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.
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
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, MANUAL
Opens and closes
iitth b
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 ºbaseº.
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
G ELECTRICAL WIRING ROUTING
Position of Parts in Engine Compartment
[1MZ±FE]
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 Actuator
A 5 ABS Actuator
A 6 ABS Actuator and ECU
A 7 ABS and Traction Actuator
A 8 ABS and Traction Actuator
A 9 ABS Speed Sensor Front LH
A 10 ABS Speed Sensor Front RH
A 28 Air Fuel Ratio Sensor (Bank 1 Sensor 1)
A 29 Air Fuel Ratio Sensor (Bank 2 Sensor 1)
A 30 A/C Ambient Temp. Sensor
A 31 Airbag Sensor Front LH
A 32 Airbag Sensor Front RH
B 1 Back±Up Light SW
B 2 Brake Fluid Level Warning SW
C 1 Camshaft Position Sensor
C 2 Crankshaft Position Sensor
C 3 Cruise Control Actuator
D 1 Data Link Connector 1
D 2 Daytime Running Light Resistor
D 3 Diode (A/C)E 1 EGR Gas Temp. Sensor
E 2 EGR Valve Position Sensor
E 3 Electronically Controlled Transmission Solenoid
E 5 Engine Coolant Temp. Sensor
E 6 Engine Hood Courtesy SW
F 1 Front Turn Signal Light and Parking Light LH
F 2 Front Turn Signal Light and Parking Light RH
F 3 Front Wiper Motor
F 4 Fusible Link Block
F 5 Fusible Link Block
F 6 Fusible Link Block
F 7 Fusible Link Block
F 8 Fusible Link Block
F 9 Fusible Link Block
G 1 Generator
G 2 Generator
H 1 Headlight LH
H 2 Headlight RH
H 3 Heated Oxygen Sensor (Bank 1 Sensor 1)
H 4 Heated Oxygen Sensor (Bank 2 Sensor 1)
H 5 Horn (High)
H 6 Horn (Low)
G ELECTRICAL WIRING ROUTING
Position of Parts in Engine Compartment
[5S±FE]
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 Actuator
A 5 ABS Actuator
A 6 ABS Actuator and ECU
A 9 ABS Speed Sensor Front LH
A 10 ABS Speed Sensor Front RH
A 11 Air Fuel Ratio Sensor
A 31 Airbag Sensor Front LH
A 32 Airbag Sensor Front RH
B 1 Back±Up Light SW
B 2 Brake Fluid Level Warning SW
C 1 Camshaft Position Sensor
C 2 Crankshaft Position Sensor
C 3 Cruise Control Actuator
D 1 Data Link Connector 1
D 2 Daytime Running Light ResistorE 3 Electronically Controlled Transmission Solenoid
E 4 Electronically Controlled Transmission Solenoid
E 5 Engine Coolant Temp. Sensor
E 6 Engine Hood Courtesy SW
F 1 Front Turn Signal Light and Parking Light LH
F 2 Front Turn Signal Light and Parking Light RH
F 3 Front Wiper Motor
F 4 Fusible Link Block
F 5 Fusible Link Block
F 6 Fusible Link Block
F 7 Fusible Link Block
F 8 Fusible Link Block
F 9 Fusible Link Block
G 1 Generator
G 2 Generator
H 1 Headlight LH
H 2 Headlight RH
H 3 Heated Oxygen Sensor (Bank 1 Sensor 1)
H 5 Horn (High)
H 6 Horn (Low)
G
Position of Parts in Instrument Panel
J 1 Junction Connector
J 2 Junction Connector
J 3 Junction Connector
J 4 Junction Connector
J 5 Junction Connector
J 6 Junction Connector
J 7 Junction Connector
J 8 Junction Connector
J 9 Junction Connector
J 10 Junction Connector
J 11 Junction Connector
J 12 Junction Connector
J 13 Junction Connector
J 14 Junction Connector
J 15 Junction Connector
J 16 Junction Connector
J 17 Junction Connector
J 18 Junction Connector
J 19 Junction Connector
J 20 Junction Connector
J 21 Junction Connector
J 22 Junction Connector
J 23 Junction Connector
J 24 Junction Connector
J 25 Junction Connector
J 26 Junction Connector
J 27 Junction Connector
J 28 Junction Connector
J 29 Junction Connector
J 30 Junction Connector
J 31 Junction Connector
J 32 Junction Connector
J 33 Junction ConnectorJ 34 Junction Connector
J 35 Junction Connector
J 36 Junction Connector
J 37 Junction Connector
K 3 Key Interlock Solenoid
O 2 O/D Main SW and A/T Shift Lever Illumination
P 3 Parking Brake SW
P 4 Power Outlet
R 2 Radio and Player
R 3 Radio and Player
R 4 Radio and Player
R 5 Rear Window Defogger SW
R 6 Remote Control Mirror SW
R 7 Rheostat
S 3 Shift Lock ECU
S 4 Stereo Component Amplifier
S 5 Stereo Component Amplifier
S 6 Stop Light SW
T 3 Theft Deterrent ECU
T 4 Theft Deterrent ECU
T 5 Traction Off SW
T 6 Turn Signal Flasher
T 7 Transponder Key Amplifier
U 1 Unlock Warning SW
W 6 Wireless Door Lock ECU
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 water temp. is input into TERMINAL THW of the engine control module as a control signal.
(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 OXL1, OXR1
(Except California) and OXS of the engine control module. To maintain stable detection performance by the heated
oxygen sensor, a heater is used for warming the sensor. The heater is also controlled by the engine control module
(HTL, HTR (Except California) and HTS).
(4) RPM signal circuit
Camshaft position and crankshaft position are detected by the camshaft position sensor and crankshaft position sensor.
The camshaft position is input as a control signal to TERMINAL G22+ of the engine control module, and the engine
RPM is input into TERMINAL NE+.
(5) Throttle signal circuit
The throttle position sensor detects the throttle valve opening angle as a control signal, which is input into TERMINAL
VTA1 of the engine control module.
(6) Vehicle speed signal circuit
The vehicle speed sensor, installed inside the transmission, detects the vehicle speed and inputs a control signal into
TERMINAL SPD of the engine control module.
(7) Park/Neutral position SW signal circuit
The Park/Neutral position SW detects whether the shift position is in neutral, parking or not, and inputs a control signal
into TERMINAL STA of the engine control module.
(8) A/C SW signal circuit
The A/C control assembly (Automatic A/C) or A/C Amplifier (Manual A/C) inputs the A/C operations into TERMINAL A/C
of the engine control module as a control signal.
(9) Battery signal circuit
(California or w/ engine immobiliser and/or traction control)
Voltage is always supplies to TERMINAL BATT of the engine control module.
If you turn on the ignition SW, the current goes from TERMINAL MREL of the engine control module to the EFI relay and
put on the relay, and the voltage related to the engine control module operation is supplied to TERMINAL +B of the
engine control module through the EFI relay.
(Except California or w/ engine immobiliser and/or traction control)
Voltage is constantly applied to TERMINAL BATT of the engine control module. When the ignition SW is turned on,
voltage for engine control module start±up power supply is applied to TERMINAL +B of engine control module via EFI
relay.
(10) Intake air volume signal circuit
Intake air volume is detected by the mass air flow meter and a signal is input into TERMINAL VG of the engine control
module as a control signal.
(11) NSW signal circuit
To confirm whether the engine is cranking, the voltage applied to the starter motor during cranking is detected and the
signal is input into TERMINAL NSW of the engine control module as a control signal.
(12) Engine knock signal circuit
Engine knocking is detected by the knock sensor 1 and 2, then the signals are input into TERMINALS KNKR and KNKL
of the engine control module as a control signal.
(13) Air fuel ratio signal circuit (California)
The air fuel ratio is detected and input as a control signal into TERMINALS AFL+, AFR+ of the engine control module.
SYSTEM OUTLINE
ENGINE CONTROL (1MZ±FE)
2. CONTROL SYSTEM
*SFI system
The SFI system monitors the engine condition through the signals, which are input from each sensor (Input signals (1) to
(12) ). 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, #40, #50 and #60 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 (Input signals from 1, 3, 4, 12). The best ignition timing is decided according to this data and the memorized
data in the engine control module and the control signal is output to TERMINALS IGT1, IGT2 and IGT3. This signal
controls the igniter to provide the best ignition timing for the driving conditions.
*Heated oxygen sensor heater control system
The heated oxygen sensor heater control system turns the heater on when the intake air volume is low (Temp. of
exhaust emissions is low), and warms up the heated oxygen sensor to improve detection performance of the sensor.
The engine control module evaluates the signals from each sensor (Input signals from 1, 4, 9, 10), current is output to
TERMINALS HTL, HTR and HTS, controlling the heater.
*Idle air control system
The idle air control system (Rotary solenoid type) increases the RPM and provides idle stability for fast idle±up when the
engine is cold, and when the idle speed has dropped due to electrical load and so on, the engine control module
evaluates the signals from each sensor (Input signals from 1, 4, 5, 8, 9), current is output to TERMINALS RSO and RSC
to control idle air control valve.
*EGR control system
The EGR control system detects the signal from each sensor (Input signals from 1, 4, 9, 10), and outputs current to
TERMINAL EGR to control the VSV (EGR).
The EGR valve position sensor is mounted on the EGR valve. this sensor converts the EGR valve opening height into a
voltage and sends it to the engine control module as the EGR valve position signal.
*ACIS
ACIS includes a valve in the bulkhead separating the surge tank into two parts. This valve is opened and closed in
accordance with the driving conditions to control the intake manifold length in two stages for increased engine output in
all ranges from low to high speeds.
The engine control module judges the engine speed by the signals ( (4), (5) ) from each sensor and outputs signals to
the TERMINAL ACIS to control the VSV (Intake air control).
3. DIAGNOSIS SYSTEM
With the diagnosis system, when there is a malfunction in the engine control module signal system, the malfunctioning
system is recorded in the memory.
4. FAIL±SAFE SYSTEM
When a malfunction occurs in any systems, 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.