1986 TOYOTA SUPRA relay

11
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:
± Ignition SW on
± Ignition SW and SW 1 on
± 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.

15
TROUBLESHOOTING / ABBREVIATIONS
DISCONNECTION AND CONNECTION OF BOLT
TYPE CONNECTORS
For engine control module (engine and electronically controlled
transmission ECU) in this vehicle, connectors are used which
require a bolt built into the connector to be screwed down to
securely connect the connector.
1. Disconnect the connector
After completely loosening the bolt, the two parts of the
connector can be separated.
NOTICE:
Do not pull the wire harness when disconnecting the
connector.
2. Connect the connector
NOTICE:
Before connecting the connector, always check that the
terminals are not bent or damaged.
(a) Match the guide section of the male connector
correctly with the female connector, then press them
together.
(b) Tighten the bolt.
Make sure the connectors are completely connected,
by tightening the bolt until there is a clearance of less
than 1 mm (0.04 in.) between the bottom of male
connector and the end of female connector.
ABBREVIATIONS
The following abbreviations are used in this manual.
ABS = Anti±Lock Brake System O/D = Overdrive
A/C = Air Conditioning PPS = Progressive Power Steering
ACIS = Acoustic Control Induction System R/B = Relay Block
A/T = Automatic Transmission RH = Right±Hand
COMB. = Combination SFI = Sequential Multiport Fuel Injection
ECU = Electronic Control Unit SRS = Supplemental Restraint System
EFI = Electronic Fuel Injection SW = Switch
EGR = Exhaust Gas Recirculation TDCL = Total Diagnostic Communication Link
EVAP = Evaporative Emission TEMP. = Temperature
ISC = Idle Speed Control TRAC = Traction Control System
J/B = Junction Block VSV = Vacuum Switching Valve
LH = Left-Hand w/ = With
M/T = Manual Transmission w/o = Without
* The titles given inside the components are the names of the terminals (terminal codes) and are not treated
as being abbreviations.

15
ABBREVIATIONS
DISCONNECTION AND CONNECTION OF BOLT
TYPE CONNECTORS
For engine control module (engine and electronically controlled
transmission ECU) in this vehicle, connectors are used which
require a bolt built into the connector to be screwed down to
securely connect the connector.
1. Disconnect the connector
After completely loosening the bolt, the two parts of the
connector can be separated.
NOTICE:
Do not pull the wire harness when disconnecting the
connector.
2. Connect the connector
NOTICE:
Before connecting the connector, always check that the
terminals are not bent or damaged.
(a) Match the guide section of the male connector
correctly with the female connector, then press them
together.
(b) Tighten the bolt.
Make sure the connectors are completely connected,
by tightening the bolt until there is a clearance of less
than 1 mm (0.04 in.) between the bottom of male
connector and the end of female connector.
ABBREVIATIONS
The following abbreviations are used in this manual.
ABS = Anti±Lock Brake System O/D = Overdrive
A/C = Air Conditioning PPS = Progressive Power Steering
ACIS = Acoustic Control Induction System R/B = Relay Block
A/T = Automatic Transmission RH = Right±Hand
COMB. = Combination SFI = Sequential Multiport Fuel Injection
ECU = Electronic Control Unit SRS = Supplemental Restraint System
EFI = Electronic Fuel Injection SW = Switch
EGR = Exhaust Gas Recirculation TDCL = Total Diagnostic Communication Link
EVAP = Evaporative Emission TEMP. = Temperature
ISC = Idle Speed Control TRAC = Traction Control System
J/B = Junction Block VSV = Vacuum Switching Valve
LH = Left-Hand w/ = With
M/T = Manual Transmission w/o = Without
* The titles given inside the components are the names of the terminals (terminal codes) and are not treated
as being abbreviations.

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

[Engine Compartment]
18
RELAY LOCATIONS
[Instrument Panel]

20
RELAY LOCATIONS
: J/B No. 1Left Kick Panel(See Page 18)

22
RELAY LOCATIONS
2: R/B No. 2Engine Compartment Left(See Page 18)
: J/B No. 2
Engine Compartment Left(See Page 18)

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)