2001 TOYOTA PRIUS horn

2001 PRIUS (EWD414U)
B HOW TO USE THIS MANUAL
The ground points circuit diagram shows the connections from all major parts to the respective ground points. When
troubleshooting a faulty ground point, checking the system circuits which use a common ground may help you identify
the problem ground quickly. The relationship between ground points (
EA, IB and IC shown below) can also be
checked this way.

I GROUND POINT
FAN MAIN RELAY
FAN MAIN RELAY
A/C FAN RELAY NO.2
A/C FAN RELAY NO.3
RADIATOR FAN MOTOR
RETRACT CONTROL
RELAY
RETRACT MOTOR RH
RETRACT MOTOR LH
FRONT TURN SIGNAL
LIGHT RH
PARKING LIGHT RH
FRONT TURN SIGNAL
LIGHT LH
PARKING LIGHT LH
DOOR LOCK CONTROL
SW RH
DOOR KEY LOCK
SW RH
DOOR LOCK MOTOR
RH
BLOWER RESISTOR
A/C AMPLIFIER
RADIO AND PLAYER
HEATER RELAY
AUTO ANTENNA
MOTOR
BLOWER SW
PARKING BRAKE SW
COMBINATION METER
HORN SW [COMB. SW]
TURN SIGNAL FLASHER
DOOR KEY LOCK SW LH
DOOR LOCK MOTOR LH
FUEL CONTROL SW
WOOFER AMPLIFIER
COMBINATION METER
COMBINATION METER
FUEL SENDER
CIGARETTE LIGHTER
O/D MAIN SW
CLOCK
5
5
5
5
4
4
4
4
4BA15
IB18
EA2 10
3E5
3E
6 3G
13 3F
3 3D
1 3B
7
ID115
IC33
IA12
E 3
A
A AW±B
W±BW±B W±B
W±B W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B W±BW±B W±B W±B W±B
W±B W±B
W±BW±B
W±B
W±B
W±B W±B
W±B
BR
W±B
BR BRW±BW±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B
W±B W±B
W±B
W±B
W±B
W±B
BR W±B
BR BR
BR W±B W±BW±B
W±BW±BBR W±B (4A±GZE)
W±B A A A
I 6
I 6
I 2
I 2
I 2
B 5I 5
I 5
I 5
B 5
B 5
B 5
I 5
I 5
I 3I 3
E 3
E 3
E 3
E 2
E 4
E 5
E 4
E 5
E 6E 4
E 4
B 4
EAI 4
B 4
B 4
I 4I 8
IBIC
3C7
4
JUNCTION
CONNECTOR J 1
4
DOOR LOCK CONTROL
RELAY
ELECTRICAL IDLE-UP
CUT RELAY (M/T)FRONT SIDE MARKER
LIGHT RH
FRONT SIDE MARKER
LIGHT LH
BRAKE FLUID LEVEL
WARNING SW
UNLOCK WARNING
SW WIPER AND WASHER
SW [COMB. SW] LIGHT CONTROL SW
[COMB. SW] HEATER CONTROL
ASSEMBLY
HEATER SERVO
MOTOR AMPLIFIER
DIMMER SW
[COMB. SW]
CRUISE CONTROL
MIRROR SW
REAR WINDOW
DEFOGGER SW
POWER WINDOW
MASTER SW
POWER WINDOW
CONTROL RELAY
DOOR LOCK CONTROL
SW
REMOTE CONTROL
MIRROR SW
*The system shown here is an EXAMPLE ONLY. It is different to the actual circuit shown in the SYSTEM CIRCUITS SECTION.

2001 PRIUS (EWD414U)
B
The ºCurrent Flow Chartº section, describes which parts each power source (fuses, fusible links, and circuit breakers)
transmits current to. In the Power Source circuit diagram, the conditions when battery power is supplied to each system
are explained. Since all System Circuit diagrams start from the power source, the power source system must be fully
understood.
Theft Deterrent and Door Lock Control
J POWER SOURCE (Current Flow Chart)
11
1
EA1 1EA2 3
7
EB16
E 6
E 7I 2I 2
I 2
E 7
E 7
E 7
2
1
1
2
2
2
2
2
B
B
W W
B B B B BW±B
B
B
B B±O
B±W
W±B
B±W STARTER RELAY INJECTION RELAY15A HAZ±RADIO7.5A AM250A MAIN 1.25B FL MAIN
BATTERY
WWW
W W W
R W±L
W
W
G±W
G
15A TAIL
20A DEFOG
15A RAD CIGTA I L
RELAY 7.5A DOME 40A DOOR LOCK CB
2 1
1 2
4 8
2 3
3 4
G
W±R
P±L B±Y
B±Y
W±R
AM2 IG2
ACC
IG1AM1W W
W±R
W W
W±B
21
1
1
1
1
2
2
2
2
3
4
3
4 1
2
1
22
1
11
1
IGNITION SW I 8
Battery
30A AM2
2
Starter S 220A RADIO NO.1
10A HORN
15A EFI
7.5A DOMEShort Pin
10A HAZARD
The chart below shows the route by which current flows from the battery to each electrical source
(Fusible Link, Circuit Breaker, Fuse, etc.) and other parts.
Engine Room R/B (See Page 20)
ABS
ABS and Traction Control
Cruise Control
Electronically Controlled Transmission and A/T Indicator
Multiplex Communication System
Cigarette Lighter and Clock
Key Reminder and Seat Belt Warning STOP
Fuse Page
194
214
11 2
System
DOME 20A
10ACombination Meter
Headlight
Interior Light
2
2
6 100A ALT
EB1
POWER SOURCE
Light Auto Turn Off187
180
166
210
230
122
10A ECU±B
5 60A ABS
2
6 Fusible Link Block2
*The system shown here is an EXAMPLE ONLY. It is different to the actual circuit shown in the SYSTEM CIRCUITS SECTION.

2001 PRIUS (EWD414U)
E GLOSSARY OF TERMS AND SYMBOLS
BATTERY
Stores chemical energy and
converts it into electrical energy.
Provides DC current for the auto's
various electrical circuits.GROUND
The point at which wiring attaches to
the Body, thereby providing a return
path for an electrical circuit; without a
ground, current cannot flow.
CAPACITOR (Condenser)
A small holding unit for temporary
storage of electrical voltage.HEADLIGHTS
Current flow causes a headlight
filament to heat up and emit light. A
headlight may have either a single
(1) filament or a double (2) filament
1. SINGLE
FILAMENT
CIGARETTE LIGHTER
An electric resistance heating
element.2. DOUBLE
FILAMENT
CIRCUIT BREAKER
Basically a reusable fuse, a circuit
breaker will heat and open if too
much current flows through it.
Some units automatically reset when
cool, others must be manually reset.HORN
An electric device which sounds a
loud audible signal.
DIODE
A semiconductor which allows
current flow in only one direction.IGNITION COIL
Converts low±voltage DC current
into high±voltage ignition current for
firing the spark plugs.
DIODE, ZENERA diode which allows current flow in one
direction but blocks reverse flow only up
to a specific voltage. Above that potential,
it passes the excess voltage. This acts as
a simple voltage regulator.LIGHT
Current flow through a filament
causes the filament to heat up and
emit light.
PHOTODIODE
The photodiode is a semiconductor
which controls the current flow
according to the amount of light.LED (LIGHT EMITTING DIODE)
Upon current flow, these diodes emit
light without producing the heat of a
comparable light.
DISTRIBUTOR, IIA
Channels high±voltage current from
the ignition coil to the individual
spark plugs.METER, ANALOG
Current flow activates a magnetic
coil which causes a needle to move,
thereby providing a relative display
against a background calibration.
FUSEA thin metal strip which burns through
when too much current flows through it,
thereby stopping current flow and
protecting a circuit from damage.
FUSIBLE LINK
METER, DIGITAL
Current flow activates one or many
LED's, LCD's, or fluorescent
displays, which provide a relative or
digital display.
FUEL
FUSIBLE LINK
A heavy±gauge wire placed in high
amperage circuits which burns through on
overloads, thereby protecting the circuit.
The numbers indicate the crosssection
surface area of the wires.(for Medium Current Fuse)
(for High Current Fuse or
Fusible Link)MOTOR
A power unit which converts
electrical energy into mechanical
energy, especially rotary motion.
M

2001 PRIUS (EWD414U)
G ELECTRICAL WIRING ROUTING
Position of Parts in Engine Compartment
A 1 A/C Condenser Fan Motor
A 2 A/C Magnetic Clutch and Lock Sensor
A 3 A/C Triple Pressure SW
(A/C Dual and Single Pressure SW)
A 4 ABS Speed Sensor Front LH
A 5 ABS Speed Sensor Front RH
A 6 Ambient Temp. Sensor
B 1 Brake Actuator
B 2 Brake Actuator
B 3 Brake Actuator
B 4 Brake Fluid Level Warning SW
C 1 Camshaft Position Sensor
C 2 Camshaft Timing Oil Control Valve
C 3 Circuit Breaker Sensor
C 4 Converter
C 5 Converter
C 6 Crankshaft Position Sensor
D 1 DC Motor
E 1 Engine Coolant Temp. Sensor
E 2 Engine Hood Courtesy SWF 1 Front Airbag Sensor LH
F 2 Front Airbag Sensor RH
F 3 Front Parking Light LH
F 4 Front Parking Light RH
F 5 Front Side Marker Light LH
F 6 Front Side Marker Light RH
F 7 Front Turn Signal Light LH
F 8 Front Turn Signal Light RH
F 9 Front Wiper Motor
F 10 Fusible Link Block No.1
F 11 Fusible Link Block No.1
F 12 Fusible Link Block No.1
F 13 Fusible Link Block No.1
H 1 Headlight LH
H 2 Headlight RH
H 3 Heated Oxygen Sensor (Bank 1 Sensor1)
H 4 Horn
H 5 Hydraulic Booster
H 6 Hydraulic Booster

2001 PRIUS (EWD414U)
G
Position of Parts in Engine Compartment
I 1 Ignition Coil and Igniter No.1
I 2 Ignition Coil and Igniter No.2
I 3 Ignition Coil and Igniter No.3
I 4 Ignition Coil and Igniter No.4
I 5 Injector No.1
I 6 Injector No.2
I 7 Injector No.3
I 8 Injector No.4
I 9 Inverter
I 10 Inverter
I 11 Inverter
I 12 Inverter
I 13 Inverter
I 14 Inverter
K 1 Knock Sensor
M 1 Mass Air Flow Meter
M 2 Motor Generator No.1
M 3 Motor Generator No.2
M 4 Motor Generator No.2N 1 Noise Filter (Ignition)
O 1 Oil Pressure SW
R 1 Radiator Fan Motor
S 1 Steering Shaft Torque Sensor
T 1 Theft Deterrent Horn
T 2 Throttle Control Motor
T 3 Throttle Position Sensor
V 1 Vacuum Sensor (HC Adsorber and Catalyst System)
V 2 VSV (EVAP)
V 3 VSV (HC Adsorber and Catalyst System)
W 1 Washer Motor
W 2 Water Pump Motor (A/C)
W 3 Water Pump Motor (Inverter)
W 4 Water Temp. SW

2001 PRIUS (EWD414U)
POWER SOURCE
B 1B 1A1
D 1C131240A ABS NO. 1
1250A EMPS
1250A HTR3
12
123
3
3
3
3
1
3 1B3
1B1
21
1
42
341
42
3 1 1B2
1J9 W
W
W
W
W
FUSIBLE
LINK BLOCK NO. 1D F12 C , F1 3B F10 A , F1 1
30A CDS FAN
15A THRO15A EFI
10A HORN
10A TURN±HAZ
15A DOME
10A BATT FAN15A AM2
20A ABS NO. 3 20A HV
10A HEAD LO (
RH)
10A HEAD LO (
LH)
10A HEAD HI (
LH)
10A HEAD HI (
RH) SHORT PIN SHORT PIN
HEAD RELAY
BATTERY5A DC/DC±S
B±G
B
B
B
W± RW
30A HTR2
30A HTR1
10A ABS NO. 4 100A
DC/DC
120A
MAIN30A HEAD (
*1)
(
*2)
DIM RELAYW±R 12 12
30A RDI 50A HTR
2W±R
B±R
G
G±W
B±R
L2C2
2G1
1230A ABS NO. 2
3127. 5A DRL
3R±L 12(
*1)
(
*2)
1J 11
R
TO CONVERTER
A2
B±R
TO CONVERTER
FUSIBLE LINK
BLOCK NO. 2B F17 , F18A
1 5SHORT PIN
(
*2)

2001 PRIUS (EWD414U)
HORN
10A
HORN FROM POWER SOURCE SYSTEM (
SEE PAGE 50)
23 15
1J 21F9
1
IA2 8
D D
6HORN
RELAY
B±R
B±W B±R B±R
HORN SW
[COMB. SW] C14 JUNCTION
CONNECTOR J20HORN H 4

2001 PRIUS (EWD414U)
HORN RELAY
5±3 : Closed with the horn SW on
: PARTS LOCATION
CodeSee PageCodeSee PageCodeSee Page
C1436H434J2037
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CodeSee PageJunction Block and Wire Harness (Connector Location)
1F27Engine Room Main Wire and Engine Room J/B (Engine Compartment Left)1J27Engine Room Main Wire and Engine Room J/B (Engine Compartment Left)
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CodeSee PageJoining Wire Harness and Wire Harness (Connector Location)
IA242Engine Room Main Wire and Cowl Wire (Cowl Side Panel LH)
SERVICE HINTS