2001 TOYOTA PRIUS service

NOTICE
When handling supplemental restraint system components (removal,
installation or inspection, etc.), always follow the direction given in the repair
manuals listed above to prevent accidents and supplemental restraint
system malfunction.
CAUTION
When repairing the hybrid vehicle (HV), always follow the direction given in
the repair manual listed above to prevent electrical shock, leakage or
explosion.
2001 PRIUS (EWD414U)
FOREWORD
This wiring diagram manual has been prepared to provide
information on the electrical system of the 2001 PRIUS.
Applicable models: NHW11 Series
For service specifications and repair procedures of the above
models other than those listed in this manual, refer to the
following manuals;
Manual Name
Pub. No.

2001 PRIUS Repair Manual
Volume 1
Volume 2

2001 PRUIS New Car Features
RM778U1
RM778U2
NCF182U
All information in this manual is based on the latest product
information at the time of publication. However, specifications
and procedures are subject to change without notice.

2001 PRIUS (EWD414U)
A INTRODUCTION
This manual consists of the following 13 sections:
No.
SectionDescription
A
INDEXIndex of the contents of this manual.
A
INTRODUCTIONBrief explanation of each section.
BHOW TO USE THIS
MANUALInstructions on how to use this manual.
CTROUBLE±
SHOOTINGDescribes the basic inspection procedures for electrical circuits.
DABBREVIATIONSDefines the abbreviations used in this manual.
E
GLOSSARY OF
TERMS AND
SYMBOLS
Defines the symbols and functions of major parts.
FRELAY LOCATIONSShows position of the Electronic Control Unit, Relays, Relay Block, etc.
This section is closely related to the system circuit.
GELECTRICAL
WIRING ROUTINGDescribes position of Parts Connectors, Splice points, Ground points, etc.
This section is closely related to the system circuit.
INDEXIndex of the system circuits.
H
SYSTEM CIRCUITS
Electrical circuits of each system are shown from the power supply through ground
points. Wiring connections and their positions are shown and classified by code
according to the connection method. (Refer to the section, ºHow to use this manualº).
The ºSystem Outlineº and ºService Hintsº useful for troubleshooting are also contained
in this section.
IGROUND POINTShows ground positions of all parts described in this manual.
JPOWER SOURCE
(Current Flow Chart)Describes power distribution from the power supply to various electrical loads.
KCONNECTOR LISTDescribes the form of the connectors for the parts appeared in this book.
This section is closely related to the system circuit.
LPART NUMBER OF
CONNECTORSIndicates the part number of the connectors used in this manual.
M
OVERALL
ELECTRICAL
WIRING DIAGRAM
Provides circuit diagrams showing the circuit connections.

[O]
[P]
[Q]
[R]
[S]
[T]
[U]
[V]
2001 PRIUS (EWD414U)
B HOW TO USE THIS MANUAL
Current is applied at all times through the STOP fuse to TERMINAL 2 of the stop light SW.
When the ignition SW is turned on, current flows from the GAUGE fuse to TERMINAL 8 of the light failure sensor, and also flows
through the rear lights warning light to TERMINAL 4 of the light failure sensor.
STOP LIGHT DISCONNECTION WARNING
When the ignition SW is turned on and the brake pedal is pressed (Stop light SW on), if the stop light circuit is open, the current
flowing from TERMINAL 7 of the light failure sensor to TERMINALS 1, 2 changes, so the light failure sensor detects the
disconnection and the warning circuit of the light failure sensor is activated.
As a result, the current flows from TERMINAL 4 of the light failure sensor to TERMINAL 11 to GROUND and turns the rear lights
warning light on. By pressing the brake pedal, the current flowing to TERMINAL 8 of the light failure sensor keeps the warning
circuit on and holds the warning light on until the ignition SW is turned off.
S6 STOP LIGHT SW
2±1 : Closed with the brake pedal depressed
L4 LIGHT FAILURE SENSOR
1, 2, 7±GROUND : Approx. 12 volts with the stop light SW on
4, 8±GROUND : Approx. 12 volts with the ignition SW at ON position
11±GROUND : Always continuity
: PARTS LOCATION
CodeSee PageCodeSee PageCodeSee Page
C734L436R737
H1736R637S635
: RELAY BLOCKS
CodeSee PageRelay Blocks (Relay Block Location)
118R/B No.1 (Instrument Panel Left)

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ÀÀÀ ÀÀÀ ÀÀÀ
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CodeSee PageJunction Block and Wire Harness (Connector Location)
IB20Instrument Panel Wire and Instrument Panel J/B (Lower Finish Panel)
3C22Instrument Panel Wire and J/B No.3 (Instrument Panel Left Side)
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CodeSee PageJoining Wire Harness and Wire Harness (Connector Location)
IE142Floor Wire and Instrument Panel Wire (Left Kick Panel)
BV150Luggage Room Wire and Floor Wire (Luggage Compartment Left)
: GROUND POINTS
CodeSee PageGround Points Location
BL50Under the Left Quarter Pillar
BO50Back Panel Center
: SPLICE POINTS
CodeSee PageWire Harness with Splice PointsCodeSee PageWire Harness with Splice Points
I544Cowl WireB1850Luggage Room Wire
SYSTEM OUTLINE
SERVICE HINTS

2001 PRIUS (EWD414U)
POWER SOURCE
HEAD RELAY
2±1 : Closed with the light control SW at HEAD position or the dimmer SW at FLASH position
Closed with the engine running and the parking brake pedal released (Parking brake SW off) [w/ Daytime running light]
TAIL RELAY
5±3 : Closed with the light control SW at TAIL or HEAD position
I15 IGNITION SW
2±3 : Closed with the ignition key at ACC or ON position
2±4 : Closed with the ignition key at ON or ST position
7±6 : Closed with the ignition key at ON or ST position
7±8 : Closed with the ignition key at ST position
: PARTS LOCATION
CodeSee PageCodeSee PageCodeSee Page
F10A34F13D34I1537
F11B34F17A38
F12C34F18B38
: RELAY BLOCKS
CodeSee PageRelay Blocks (Relay Block Location)
324Engine Room R/B No.3 (Engine Compartment Right)
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CodeSee PageJunction Block and Wire Harness (Connector Location)
1B27Engine Room Main Wire and Engine Room J/B (Engine Compartment Left)1J27Engine Room Main Wire and Engine Room J/B (Engine Compartment Left)
2B
2C30Instrument 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)2H31Engine Room Main Wire and Instrument Panel J/B (Cowl Side Panel LH)
SERVICE HINTS

2001 PRIUS (EWD414U)
TOYOTA HYBRID SYSTEM
HYBRID VEHICLE CONTROL ECUA H10 , H11
CB, H12
E , H13
D , H14
W± BW± B HTB± BTH+
18 D
G
14
HVO+ HVO±22
R
D 17BTH±
30 D
V
16
HVI± HTB+
20 D
LG
24
HVI+ B 14 B15
1
2
G±R
G±R BR±B CIRCUIT BREAKER SENSOR C 3
AS1G AS1
BRAKE ECU B1 1
GR± B
V± Y
GR
O
LG±B
L±O
LG
P
Y± B
L±W
L
LG±R
Y
P±L
G
L±R
G± W
R
W
L±B
14 2 15 3 16 4 17 5 18 6 7 20 8 21 9 22 10 23 11 24HYBRID VEHICLE BATTERY
BUSBER MODULED 10TC
D 21SIL
D 9WF SE
ID1 2ID11 ID1 10CE
E
13 15C
E
P
P±B P±BY Y
P±B P
P±B
W± L W±L
EJUNCTION
CONNECTOR J1 6
TC WF SEE 10HAI
Y±R
E 9HAO
Y±R12
OP28
OP3JUNCTION
CONNECTOR J26 W±GW±G
W
1234
L
L
B
B
W
W
5
W
7
SIL
O(
*2) O(
*2)
A 1B 1
SERVICE PLUG
O
(
*2)O
(
*2)
HYBRID VEHICLE BATTERY
BUSBER MODULESENSOR
O O
(
*2)
(
*2)
HYBRID VEHICLE
BATTERYB H16 , H17A
BATTERY ECUB B17 , B18A
W
DATA LINK
CONNECTOR 3 D 2

2001 PRIUS (EWD414U)
6. MANUAL CANCEL CONTROL
When each of the following signals is input during driving with cruise control, the cruise control is released with turning the
cruise control requirement to 0. (The memorized speed is maintained when following signals except the signal, main switch
OFF is input.)
*Stop light switch ON (Pressing the brake pedal)
*Control switch's cancel switch ON
*Main switch OFF
7. AUTO CANCEL FUNCTION
A) The memorized speed is erased and the control is canceled if the following conditions occur. The power indicator blinks
at that time until the main switch is turned ON. The speed control is unavailable unless the main switch is turned ON
again.
*When the stop light switch breaks or short±circuits.
*When sudden change of the running speed signal occur.
B) The memorized speed is erased and the control is canceled if the following conditions occur.
*When the malfunction of the stop light switch input circuit occurs.
*When the running speed becomes slower than 40km/h.
*When the running speed becomes slower than the speed that 16 km/h subtracted from the memorized speed.
8. REGENERATIVE SYSTEM OPERATION
This system operates the motor as a generator to change the kinetic energy of the vehicle into the electricity when accel
pedal release or foot braking controls the vehicle, and store the electricity in the battery.
C14 CRUISE CONTROL SW [COMB. SW]
5±4 : Approx. 1540 W with CANCEL SW on
Approx. 240 W with RES/ACC SW on
Approx. 630 W with SET/COAST SW on
: PARTS LOCATION
CodeSee PageCodeSee PageCodeSee Page
A736H10C37J18A37
A1336H11A37J19B37
A1836H12B37J2137
B836H13E37J22A37
B1136H14D37J23B37
B1538H16A38J24A37
B1638H17B38J25B37
B17A38I9D35J2637
B18B38I10C35J27A37
B1938I11A35J28B37
C334I12B35J3238
C4A34I13E35A38
C5B34I14F35J33B38
C10A36I1537M2A35
C11B36I1738M3B35
C1436J137M4C35
D236J2A37P137
E9C36J3B37S337
E10D36J737S8A39
F1034J8A37S9B39
F12C34J9B37S10C39
F13D34J1137S11D39
F1738J1637S12E39
F1838J1737T437
G137J1837W335
SERVICE HINTS

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

2001 PRIUS (EWD414U)
T4 TRANSPONDER KEY COMPUTER
1±GROUND : Always approx. 12 volts
12±GROUND : Always continuity
U1 UNLOCK WARNING SW
1±2 : Closed with the ignition key in cylinder
: PARTS LOCATION
CodeSee PageCodeSee PageCodeSee Page
C736I1537J25B37
D236J1037J27A37
D638J1137J28B37
F12C34J12A37R3B37
F13D34J13B37R4C37
F1838J2037T437
H1437J24A37U137
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CodeSee PageJunction Block and Wire Harness (Connector Location)
1B27Engine Room Main Wire and Engine Room J/B (Engine Compartment Left)1J27Engine Room Main Wire and Engine Room J/B (Engine Compartment Left)
2C30Instrument Panel Wire and Instrument Panel J/B (Cowl Side Panel LH)2D30Instrument Panel Wire and Instrument Panel J/B (Cowl Side Panel LH)
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)
IB142Floor Wire and Cowl Wire (Cowl Side Panel LH)
ID142Instrument Panel Wire and Cowl Wire (Left Kick Panel)ID242Instrument Panel Wire and Cowl Wire (Left Kick Panel)
: GROUND POINTS
CodeSee PageGround Points Location
ID42Cowl Side Panel LH
IF42Left Kick Panel
SERVICE HINTS