Page 69 of 1943

2001 PRIUS (EWD414U)
IO1 6
I 7C 20 B 18
I 7IK1 7IK16 IE1 1IE12 D 1D12
IK1 1IE1 22D 7 D 11
I 6
A DD 16
B EBEBE A 41 2
A 23 A24 C10 C18 C19 C28 C27
1
422
IE1 12 2
431
L P Y BRO Y±R
W± GLG
W± G B±W B±W
P±L
W
BRBR BR
B
BR
BR
Y
G± YBR(
*1)
BR BR
B
BB
B(
*1)
(
*1)
P±L
W P±L
W
(
*1)
(
*1)
(
*1)CAMS HAFT TIMING OIL
CONTROL VALVE C 2 VSV (
HC ADSORBER AND
CATALYST SYSTEM) V 3
HEATED OXYGEN SENSOR
(
BANK 1 SENSOR 1) H 3
HEATED OXYGEN SENSOR
(
BANK 1 SENSOR 2) H 9 BJUNCTION
CONNECTORB J22 A , J23
HT1B OX1 B E11 OX1A HT1A HCC E2SPHV
13HTE± HTE+ ETH+ ETH± OCV± OC V+ FAN
FROM FAN NO. 1 AND
FAN NO. 2 RE LAY
(
*1)
(
*1)(
*1)
(
*1) * 1 : SHIELDED
E10 , D C , E 9 AE 8, E 7 B
ENGINE CONTROL MODULE
I 6
(
*1)
BR D 5
V±W
SPD
TO COMBI NATION
METER
SPDO HTE± HTE+ ETH+ ETH1
D 6D29 D19 D28 D27
C 21
G
GO GO
B 10
C 16
R±Y
ESTP ESTP
D 8D 1 HYBRID VEHICLE CONTROL ECUD H12 , H14
B15A
STOP FROM POWER SOURCE SYSTEM (
SEE PAGE 50)
2K 9
1 2 DBEA
STOP LIGHT SW S 3JUNCTION
CONNECTORB J14 A , J15 G± W
G± W R± B
STPG±W
IA2 9
G
Page 70 of 1943
2001 PRIUS (EWD414U)
ENGINE CONTROL
2 1
2 1 I 7B 24 B16 A 10
EBA 21 A31
B A B A B AA A A A A AB 17
A AD 13 D 14 D 6 C 6C8 CE CE
CRANKSHAFT POSITION
SENSOR C 6 CAMSHAFT POSITION
SENSOR C 1
JUNCTION
CONNECTOR J16
GR GR±LG± R W± LP±B P±B
W±L R G GR
G G
BR
BR
BR (
*1)
(
*1)
BR
W± B
W± BBR BR
W±B
W±B G (
*1)(
*1)
(
*1)
(
*1) (
*1) (
*1)GR±LG± R W± LP±B
(
*1)
(
*1)
JUNCTION
CONNECTORB J 8 A , J 9
MPX2 MPX1 W SIL TC
E02 E01 E1 NE+ NE± G2ENGINE CONTROL MODULEB E 7 , E 8AE 9, C D, E10
A 28
EA1 1
1
B B KNOCK SENSOR K 1(
*1)
9A 3A
EA
W± B
W± BW±B
W±B
E03 ME01 FROM POWER SOURCE SYSTEM (
SEE PAGE 50)
15A
THRO
1A 8
A 6
+BM
GR GR
D 225
P±G
ACT NEO
LG
4
3D A/C AMPLIFIER A 8
KNK1
I 7I 7I 7
(
*1) (
*1) (
*1) NE ACT
Page 72 of 1943

2001 PRIUS (EWD414U)
ENGINE CONTROL
This system utilizes an engine control module and maintains overall control of the engine, transmission and so on. An outline
of the engine control is explained here.
1. INPUT SIGNALS
(1) Engine coolant temp. signal circuit
The engine coolant temp. sensor detects the engine coolant temp. and has a built±in thermistor with a resistance which
varies according to the engine coolant temp. thus the engine coolant temp. is input in the form of a control signal into
TERMINAL THW of the engine control module.
(2) Intake air temp. signal circuit
The intake air temp. sensor is installed in the mass air flow meter and detects the intake air temp., which is input as a
control signal into TERMINAL THA of the engine control module.
(3) Oxygen sensor signal circuit
The oxygen density in the exhaust gases is detected and input as a control signal into TERMINALS OX1A and OX1B of
the engine control module.
(4) RPM signal circuit
Camshaft position and crankshaft position are detected by the camshaft position sensor and crankshaft position sensor.
Camshaft position is input as a control signal to TERMINAL G2 of the engine control module, and engine RPM is input
into TERMINAL NE+.
(5) Throttle signal circuit
The throttle position sensor detects the throttle valve opening angle, which is input as a control signal into TERMINALS
VTA and VTA2 of the engine control module.
(6) Vehicle speed signal circuit
The vehicle speed signal from brake ECU, detects the vehicle speed and inputs a control signal into TERMINAL SPD of
the engine control module via the combination meter.
(7) Battery signal circuit
Voltage is constantly applied to TERMINAL BATT of the engine control module. When the ignition SW is turned on, the
voltage for engine control module start±up power supply is applied to TERMINAL +B of the engine control module via
EFI relay.
(8) Engine knock signal circuit
Engine knocking is detected by knock sensor and the signal is input into TERMINAL KNK1 of the engine control module
as a control signal.
2. CONTROL SYSTEM
*SFI system
The SFI system monitors the engine condition through the signals, which are input from each sensor to the engine
control module. The best fuel injection volume is decided based on this data and the program memorized by the engine
control module, and the control signal is output to TERMINALS #10, #20, #30 and #40 of the engine control module to
operate the injector. (Inject the fuel). The SFI system produces control of fuel injection operation by the engine control
module in response to the driving conditions.
*ESA system
The ESA system monitors the engine condition through the signals, which are input to the engine control module from
each sensor. The best ignition timing is detected according to this data and the memorized data in the engine control
module, and the control signal is output to TERMINALS IGT1, IGT2, IGT3 and IGT4. This signal controls the ignition coil
and igniter to provide the best ignition timing for the driving conditions.
*Fuel pump control system
The engine control module operation outputs to TERMINAL FC and controls the CIR OPN relay. Thus controls the fuel
pump drive speed in response to conditions.
3. DIAGNOSIS SYSTEM
With the diagnosis system, when there is a malfunctioning in the engine control module signal system, the malfunction
system is recorded in the memory. The malfunctioning system can then be found by reading the display (Code) of the
malfunction indicator lamp.
4. FAIL±SAFE SYSTEM
When a malfunction occurs in any system, if there is a possibility of engine trouble being caused by continued control based
on the signals from that system, the fail±safe system either controls the system by using data (Standard values) recorded in
the engine control module memory or else stops the engine.
SYSTEM OUTLINE
Page 73 of 1943

2001 PRIUS (EWD414U)
E7 (A), E8 (B), E9 (C), E10 (D) ENGINE CONTROL MODULE
BATT±E1 : Always approx. 9±14 volts
+B±E1 :9±14 volts with the ignition SW on and the engine stopping
VC±E2 :4.5±5.5 volts with the ignition SW on and the engine stopping
IGF±E1 : Pulse generation with the engine idling
THA±E2 :0.5±3.4 volts with the engine idling and the intake air temp. 20°C (68°F)
THW±E2 :0.2±1.0 volts with the engine idling and the engine coolant temp. 80°C (176°F)
W±E1 :9±14 volts with the engine idling
:0±3 volts with the ignition SW on and the engine coolant temp. sensor connector disconnects
ESTP±E1 :9±14 volts with the brake pedal depressed
FC±E01 :9±14 volts with the ignition SW on and the engine stopping
:0±3 volts with the engine idling
+BM±E1 : Always approx. 9±14 volts
MREL±E1 :9±14 volts with the ignition SW on and the engine stopping
EVP1±E1 :9±14 volts with the ignition SW on and the engine stopping
HT1A, HT1B :9±14 volts with the ignition SW on and the engine stopping
TC±E1 :9±14 volts with the ignition SW on and the engine stopping
KNK1±E2 : Pulse generation with the engine idling
NE+, G2±NE± : Pulse generation with the engine idling
OCV+ ±OCV± : Pulse generation with the ignition SW on and the engine stopping
IGT1, IGT2, IGT3, IGT4±E1 : Pulse generation with the engine idling
#10, #20, #30, #40±E01 : Pulse generation with the engine idling
E01, E02, E03, E1, E2, ME01±GROUND : Always continuity
E1 ENGINE COOLANT TEMP. SENSOR
2±1 : Approx. 14.96 kW (±20 °C, ±4 °F)
Approx. 2.44 kW (20 °C, 68 °F)
Approx. 0.31 kW (80 °C, 176 °F)
Approx. 0.14 kW (110 °C, 230 °F)
: PARTS LOCATION
CodeSee PageCodeSee PageCodeSee Page
A736H12B37J1737
A836H14D37J1837
B836I135J22A37
C134I235J23B37
C234I335J24A37
C634I435J25B37
C10A36I535J2637
C11B36I635K135
D236I735M135
E134I835N135
E7A36I1537O135
E8B36J137S337
E9C36J4A37T235
E10D36J5B37T335
F12C34J737V135
F13D34J8A37V235
F1638J9B37V335
F1838J1137V439
G137J14A37V539
H334J15B37V639
H937J1637
SERVICE HINTS
Page 116 of 1943
2001 PRIUS (EWD414U)
SEAT BELT WARNING
10A
GAUGE FROM POWER SOURCE SYSTEM (
SEE PAGE 50)
2A 5
A 22 B 3 B 2 B 5 A 16 A15
A 14 B 3
IJ1 9
1 3
IJ1 10
A AB A
ID 2D 8
2K 8IJ1 11
B D
A E
A A4
11 13
1 A
2 A 14
4 11
W±B W±B
W±B W±B
W± B
W± B W±BW±B P±L P±L
G±OG±O GR ±BGR
G±O
GR±B
GR
LGR ±B
L
L GR±L
GR±L
MPD1
MPX+ MPX2
PKBL MPX± MPX+ DBKL MPX1MPD2
MP2+
A/C AMPLIFIER A 7
GATEWAY ECU G 1 ENGINE CONTROL MODULE E10
BODY ECUB B 8 , B 9A
COMBINATION METERB C10 , C11A
JUNCTION CONNECTOR J29
15
A
JUNCTION CONNECTORB J2 4 A , J25
JUNCTION CONNECTORB J2 2 A , J23BUCKLE SW RH AND
SEAT BELT WARNING
OCCUPANT DETECTION SENSOR B21
IJ1 8
G±O JUNCTION
CONNECTOR J11
15A
DOME
1J 7
L±Y
2A 42G 2
A 21
L SEAT BELT
(
FRONT
PASSENGER' S SEAT) BUCKLE SW LH B20
SEAT BELT
(
DRIVER' S SEAT)IG
IH 2A 7
2B 6
BR
Page 117 of 1943

2001 PRIUS (EWD414U)
When the driver has not fastened the seat belt while the ignition SW is ON, the driver seat belt warning light blinks, and a
warning buzzer comes on.
Also, in the front passenger seat, a sensor recognizes a passenger, and when the passenger has not fastened the seat belt,
the front passenger seat belt warning light blinks.
B20 BUCKLE SW LH
1±2 : Closed with driver's seat belt in use
: PARTS LOCATION
CodeSee PageCodeSee PageCodeSee Page
A736C10A36J22A37
B8A36C11B36J23B37
B9B36E1036J24A37
B2038G137J25B37
B2138J1137J2937
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CodeSee PageJunction Block and Wire Harness (Connector Location)
1J27Engine Room Main Wire and Engine Room J/B (Engine Compartment Left)
2A
2B30Instrument Panel Wire and Instrument Panel J/B (Cowl Side Panel LH)
2D
()
2G31Engine Room Main Wire and Instrument Panel J/B (Cowl Side Panel LH)
2K31Cowl Wire and Instrument Panel J/B (Cowl Side Panel LH)
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CodeSee PageJoining Wire Harness and Wire Harness (Connector Location)
IJ144Floor No.3 Wire and Instrument Panel Wire (Under the Instrument Panel Center)
: GROUND POINTS
CodeSee PageGround Points Location
ID42Cowl Side Panel LH
IH42Right Kick Panel
SYSTEM OUTLINE
SERVICE HINTS
Page 124 of 1943
2001 PRIUS (EWD414U)
POWER WINDOW
15A
DOMEFROM POWER SOURCE SYSTEM (
SEE PAGE 50)
1J 720A
PWR1
2J 1110A
GAUGE
2K 1030A
POWER
23 15
2I 32K72K 1
B CBC
A AAA 2G 2
2D 4
IG1 1IC13IC18IC12
34
MIC1 7
11B F
A DAD 12 13 11 20 8 16
313
5 142
52 1
2
L±Y
W±R
R±L L±Y
R±L L±Y
W± R
R±L
B±L B±L
L±W GR
P±L
O
G
Y
R±Y R±Y
L±W
L±W
L±W
R±W
R±W R±W
POWER WINDOW MOTOR FRONT LH P10POWER WINDOW
MASTER SW P 9
DIODE
(
DOOR
COURTESY) D 4
DOOR
COURTESY SW
FRONT RH D 7
DOOR
COURTESY SW
FRONT LH D 6
JUNCTION
CONNECTORB J14 A , J15
JUNCTION
CONNECTORB J12 A , J13
CPUB
LMT SGND DDN DU DCTYDCTY
PLSBIGWLSW A B
B C
JUNCTION
CONNECTORB J24 A , J25L±Y
C
CJUNCTION
CONNECTOR J202 1
A 6
Y Y
18
MPX1RX
POWER
RELAY
IC1 19
W±B
E
IG A
JUNCTION
CONNECTOR J17
W±B
A
A
R±W R±W
JUNCTION
CONNECTOR J16
IB1 3
R±W R±W
7. 5A
ECU±B
2C 5B
9B
JUNCTION
CONNECTOR J27
R±G
R±GFF15BODY ECUB B 8 , B 9A
PULSE
SENSORLIMIT
SWIG1 5 IG
Page 163 of 1943
2001 PRIUS (EWD414U)
A 1A4A2A3 C 2
IO1 5
IGA AB ABAD 4D10 D 1D3D9 ID13
ID12
ID11
I 7B C E
2134
AA23 15WRL WRR TRQG TRQ2 TRQ1 TRQV PGND GR±G
P±B
WGR ±G
P±B
W
W± B
W±B W±BB G
R W
B
WGR±GP±B W±L W±B
EMPS ECUB E 3 , E 4AC, E 5 D, E 6
TS TC SIL
W±B
JUNCTION
CONNECTOR J17 STEERING SHAFT
TORQUE SENSOR S 1
BRAKE ECU B11
JUNCTION
CONNECTORB J18 , J19A VCC VT1 VT2 GND RRO RLO
(
SHIELDED)
(
SHIELDED)
JUNCTION
CONNE CTOR J16
(
SHIELDED)
EC B