
METE RG 1
GATE WAY
ECU
IK12
Fr om FAN NO. 3 Rel ay
< 22±4>
A1 5
AI R MI X CONTROL SE RVO MOTOR A1 4
AI R I NLE T CONTROL S ERVO MOTOR IDH
Y
10 A
Fr om Conv erter
< 1±13>
MP X+ MPX ± HRLY

NEW MODEL OUTLINE
MAIN EQUIPMENT
182MO23(For U.S.A.)
Glove box Accesory box Multi-box
Front door pocket
Seat back pocket
(Driver's and
passenger seat)
182MO24182MO09
182MO25
Small storage box
Cup holder
(for two caps use)11.839ft3 (by SAE suitcase method)
luggage space is secured.182MO26182MO27182MO28
18
Air Conditioning
An automatic air conditioning has been adopted
in consideration to ease of use.

A clean air filter which removes pollen and
dust is included as a standard fitting for puri-
fying the air inside the cab.

Two air conditioning modes, A/C for eco-
nomical air conditioning and MAX for espe-
cially strong air conditioning, are provided.
Wireless Door Lock Remote Control System
With the wireless door lock remote control system, all the doors can be locked and unlocked by signals emitted
by the transmitter.
Power Window System
A power window system which enables all windows to be raised or lowered with switches has been adopted.
An auto up/down function and jam protection function have been added to the driver's power window.
HV Immobiliser System
HV immobiliser system will not allow the HV system to be started by duplicate key is used. This system
will permit the HV system to be started only when the ID code of the transponder chip impregnated in the
key matches the ID code registered beforehand in the transponder key amplifier.
Theft Deterrent System
When an attempt is made to forcibly enter the vehicle or open the hood or trunk lid without a key, or when
the battery terminals are removed and reconnected, this system sounds the horn and flashes the headlights,
taillights and emergency flashers for about 1 minute to alert the owner. At the same time, it locks all the
doors.
Storage Space
Ample storage space with an emphasis on practicality provided throughout the Prius.
Instrument panel (passenger seat)Seat back pocketFront door pocket
Center console boxLuggage space

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
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

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
182EG39
Front Airbag
Sensors
(RH and LH)Airbag
Sensor
AssemblyHV
ECUCircuit
Opening
Relay
Fuel Pump
Motor ECM73
7. Fuel Pump Control
A fuel cut control is adopted to stop the fuel pump when the SRS airbag is deployed, thus helping reduce fuel
leakage.
In this system, the airbag deployment signal from the airbag sensor assembly is detected by the HV ECU,
send the signal to ECM, which turns OFF the circuit opening relay.
After the fuel cut control has been activated, turning the ignition switch from OFF to ON cancels the fuel cut
control, thus engine can be restarted.

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.

ENGINE ± 1NZ-FXE ENGINE 78
Operation
Initially, the VSV (for canister closed valve) is closed, and the VSV (for EVAP) is open, enabling the VSV
(for purge flow switching valve) to keep the passage between the charcoal canister and the purge line open.
This causes a vacuum to be applied to the purge line, evaporator line, recirculation line, and the line from
the charcoal canister to the fuel tank.
Next, the VSV (for EVAP) is closed in order to maintain a vacuum from the VSV (for EVAP) to the inside
of the fuel tank. Then, any subsequent changes in the pressure are monitored by the vapor pressure sensor
in order to check for evaporative emission leaks.
Next, the VSV (for canister closed valve) and the VSV (for EVAP) open, enabling the VSV (for purge flow
switching valve) to keep the passage between the fuel tank and the purge line open. Then, the air in the fuel
tank is drawn in by the vacuum of the intake chamber, and the density of HC in the exhaust gases is measured
by the oxygen sensor to detect any leaks.
If a leak is detected, the malfunction indicator lamp (MIL) illuminates to inform the driver. Also, the diag-
nostic trouble code (DTC) can be accessed through the use of a hand-held tester.
For details on the DTCs, refer to the 2001 Prius Repair Manual (Pub. No.RM778U).
10. HV Immobiliser System
The HV immobiliser system has been designed to prevent the vehicle from being stolen. This system uses
a HV ECU that stores the ID code of the authorized ignition key. If an attempt is made to start the HV system
using an unauthorized key, the HV ECU prohibit fuel delivery, ignition, and starting the HD system effective-
ly disabling the engine.
For details see page 184 in the HV Immobiliser System section.
11. Diagnosis System
The diagnostic trouble codes can be output via DLC3 to an OBD-II scan tool or a hand-held tester. For details,
refer to the 2001 Prius Repair Manual (Pub. No.RM778U).

THS (TOYOTA HYBRID SYSTEM)
182TH19
EngineECMHV ECU
Shift Position Sensor
Brake ECU
HV Battery
Accelerator Pedal Position Sensor
Hybrid Transaxle Inverter with Converter
Battery ECU
SMR (System Main Relay)
Service Plug23

FEATURES OF THS
This system controls the following modes in order to achieve the most efficient operations to match the driv-
ing conditions:
1. Supply of electrical power from the HV battery to MG2 provides force to drive the wheels
2. While the tires are driven by the engine via the planetary gears, MG1 is driven via the planetary gears to
supply electricity to MG2 to drive the wheels
3. When the vehicle is decelerating, kinetic energy from the wheels is recovered and converted into electrical
energy and used to recharge the HV battery by means of MG2.
The HV ECU switches between these modes (1, 2, 1 + 2, or 3) according to the driving conditions. However,
when the SOC of the HV battery is low, the HV battery is charged by the engine by turning MG1.
As a result, it achieves far greater the fuel economy compared to conventional gasoline engine vehicles, at
a reduced level of exhaust gas emissions. Furthermore, this revolutionary powertrain has eliminated the
constraints that are associated with electric vehicles (such as their short cruising range or their reliance on
external recharging units).

LAYOUT OF MAIN COMPONENTS