Toyota COROLLA2004 Quick start guide

2003
All rights reserved. This book may not be
reproduced or copied, in whole or in part, without
the written permission of Toyota Motor
Corporation.
2004 COROLLA (EWD533U) 1
2004 COROLLA
ELECTRICAL WIRING DIAGRAM
Section Code Page
INTRODUCTION A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
HOW TO USE THIS MANUAL B. . . . . . . . . . . . . . . . . . 3
TROUBLESHOOTING C. . . . . . . . . . . . . . . . . . . . . . . . . 12
ABBREVIATIONS D. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
GLOSSARY OF TERMS AND SYMBOLS E. . . . . . . . 18
RELAY LOCATIONS F. . . . . . . . . . . . . . . . . . . . . . . . . . . 20
ELECTRICAL WIRING ROUTING G. . . . . . . . . . . . . . . 32
SYSTEM CIRCUITS H. . . . . . . . . . . . . . . . . . . . . . . . . . . 47
GROUND POINT I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
POWER SOURCE (Current Flow Chart) J. . . . . . . . . 198
CONNECTOR LIST K. . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
PART NUMBER OF CONNECTORS L. . . . . . . . . . . . . 210
OVERALL ELECTRICAL WIRING DIAGRAM M. . . . . 214

2004 COROLLA (EWD533U)
2
A INTRODUCTION
This manual consists of the following 13 sections:
No. Section Description
A
INDEX Index of the contents of this manual.
AINTRODUCTION Brief explanation of each section.
BHOW TO USE THIS
MANUAL Instructions on how to use this manual.
CTROUBLE–
SHOOTING Describes the basic inspection procedures for electrical circuits.
D ABBREVIATIONS Defines the abbreviations used in this manual.
EGLOSSARY OF
TERMS AND
SYMBOLS Defines the symbols and functions of major parts.
FRELAY LOCATIONS Shows position of the Electronic Control Unit, Relays, Relay Block, etc.
This section is closely related to the system circuit.
GELECTRICAL
WIRING ROUTING Describes position of Parts Connectors, Splice points, Ground points, etc. This section is closely related to the system circuit.
INDEX Index of the system circuits.
HSYSTEM 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, ”How to use this manual”).
The ”System Outline” and ”Service Hints” useful for troubleshooting are also contained
in this section.
IGROUND POINT Shows 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 LIST Describes the form of the connectors for the parts appeared in this book.
This section is closely related to the system circuit.
LPART NUMBER OF
CONNECTORS Indicates the part number of the connectors used in this manual.
MOVERALL
ELECTRICAL
WIRING DIAGRAM Provides circuit diagrams showing the circuit connections.

2004 COROLLA (EWD533U) 3
HOW TO USE THIS MANUAL B
This manual provides information on the electrical circuits installed on vehicles by
dividing them into a circuit for each system.
The actual wiring of each system circuit is shown from the point where the power
source is received from the battery as far as each ground point. (All circuit
diagrams are shown with the switches in the OFF position.)
When troubleshooting any problem, first understand the operation of the circuit
where the problem was detected (see System Circuit section), the power source
supplyingpower to that circuit (see Power Source section), and the ground points
(see Ground Point section). See the System Outline to understand the circuit
operation.
When the circuit operation is understood, begin troubleshooting of the problem
circuit to isolate the cause. Use Relay Location and Electrical Wiring Routing
sections to find each part, junction block and wiring harness connectors, wiring
harness and wiring harness connectors, splice points, and ground points of each
system circuit. Internal wiring for each junction block is also provided for better
understandingof connection within a junction block.
Wiring related to each system is indicated in each system circuit by arrows
(from__, to__). When overall connections are required, see the Overall Electrical
Wiring Diagram at the end of this manual.

[A]
[B]
[H]
[D]
[F]
[E]
[ I ]
[L]
[M]
[J]
[K]
[G]
[C]
1
2
IB
IB
3
4
47
2111
13
4
1
2
6
3
1
2
B18
BL
RL
GR
B18
GR
3
4
Rear Combination Light RH R 7 Rear Combination Light LH R 6
High Mounted
Stop Light
H17
Light Failure Sensor
Stop Light SW
ABS ECU
S 6
Combination
Meter
C 7
BV1
1WB
(Shielded)
BV1
1
I 5
GW
IB2
IB1
IE114
BO
50
8L 4
15A
STOP 7.5A GAUGE
From Power Source System (See Page 66)
Stop Light
GRWBWB
WB
WB
GB
YG RL
R
GR
WRGW
WB
GW
W/G)
(S/D)LL
(
(S/D)
Stop Stop
Rear Lights
2004 COROLLA (EWD533U)
4
B HOW TO USE THIS MANUAL
∗The system shown here is an EXAMPLE ONLY. It is different to the actual
circuit shown in the SYSTEM CIRCUITS SECTION.

2004 COROLLA (EWD533U) 5
B
[A] : System Title
[B] : Indicates a Relay Block. No shading is used and
only the Relay Block No. is shown to distinguish it
from the J/B
Example: Indicates Relay Block No.1
[C] : ( ) is used to indicate different wiring and
connector, etc. when the vehicle model, engine
type, or specification is different.
[D] : Indicates related system.
[E] : Indicates the wiring harness and wiring harness
connector. The wiring harness with male terminal is
shown with arrows ( ).
Outside numerals are pin numbers.
Female Male ( )
The first letter of the code for each wiring harness
and wiring harness connector(s) indicates the
component’s location, e.g, ”E” for the Engine
Compartment, ”I” for the Instrument Panel and
Surrounding area, and ”B” for the Body and
Surrounding area.
When more than one code has the first and second
letters in common, followed by numbers (e.g, IH1,
IH2), this indicates the same type of wiring harness
and wiring harness connector.
[F] : Represents a part (all parts are shown in sky blue).
The code is the same as the code used in parts
position.
[G] : Junction Block (The number in the circle is the J/B
No. and the connector code is shown beside it).
Junction Blocks are shaded to clearly separate
them from other parts.
3C indicates that
it is inside
Junction Block
No.3
Example:
[H] : Indicates the wiring color.
Wire colors are indicated by an alphabetical code.
B = Black W = White BR = Brown
L = Blue V = Violet SB = Sky Blue
R = Red G = Green LG = Light Green
P = Pink Y = Yellow GR= Gray
O = Orange
The first letter indicates the basic wire color and the
second letter indicates the color of the stripe.
Example: L – Y
L
(Blue) Y (Yellow)
[I] : Indicates a wiring Splice Point (Codes are ”E” for the
Engine Room, ”I” for the Instrument Panel, and ”B”
for the Body).
The Location of splice Point I 5 is indicated by the
shaded section.
[J] : Indicates a shielded cable.
[K] : Indicates the pin number of the connector.
The numbering system is different for female and
male connectors.
Example: Numbered in order
from upper left to
lower right
Numbered in order
from upper right to
lower left
Female Male
[L] : Indicates a ground point.
The first letter of the code for each ground point(s)
indicates the component’s location, e.g, ”E” for the
Engine Compartment, ”I” for the Instrument Panel
and Surrounding area, and ”B” for the Body and
Surrounding area.
[M] : Page No.

[N]
[O]
[P]
[Q]
[R]
[S]
[T]
[U]
2004 COROLLA (EWD533U)
6
B HOW TO USE THIS MANUAL
Currentis 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
disconnectionand 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
warninglight 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
Code See Page Code See Page Code See Page
C7 34 L4 36 R7 37
H17 36 R6 37 S6 35
: Relay Blocks
Code See Page Relay Blocks (Relay Block Location)
118 R/B No.1 (Instrument Panel Brace LH)
: Junction Block and Wire Harness Connector
Code See Page Junction Block and Wire Harness (Connector Location)
IB 20 Instrument Panel Wire and Instrument Panel J/B (Lower Finish Panel)
3C 22 Instrument Panel Wire and J/B No.3 (Instrument Panel Brace LH)
: Connector Joining Wire Harness and Wire Harness
Code See Page Joining Wire Harness and Wire Harness (Connector Location)
IE1 42 Floor Wire and Instrument Panel Wire (Left Kick Panel)
BV1 50 Luggage Room Wire and Floor Wire (Luggage Room Left)
: Ground Points
Code See Page Ground Points Location
BL 50 Under the Left Center Pillar
BO 50 Back Panel Center
: Splice Points
Code See Page Wire Harness with Splice Points Code See Page Wire Harness with Splice Points
I5 44 Cowl Wire B18 50 Luggage Room Wire
System Outline
Service Hints

2004 COROLLA (EWD533U) 7
B
[N] : Explains the system outline.
[O] : Indicates values or explains the function for reference during troubleshooting.
[P] : Indicates the reference page showing the position on the vehicle of the parts in the system circuit.
Example : Part ”L4” (Light Failure Sensor) is on page 36 of the manual.
∗The letter in the code is from the first letter of the part, and the number indicates its order in parts
starting with that letter. Example : L 4
Á
Á
Parts is 4th in order
Light Failure Sensor
[Q] : Indicates the reference page showing the position on the vehicle of Relay Block Connectors in the system circuit.
Example : Connector ”1” is described on page 18 of this manual and is installed on the left side of the instrument
panel.
[R] : Indicates the reference page showing the position on the vehicle of J/B and Wire Harness in the system circuit.
Example : Connector ”3C” connects the Instrument Panel Wire and J/B No.3. It is described on page 22 of this
manual, and is installed on the instrument panel left side.
[S] : Indicates the reference page describing the wiring harness and wiring harness connector (the female wiring
harness is shown first, followed by the male wiring harness).
Example : Connector ”IE1” connects the floor wire (female) and Instrument panel wire (male). It is described on
page 42 of this manual, and is installed on the left side kick panel.
[T] : Indicates the reference page showing the position of the ground points on the vehicle.
Example : Ground point ”BO” is described on page 50 of this manual and is installed on the back panel center.
[U] : Indicates the reference page showing the position of the splice points on the vehicle.
Example : Splice point ”I5” is on the Cowl Wire Harness and is described on page 44 of this manual.

2004 COROLLA (EWD533U)
8
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.
5
5
5
5
4
4
4
4
4BA1
5
IB1
8
EA2
ID1
15
IC3
3
IA1
2
E 3
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
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
W–B
W–BW–B
W–B
W–B
W–B
W–BW–B W–B
W–B
W–B
W–B
W–B
W–B
BR
W–B
BRBR
BR
W–B(4A–GZE)
W–BW–B
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
EA
I 4
B 4
B 4
I 4 I 8
IB IC
4
4
3E
5
3E
6
3G
13
3F
3
3D
1
3B
7
W–B
W–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
I 6
I 6
I 2
3C
7
10
A
A
A
A
A
A
Junction
Connector
J 1
W–B
W–B
W–B W–B
BR
W–B
W–B
W–B
W–B
W–B W–B
I GROUND POINT
FAN MAIN Relay
FAN MAIN Relay
A/C Relay No.2
A/C Relay No.3
Radiator Fan Motor
Headlight Cleaner Relay
Headlight LH
Headlight RH
Front Fog Light LH
Brake Fluid Level SW
Front Fog Light RH
Front Turn Signal Light RH
Front Clearance Light RH
Front Turn Signal Light LH
Front Clearance Light LH
Door Lock Control SW
Door Courtesy SW RH
Door Lock Motor RH
Door Lock Control Relay
Blower Resistor
Idle–Up SW
A/C Amplifier
Radio and Player
HEATER Relay
Auto Antenna Motor
A/C Control Assembly
Blower Motor
Blower SW
Parking Brake SW
Combination Meter
Combination SW
Cruise Control ECU
Remote Control Mirror SW
Turn Signal Flasher
Defogger SW
Unlock Warning SW
Power Window Master SW
Power Window Control
Relay
Door Courtesy SW LH
Door Lock Control SW
Door Lock Motor LH
Fuel Control SW
Woofer Speaker Amplifier
Combination Meter
Combination Meter
Fuel Sender
Cigarette Lighter
O/D Main SW
Clock
Combination SW
∗The system shown here is an EXAMPLE ONLY. It is different to the actual circuit shown in the SYSTEM CIRCUITS SECTION.

2004 COROLLA (EWD533U) 9
B
The ”Current Flow Chart” 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.
ACC
S 2
6
65
2
2
2
Battery 30A AM2
Starter
Short Pin
100A ALT
Fusible Link Block
60A ABS
10A ECU–B
7.5A DOME
15A EFI
10A HAZARD
20A RADIO NO.1
10A HORN
20A
10A
Fuse Page
214
230
112
122
194
187
180
166
210
ABS
Cigarette Lighter
Combination Meter
Key Reminder and Seat Belt Warning
Light Auto Turn Off
Theft Deterrent and Door Lock Control
ABS and Traction Control
Cruise Control
Electronically Controlled Transmission
Multiplex Communication System
STOP
System
DOME Headlight Interior Light
3 EA2 1 EA1
E 6
E 7
E 7
2
2
2
2
2
2
2
2
INJECTION Relay
STARTER Relay
B
B
B
B–O 1
1
2
2
3
4
3
4
W–B
W–B
B–W
B–W
E 7
E 7
B
B
W1.25B FL MAIN
50A MAIN
7.5A AM2
15A HAZ–RADIO
2
2
2
2
2
W
W
EB1
EB1
7
6
W–R
I 2 I 2
I 2
WW
W
W
W
1
1
1
1
40A DOOR LOCK CB
7.5A DOME
1W–L
R
1
1
2
43
1
11
1
11
1
G
G
W–R
15A TAIL
20A DEFOG
B–Y
84
32
Ignition SW
I 8
B–Y 11 P–L
Battery
15A RAD CIG
2
TAIL
Relay
Power Source
J POWER SOURCE (Current Flow Chart)
Engine Room R/B (See Page 20)
2
W W
BBBBB
W–R
WWW
G–W
AM2
AM1
IG2 IG1
W
W
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.
∗The system shown here is an EXAMPLE ONLY. It is different to the actual circuit shown in the SYSTEM CIRCUITS SECTION.

Black
[D]
K CONNECTOR LIST
J4 K1 K2 L1
L2 L3 L4 M1 M2 M3
M4 N1 N2 O1 O2
Dark Gray
Gray
Dark Gray
BlackGrayGray
ABB
AABCCCDD DD
A
AA AA AAA 112 12
11
21
2
123
6 7 8 9 101112
45
7
12
3456 8
43 21
123 234
8910
56
1
712 11
[A]
[C]
[B]
J3
12 12
678
12 A
AA AAA ABB
AABCCCDD DD
I14 I15 I16 J1 J2
Dark Gray Gray Black
2004 COROLLA (EWD533U)
10
B HOW TO USE THIS MANUAL
[A] : Indicates connector to be connected to a part. (The numeral indicates the pin No.)
[B] : Junction Connector
Indicates a connector which is connected to a short terminal.
Junction Connector
Short Terminal
Same Color
Junction connector in this manual include a short terminal which is
connected to a number of wire harnesses. Always perform
inspection with the short terminal installed. (When installing the
wire harnesses, the harnesses can be connected to any position
within the short terminal grouping. Accordingly, in other vehicles,
the same position in the short terminal may be connected to a wire
harness from a different part.)
Wire harness sharing the same short terminal grouping have the
same color.
[C] : Parts Code
The first letter of the code is taken from the first letter of part, and the numbers indicates its order in parts which
start with the same letter.
[D] : Connector Color
Connectors not indicated are milky white in color.

A 1
L PART NUMBER OF CONNECTORS
A/C Ambient Temp. Sensor
Code
90980–11070
Part Number
D 4 Diode (Courtesy)
Code
90980–11608
A 2 A/C Condenser Fan Motor 90980–11237 D 5 Diode (Interior Light) 90980–10962
A 3 A/C Condenser Fan Relay 90980–10940 D 6 Diode (Moon Roof) 90980–11608
A 4 A/C Condenser Fan Resistor 90980–10928
90980–11271
D 7 Door Lock Control Relay 90980–10848
A 5 A/C Magnetic Clutch
90980–11413
D 8 Door Lock Control SW LH 90980–11148
A 6 A/T Oil Temp. Sensor
90980–11151
D 9 Door Lock Control SW RH
A 7 ABS Actuator
90980–11009
Door Courtesy SW LH 90980–11097
A 8 ABS Actuator
90980–10941
Door Courtesy SW RH
A 9 ABS Speed Sensor Front LH
90980–11002
Door Courtesy SW Front LH
ABS Speed Sensor Front RH
90980–11856
Door Courtesy SW Front RH 90980–11156
Airbag Sensor Front LH Door Courtesy SW Rear LH
Airbag Sensor Front RH Door Courtesy SW Rear RH
A10
A11
A12
A13 Airbag Squib 90980–11194 Door Key Lock and Unlock SW LH 90980–11170
90980–11070
D10
D11
D12
D13
D14
D15
D16
D17 Door Key Lock and Unlock SW RH
Part NumberPart NamePart Name
[A] [B] [C]
2004 COROLLA (EWD533U) 11
B
[A] : Part Code
[B] : Part Name
[C] : Part Number
Toyota Part Number are indicated.
Not all of the above part numbers of the connector are established for the supply.

To Ignition SW
IG Terminal
Fuse
VoltmeterSW 1
Relay
SW 2 Solenoid
[A]
[B]
[C]
Ohmmeter
SW
Ohmmeter
Diode
Digital Type Analog Type
2004 COROLLA (EWD533U)
12
C TROUBLESHOOTING
VOLTAGE CHECK
(a) Establish conditions in which voltage is present at the check
point.
Example:
[A] – Ignition SW on
[B] – Ignition SW and SW 1 on
[C] – Ignition SW, SW 1 and Relay on (SW 2 off)
(b) Using a voltmeter, connect the negative lead to a good ground
point or negative battery terminal, and the positive lead to the
connector or component terminal.
This check can be done with a test light instead of a voltmeter.
CONTINUITY AND RESISTANCE CHECK
(a) Disconnect the battery terminal or wire so there is no voltage
between the check points.
(b) Contact the two leads of an ohmmeter to each of the check
points.
If the circuit has diodes, reverse the two leads and check
again.
When contacting the negative lead to the diode positive side
and the positive lead to the negative side, there should be
continuity.
When contacting the two leads in reverse, there should be no
continuity.
(c) Use a volt/ohmmeter with high impedance (10 kΩ/V
minimum) for troubleshooting of the electrical circuit.

To Ignition SW
IG Terminal
Test Light
RelayLight
SW 2 Solenoid
Disconnect
Short [A]
Disconnect
Disconnect
SW 1
Fuse Case
Short [B]
Short [C]
Pull Up
Press Down Press Down
Pull Up
2004 COROLLA (EWD533U) 13
C
FINDING A SHORT CIRCUIT
(a) Remove the blown fuse and disconnect all loads of the fuse.
(b) Connect a test light in place of the fuse.
(c) Establish conditions in which the test light comes on.
Example:
[A] – Ignition SW on
[B] – Ignition SW and SW 1 on
[C] – Ignition SW, SW 1 and Relay on (Connect the
Relay) and SW 2 off (or Disconnect SW 2)
(d) Disconnect and reconnect the connectors while watching the
test light.
The short lies between the connector where the test light
stays lit and the connector where the light goes out.
(e) Find the exact location of the short by lightly shaking the
problem wire along the body.
CAUTION:
(a) Do not open the cover or the case of the ECU unless
absolutely necessary. (If the IC terminals are touched,
the IC may be destroyed by static electricity.)
(b) When replacing the internal mechanism (ECU part) of
the digital meter, be careful that no part of your body or
clothing comes in contact with the terminals of leads
from the IC, etc. of the replacement part (spare part).
DISCONNECTION OF MALE AND FEMALE
CONNECTORS
To pull apart the connectors, pull on the connector itself, not
the wire harness.
HINT: Check to see what kind of connector you are
disconnecting before pulling apart.

10
3
0.2
1
1
(mm)
Reference:
Tool
Up
Example:
(Case 1)
Terminal Retainer
Terminal Retainer
[Retainer at Full Lock Position]
[Retainer at Temporary Lock Position]
Stopper Terminal
Retainer
Secondary
Locking Device
Example:
(Case 2)
2004 COROLLA (EWD533U)
14
C TROUBLESHOOTING
HOW TO REPLACE TERMINAL
(with terminal retainer or secondary locking device)
1. PREPARE THE SPECIAL TOOL
HINT: To remove the terminal from the connector, please
construct and use the special tool or like object shown on
the left.
2. DISCONNECT CONNECTOR
3. DISENGAGE THE SECONDARY LOCKING DEVICE OR
TERMINAL RETAINER.
(a) Locking device must be disengaged before the terminal
locking clip can be released and the terminal removed from
the connector.
(b) Use a special tool or the terminal pick to unlock the secondary
locking device or terminal retainer.
NOTICE:
Do not remove the terminal retainer from connector body.
[A] For Non–Waterproof Type Connector
HINT : The needle insertion position varies according to the
connector’s shape (number of terminals etc.), so
check the position before inserting it.
”Case 1”
Raise the terminal retainer up to the temporary lock
position.
”Case 2”
Open the secondary locking device.

Tool
Tab
Tab
Terminal
Retainer
Access Hole
( Mark)
Tool
Tool
[Female]
Example:
[Male]
(Case 1)
[Male] [Female]
Retainer
at Full Lock Position
Retainer
at Temporary Lock Position
Terminal Retainer
[Male] Press Down [Female]
Press Down
Tool
Tool
Example:
(Case 2)
2004 COROLLA (EWD533U) 15
C
[B] For Waterproof Type Connector
HINT: Terminal retainer color is different
according to connector body.
Example:
Terminal Retainer : Connector Body
Black or White : Gray
Black or White : Dark Gray
Gray or White : Black
”Case 1”
Type where terminal retainer is pulled
up to the temporary lock position (Pull
Type).
Insert the special tool into the terminal
retainer access hole (Mark) and pull
the terminal retainer up to the
temporary lock position.
HINT: The needle insertion position varies
according to the connector’s shape
(Number of terminals etc.), so check
the position before inserting it.
”Case 2”
Type which cannot be pulled as far as
Power Lock insert the tool straight into
the access hole of terminal retainer as
shown.

Retainer at
Full Lock Position
[Male] [Female]
Retainer at
Temporary Lock Position
Locking Lug
Tool
2004 COROLLA (EWD533U)
16
C TROUBLESHOOTING
Push the terminal retainer down to the temporary lock position.
(c) Release the locking lug from terminal and pull the terminal out
from rear.
4. INSTALL TERMINAL TO CONNECTOR
(a) Insert the terminal.
HINT:
1. Make sure the terminal is positioned correctly.
2. Insert the terminal until the locking lug locks firmly.
3. Insert the terminal with terminal retainer in the temporary lock
position.
(b) Push the secondary locking device or terminal retainer in to
the full lock position.
5. CONNECT CONNECTOR

∗The titles given inside the components are the names of the terminals (terminal codes) and are not treated as being
abbreviations.
2004 COROLLA (EWD533U) 17
ABBREVIATIONS D
ABBREVIATIONS
The following abbreviations are used in this manual.
A/C = Air Conditioning
A/T = Automatic Transaxle
ABS = Anti–Lock Brake System
ECU = Electronic Control Unit
ESA = Electronic Spark Advance
EVAP = Evaporative Emission
IAC = Idle Air Control
IC = Integrated Circuit
J/B = Junction Block
LED = Light Emitting Diode
LH = Left–Hand
M/T = Manual Transaxle
O/D = Overdrive
R/B = Relay Block
RH = Right–Hand
SFI = Sequential Multiport Fuel Injection
SRS = Supplemental Restraint System
SW = Switch
TEMP. = Temperature
TVIP = TOYOTA Vehicle Intrusion Protection
VSV = Vacuum Switching Valve
VVT = Variable Valve Timing
w/ = With
w/o = Without

2004 COROLLA (EWD533U)
18
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, ZENER
A 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.
FUSE
A 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

2004 COROLLA (EWD533U) 19
E
RELAY
Basically, an electrically operated
switch which may be normally
closed (1) or open (2).
Current flow through a small coil
creates a magnetic field which either
opens or closes an attached switch.
1. NORMALLY
CLOSED
2. NORMALLY
OPEN SWITCH, MANUALOpens and closes
iitthb
SPEAKER
An electromechanical device which
creates sound waves from current
flow.
RELAY, DOUBLE THROW
A relay which passes current
through one set of contacts or the
other.
circuits, thereby
stopping (1) or
allowing (2) current
flow.
1. NORMALLY
OPEN
2. NORMALLY
CLOSED
RESISTOR
An electrical component with a fixed
resistance, placed in a circuit to
reduce voltage to a specific value.
SWITCH, DOUBLE THROW
A switch which continuously passes
current through one set of contacts
or the other.
RESISTOR, TAPPED
A resistor which supplies two or
more different non adjustable
resistance values.
SWITCH, IGNITION
A key operated switch with several
positions which allows various
circuits, particularly the primary
ignition circuit, to become
operational.
RESISTOR, VARIABLE or RHEOSTAT
A controllable resistor with a variable
rate of resistance.
Also called a potentiometer or
rheostat.
SENSOR (Thermistor)
A resistor which varies its resistance
with temperature.
SWITCH, WIPER PARK
Automatically returns wipers to the
stop position when the wiper switch
is turned off.
(Reed Switch Type)
SENSOR, SPEED
Uses magnetic impulses to open
and close a switch to create a signal
for activation of other components.
TRANSISTOR
A solidstate device typically used as
an electronic relay; stops or passes
current depending on the voltage
applied at ”base”.
SHORT PIN
Used to provide an unbroken
connection within a junction block.
WIRES Wires are always drawn as
straight lines on wiring
diagrams.
Crossed wires (1) without a
black dot at the junction are
tj i d
(1) NOT
CONNECTED
SOLENOID
An electromagnetic coil which forms
a magnetic field when current flows,
to move a plunger, etc.
j
not joined;
crossed wires (2) with a
black dot or octagonal ( )
mark at the junction are
spliced (joined)
connections.
(2) SPLICED

2004 COROLLA (EWD533U)
20
F RELAY LOCATIONS
[Engine Compartment]
[Body]