1986 TOYOTA SUPRA turn signal

ECM Power Source Circuit
CIRCUIT DESCRIPTION
When the ignition switch is turned on, battery
voltage is applied to the terminals IGSW of the
ECM, and the main relay control circuit in the
ECM sends a signal to the terminal M±REL of the
ECM, switching on the main relay. This signal
causes current to flow to the coil, closing the con-
tacts of the main relay and supplying power to the
terminal +B of the ECM.
If the ignition switch is turned off, the ECM contin-
ues to switch on the main relay for a maximum of
2 seconds for the initial setting of the IAC valve.
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±465

CIRCUIT DESCRIPTION
The IAC valve is situated on the intake chamber. Intake
air bypassing the throttle valve is directed to the IAC
valve through a passage.
A step motor is built into the IAC valve. It consists of 4
coils, a magnetic rotor, valve shaft and valve.
When current flows to the coils due to signals from the
ECM, the rotor turns and moves the valve shaft forward
or backward, changing the clearance between the
valve and the valve seat.
In this way the intake air volume bypassing the throttle
valve is regulated, controlling the engine speed.
There are 125 possible positions to which the valve can
be opened.

With the engine idling measure wave forms
between terminals ISC1, ISC2, ISC3, ISC4
and E01 of engine control module when
A/C switch ON or OFF.
HINT:
The correct waveforms are as shown.
INSPECTION USING OSCILLOSCOPE
IAC Valve Circuit
± ENGINE2JZ±GE ENGINE TROUBLESHOOTINGEG±475

METER, ANALOG
Current flow activates a magnetic
coil which causes a needle to
move, thereby providing a relative
display against a background
calibration. LED (LIGHT EMITTING DIODE)
Upon current flow, these diodes
emit light without producing the
heat of a comparable light. IGNITION COIL
Converts low±voltage DC current
into high±voltage ignition current
for firing the spark plugs. 1. SINGLE
FILAMENT
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.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. BATTERY
Stores chemical energy and
converts it into electrical energy.
Provides DC current for the auto's
various electrical circuits.
CAPACITOR (Condenser)
A small holding unit for temporary
storage of electrical voltage.
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.
DIODE
A semiconductor which allows
current flow in only one direction.
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.
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
A heavy±gauge wire placed in
high amperage circuits which
burns through on overloads,
thereby protecting the circuit.
The numbers indicate the cross±
section surface area of the wires.HORN
An electric device which sounds a
loud audible signal.
LIGHT
Current flow through a filament
causes the filament to heat up
and emit light.
METER, DIGITAL
Current flow activates one or
many LED's, LCD's, or fluorescent
displays, which provide a relative
or digital display.
MOTOR
A power unit which converts
electrical energy into mechanical
energy, especially rotary motion. CIGARETTE LIGHTER
An electric resistance heating
element.
DISTRIBUTOR, IIA
Channels high±voltage current
from the ignition coil to the
individual spark plugs.2. DOUBLE
FILAMENT HEADLIGHTS
FUEL
(for High Current Fuse or
Fusible Link.)
(for Medium Current Fuse)
M
16
GLOSSARY OF TERMS AND SYMBOLS

17
1. NORMALLY
OPENOpens and
closes circuits,
thereby
stopping (1) or
allowing (2)
current flow.
RESISTOR
An electrical component with a
fixed resistance, placed in a circuit
to reduce voltage to a specific
value.
RESISTOR, TAPPED
A resistor which supplies two or
more different non adjustable
resistance values.
SENSOR (Thermistor)
A resistor which varies its
resistance with temperature.
SHORT PIN
Used to provide an unbroken
connection within a junction block.
SOLENOID
An electromagnetic coil which
forms a magnetic field when
current flows, to move a plunger,
etc.SWITCH, DOUBLE THROW
A switch which continuously
passes current through one set
of contacts or the other.
SWITCH,
IGNITION
A key operated switch with
several positions which allows
various circuits, particularly the
primary ignition circuit, to
become operational.
Wires are always
drawn as straight lines
on wiring diagrams.
Crossed wires (1)
without a black dot at
the junction are not
joined; crossed wires
(2) with a black dot or
octagonal (
) mark at
the junction are spliced
(joined) connections. RELAY, DOUBLE THROW
A relay which passes current
through one set of contacts or the
other.
SENSOR, ANALOG 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 ªbase.º SWITCH, WIPER PARK
Automatically returns wipers to
the stop position when the wiper
switch is turned off. SWITCH, MANUAL SPEAKER
An electromechanical device
which creates sound waves from
current flow.
2. NORMALLY
CLOSED
RESISTOR, VARIABLE or
RHEOSTAT
A controllable resistor with a
variable rate of resistance.
Also called a potentiometer or
rheostat. 2. NORMALLY
OPEN RELAY
1. NORMALLY
CLOSEDBasically, 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.
(2) SPLICED WIRES
(1) NOT
CONNECTED

24
ELECTRICAL WIRING ROUTING
Position of Parts in Engine Compartment
[2JZ±GTE]
A 1 A/C Ambient Temp. Sensor E 4 Engine Coolant Temp. Sender (Water Temp. Sender)
A 2 A/C Condenser Fan Motor E 5 Engine Coolant Temp. SW (Water Temp. SW)
A 3 A/C Triple Pressure SW E 6 Engine Hood Courtesy SW
(A/C Dual and Single Pressure SW) E 7 Engine Oil Level Sensor
A 4 A/C Magnetic Clutch and Lock Sensor
A 5 A/T Fluid Temp. Sensor F 1 Front Airbag Sensor LH
A 6 ABS Actuator F 2 Front Airbag Sensor RH
A 7 ABS Actuator F 3 Front Fog Light and Parking Light LH
A 10 ABS Speed Sensor Front LH F 4 Front Fog Light and Parking Light RH
A 11 ABS Speed Sensor Front RH F 5 Front Side Marker Light LH
F 6 Front Side Marker Light RH
B 1 Back±Up Light SW (for M/T) F 7 Front Turn Signal Light LH
B 2 Brake Fluid Level Warning SW F 8 Front Turn Signal Light RH
F 9 Front Wiper Motor
C 1 Camshaft Position Sensor No. 1
C 2 Camshaft Position Sensor No. 2 G 1 Generator (Alternator)
C 3 Crankshaft Position Sensor G 2 Generator (Alternator)
C 4 Cruise Control Actuator
H 1 Headlight Hi LH
D 1 Data Link Connector 1 (Check Connector) H 2 Headlight Hi RH
D 2 Daytime Running Light Relay No. 3 H 3 Headlight Lo LH
D 3 Daytime Running Light Relay No. 3 H 4 Headlight Lo RH
H 5 Heated Oxygen Sensor (Main)
E 1 EGR Gas Temp. Sensor H 8 Horn LH
E 2 Electronically Controlled Transmission Solenoid H 9 Horn RH
E 3 Engine Coolant Temp. Sensor (EFI Water Temp. Sensor)

26
ELECTRICAL WIRING ROUTING
Position of Parts in Engine Compartment
[2JZ±GE]
A 1 A/C Ambient Temp. Sensor E 2 Electronically Controlled Transmission Solenoid
A 3 A/C Dual Pressure SW E 3 Engine Coolant Temp. Sensor (EFI Water Temp.
A 4 A/C Magnetic Clutch and Lock Sensor Sensor)
A 5 A/T Fluid Temp. Sensor E 4 Engine Coolant Temp. Sender (Water Temp.
A 6 ABS Actuator Sender)
A 7 ABS Actuator E 6 Engine Hood Courtesy SW
A 8 ABS Relay E 7 Engine Oil Level Sensor
A 9 ABS Relay
A 10 ABS Speed Sensor Front LH F 1 Front Airbag Sensor LH
A 11 ABS Speed Sensor Front RH F 2 Front Airbag Sensor RH
F 3 Front Fog Light and Parking Light LH
B 1 Back-Up Light SW (for M/T) F 4 Front Fog Light and Parking Light RH
B 2 Brake Fluid Level Warning SW F 5 Front Side Marker Light LH
F 6 Front Side Marker Light RH
C 4 Cruise Control Actuator F 7 Front Turn Signal Light LH
F 8 Front Turn Signal Light RH
D 1 Data Link Connector 1 (Check Connector) F 9 Front Wiper Motor
D 4 Distributor
G 1 Generator (Alternator)
E 1 EGR Gas Temp. Sensor G 2 Generator (Alternator)

47
197
Center Airbag Sensor
Assembly
C5 C6 C10 C11D5 C7D1 D2 D3 C13 C8 C9 C12 C14 C15 C16 186 122 186 60
70
130 64
82
220159
140
150
164
174
220
122 70
82
181
228111140
150
22022094
9611194
96106 129
94
96
102
108
122
111 126 203 174140
150
17496 96 70
140
159 82
150
164
197
70
82
164
174
197
Cigarette Lighter
Cigarette Lighter
Illumination
Clock
Clutch Start SW
Brake Warning Light
[Comb. Meter]
Combination Meter
Meter Illumination
[Comb. Meter]
Speedometer
[Comb. Meter]
Turn Signal Indicator
Light [Comb. Meter]
Combination Meter
High Beam Indicator
Light [Comb. Meter]
Turn Signal Indicator
Light [Comb. Meter]
Dimmer SW [Comb. SW]
Fog Light SW [Comb. SW]
Horn SW [Comb. SW]
Light Control SW
[Comb. Meter]
Turn Signal SW
[Comb. Meter]
Front Wiper and Washer
SW [Comb. Meter]
Rear Wiper and Washer
SW [Comb. Meter]
Cruise Control Clutch SW
Cruise Control ECU
Data Link Connector 1
(Check Connector)
Daytime Running Light
Relay No. 3
Data Link Connector 2
(TDCL)
(4): R/B No. 5 (See page 20)
23

48
POWER SOURCE (Current Flow Chart)*1: (FOR CANADA)
*2: (FOR USA)
*Page Nos. of
Related Systems
Parts
Code or
Location
CB or Fuse
Location
96
164
220
Daytime Running Light
Relay (Main)
D6
* These are the page numbers of the first page on which the related system is shown.
The part indicated is located somewhere in the system, not necessarily on the page indicated here.


7.5A HTR
7.5A IGN
7.5A RAD No. 2
7.5A ST
7.5A TURN
10A ECU±B
10A ECU±IG
10A GAUGE
10A MIR±HTR
10A PANEL
10A TAIL
15A CIG
15A SEAT±HTR
15A STOP
20A WIPER
30A DEFOG
30A DOOR
7.5A ALT±S
7.5A DOME
7.5A DRL
7.5A TRAC
15A FOG
15A HAZ±HORN
15A HEAD (LH) *2
15A HEAD (LH±LWR) *1
15A HEAD (LH±UPR) *1
15A HEAD (RH) *2
15A HEAD (RH±LWR) *1
15A HEAD (RH±UPR) *1
20A RAD No. 1
30A ABS No. 2
30A EFI No. 1
30A EFI No. 2
30A FAN
50A HTR
50A MAIN
60A ABS No. 1
60A POWERD7 D8 D10 D11 D12 E2 E4 E5 E7 E8 E9 E10 F3 F4 F5 F6 F7 F8 F9 11 870
82118 118 118 140 220 228 220 112 60
70
140 64
82
150
70
82
140
150
228102
106102
106102 102 111 111 126
Diode (for Interior Light)
Diode (for Idle±Up)
Door Courtesy SW LH
Door Courtesy SW RH
Door Key Lock and
Unlock SW LH
Electronically Controlled
Transmission Solenoid
Engine Coolant Temp. Sender
(Water Temp. Sender)
Engine Coolant Temp. SW
(Water Temp. SW)
Engine Oil Level Sensor
Electronically Controlled
Transmission Pattern
Select SW
Engine Control Module
(Engine and Electronically
Controlled Transmission
ECU)
Front Fog Light and Parking
Light LH
Front Fog Light and Parking
Light RH
Front Side Marker Light LH
Front Side Marker Light RH
Front Turn Signal Light LH
Front Turn Signal Light RH
Front Wiper Motor
[LOCATION](1): J/B No. 1 (See page 20)(2): R/B No. 2 (See page 19)(3): R/B No. 4 (See page 23)
20 22
23