1986 TOYOTA SUPRA turn signal

51
R9 111
Rear Turn Signal Light LH
[Rear Comb. Light LH]
R10 R11 R12 R15 R16 R17 R18 S3 S6 S7 S8 S9 S11 S12 S13 S14 S15 S16 T1 T3 T4 T5 114 102 116 111 114 102 102 102 203188
208188
20820860
64122
192184210
214210
70
11 4
150
164 82
140
159
174
184192 192 192 192 82 130 164 164 159
Stop Light LH
[Rear Comb. Light LH]
Taillight LH
[Rear Comb. Light LH]
Back±Up Light RH
[Rear Comb. Light RH]
Rear Turn Signal Light RH
[Rear Comb. Light RH]
Stop Light RH
[Rear Comb. Light RH]
Taillight RH
[Rear Comb. Light RH]
Rear Side Marker Light LH
Rear Side Marker Light RH
Rear Wiper Motor and Relay
Remote Control Mirror and
Mirror Heater LH
Remote Control Mirror and
Mirror Heater RH
Rear Window Defogger (+)
Starter
Seat Heater SW
Shift Lock ECU
Stereo Power Amplifier
Stereo Power Amplifier
Stop Light SW
Seat Heater
(for Driver's Seat)
Seat Heater
(for Passenger's Seat)
Seat Heater Relay
(for Driver's Seat)
Seat Heater Relay
(for Passenger's Seat)
Sub Heated Oxygen Sensor
(for California)
Theft Deterrent Horn
Traction Brake Actuator
Traction Pump and Motor
ABS Indicator Light
[Telltale Light LH]
(4): R/B No. 5 (See page 20)
23

53
70
VSV (for Waste Gate Valve)
V10 V8
W1
Vehicle Speed Sensor
(Speed Sensor) No. 1
(For Combination Meter)
Washer Motor
Integration Relay
Power Main Relay
Taillight Relay
A/C Magnetic Clutch Relay
EFI Main Relay
EFI No. 2 Relay
Fog Light Relay
Headlight Relay
Heater Relay
Horn Relay
Starter Relay
Diode
Rear Window Defogger Relay
Turn Signal Flasher
ABS Motor Relay
ABS Solenoid Relay
Traction Motor Relay
Traction Solenoid Relay
70
140
174
220 82
150
181
228126
203108
11 8
194136102
108
122
130228 70
82
140
15070 106 94
96
108
130228129
130 60
64
130164
220208
228111 164 164 164 164
: R/B No. 5 (See page 20)
23

70
ENGINE CONTROL (FOR 2JZ±GTE)
THE ENGINE CONTROL SYSTEM UTILIZES A MICROCOMPUTER AND MAINTAINS OVERALL CONTROL OF THE ENGINE,
TRANSMISSION ETC. AN OUTLINE OF THE ENGINE CONTROL IS GIVEN HERE.
1. INPUT SIGNALS
(1) ENGINE COOLANT TEMP. (WATER TEMP.) SIGNAL CIRCUIT
THE ENGINE COOLANT TEMP. SENSOR (EFI WATER TEMP. SENSOR) DETECTS THE ENGINE COOLANT TEMP. (WATER TEMP.)
AND HAS A BUILT±IN THERMISTOR WITH A RESISTANCE, WHICH VARIES ACCORDING TO THE ENGINE COOLANT TEMP.
(WATER TEMP.) WHICH IS INPUT INTO TERMINAL THW OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU) AS A CONTROL SIGNAL.
(2) INTAKE AIR TEMP. SIGNAL CIRCUIT
THE INTAKE AIR TEMP. SENSOR IS INSTALLED IN THE MASS AIR FLOW (AIR FLOW METER) AND DETECTS THE INTAKE AlR
TEMP. WHICH IS INPUT AS A CONTROL SIGNAL TO TERMINAL THA OF THE ENGINE CONTROL MODULE (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU).
(3) OXYGEN DENSITY SIGNAL CIRCUIT
THE OXYGEN DENSITY IN THE EXHAUST EMISSION IS DETECTED BY THE HEATED OXYGEN SENSORS SIDE AND INPUT AS A
CONTROL SIGNAL TO TERMINALS OX1, OX2 OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU).
(4) RPM SIGNAL CIRCUIT
CRANKSHAFT POSITION IS DETECTED BY THE CRANKSHAFT POSITION SENSOR. CRANKSHAFT POSITION IS INPUT AS A
CONTROL SIGNAL TO TERMINAL NE OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED
TRANSMISSION ECU).
(5) THROTTLE POSITION 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 (ENGINE AND ELECTRONICALLY CONTROLLED
TRANSMISSION ECU). WHEN THE VALVE IS COMPLETELY CLOSED, THE CONTROL SIGNAL IS INPUT INTO TERMINAL IDL1.
(6) VEHICLE SPEED CIRCUIT
THE VEHICLE SPEED IS DETECTED BY VEHICLE SPEED SENSOR (SPEED SENSOR) NO.1 INSTALLED IN THE TRANSMISSION
AND THE SIGNAL IS INPUT TO TERMINAL SP1 OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU) VIA THE COMBINATION METER.
(7) NEUTRAL POSITION SIGNAL CIRCUIT
THE PARK/NEUTRAL POSITION SW (NEUTRAL START SW) DETECTS WHETHER THE SHIFT POSITION IS IN ªNº AND ªPº OR NOT,
AND THE SIGNAL IS INPUT INTO TERMINAL NSW OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU).
(8) A/C SW SIGNAL CIRCUIT
THE OPERATING VOLTAGE OF THE A/C MAGNETIC CLUTCH IS DETECTED AND THE SIGNAL IS INPUT INTO TERMINAL ACMG
OF ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AS A CONTROL SIGNAL.
(9) BATTERY SIGNAL CIRCUIT
VOLTAGE IS CONSTANTLY APPLIED TO TERMINAL BATT OF THE ENGINE CONTROL MODULE. (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU). WITH THE IGNITION SW TURNED ON, THE VOLTAGE FOR ENGINE
CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) START±UP POWER SUPPLY IS
APPLIED TO TERMINAL +B OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED
TRANSMISSION ECU) VIA EFI MAIN RELAY.
THE CURRENT FLOWING THROUGH THE IGN FUSE FLOWS TO TERMINAL IGSW OF THE ENGINE CONTROL MODULE (ENGINE
AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU).
(10) INTAKE AIR VOLUME SIGNAL CIRCUIT
INTAKE AIR VOLUME IS DETECTED BY THE MASS AIR FLOW (AIR FLOW METER) AND THE SIGNAL IS INPUT TO TERMINAL VG
OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AS A CONTROL
SIGNAL.
(11) STOP LIGHT SW SIGNAL CIRCUIT
THE STOP LIGHT SW IS USED TO DETECT WHETHER THE VEHICLE IS BRAKING OR NOT AND THE SIGNAL IS INPUT INTO
TERMINAL STP OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AS
A CONTROL SIGNAL.
(12) STARTER SIGNAL CIRCUIT
TO CONFIRM WHETHER THE ENGINE IS CRANKING, THE VOLTAGE IS APPLIED TO THE STARTER MOTOR DURING CRANKING
IS DETECTED AND THE SIGNAL IS INPUT INTO TERMINAL STA OF THE ENGINE CONTROL MODULE (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AS A CONTROL SIGNAL.
(13) ENGINE KNOCK SIGNAL CIRCUIT
ENGINE KNOCKING IS DETECTED BY KNOCK SENSOR FRONT AND REAR SIDE AND THE SIGNAL IS INPUT INTO TERMINALS
KNK1 AND KNK2 AS A CONTROL SIGNAL.
SYSTEM OUTLINE

71
2. CONTROL SYSTEM
*SEQUENTIAL MULTIPORT FUEL INJECTION (ELECTRONIC FUEL INJECTION) SYSTEM
THE SEQUENTIAL MULTIPORT FUEL INJECTION (ELECTRONIC FUEL INJECTION) SYSTEM MONITORS THE ENGINE CONDITION
THROUGH THE SIGNALS INPUT FROM EACH SENSOR (INPUT SIGNALS FROM (1) TO (13) ETC.) TO THE ENGINE CONTROL
MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU). THE BEST FUEL INJECTION TIMING IS DECIDED
BASED ON THIS DATA AND THE PROGRAM MEMORIZED BY THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU), AND THE CONTROL SIGNAL IS OUTPUT TO TERMINALS #10, #20, #30, 40, #50 AND #60 OF
THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) TO OPERATE THE
INJECTOR (INJECT THE FUEL). THE SEQUENTIAL MULTIPORT FUEL INJECTION (ELECTRONIC FUEL INJECTION) SYSTEM
PRODUCES CONTROLS OF FUEL INJECTION OPERATION BY THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU) IN RESPONSE TO THE DRIVING CONDITIONS.
*ESA (ELECTRONIC SPARK ADVANCE) SYSTEM
THE ESA SYSTEM MONITORS THE ENGINE CONDITION THROUGH THE SIGNALS INPUT TO THE ENGINE CONTROL MODULE
(ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) FROM EACH SENSOR (INPUT SIGNALS FROM (1), (2), (4) TO
(13) ETC.). THE BEST IGNITION TIMING IS DECIDED ACCORDING TO THIS DATA AND THE MEMORIZED DATA IN THE ENGINE
CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AND THE CONTROL SIGNAL IS OUTPUT
TO TERMINALS IGT1, IGT2, IGT3, IGT4, IGT5 AND IGT6 THESE SIGNALS CONTROL THE IGNITER TO PROVIDE THE BEST IGNITION
TIMING FOR THE DRIVING CONDITIONS.
*HEATED OXYGEN SENSOR HEATER CONTROL SYSTEM
THE MAIN HEATED OXYGEN SENSOR, SUB 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 OXYGEN SENSOR TO
IMPROVE DETECTION PERFORMANCE OF THE SENSOR. THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU) EVALUATES THE SIGNALS FROM EACH SENSOR (INPUT SIGNALS FROM (1), (2), (4), (9) TO
(11) ETC.), AND OUTPUTS CURRENT TO TERMINALS HT1, HT2 TO CONTROL THE HEATER.
*IDLE AIR CONTROL (IDLE SPEED CONTROL) SYSTEM
THE IDLE AIR CONTROL (ISC) SYSTEM (STEP MOTOR TYPE) INCREASES THE ENGINE SPEED AND PROVIDES IDLING 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 (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) EVALUATE THE
SIGNALS FROM EACH SENSOR (INPUT SIGNALS FROM (1), (4), (5), (8), (9), (11) ETC.), OUTPUTS CURRENT TO TERMINALS ISC1,
ISC2, ISC3 AND ISC4 TO CONTROL THE IDLE AIR CONTROL VALVE (ISC VALVE).
*EGR CONTROL SYSTEM
THE EGR CONTROL SYSTEM DETECTS THE SIGNAL FROM EACH SENSOR (INPUT SIGNALS FROM (1), (4), (9), (10) ETC.), AND
OUTPUTS CURRENT TO TERMINAL EGR TO CONTROL THE EGR VALVE.
*FUEL PUMP CONTROL SYSTEM
THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) OUTPUTS CURRENT TO
TERMINAL FPC AND CONTROLS THE FUEL PUMP ECU AND FUEL PUMP DRIVE SPEED IN RESPONSE TO THE DRIVING
CONDITIONS.
3. DIAGNOSIS SYSTEM
WITH THE DIAGNOSIS SYSTEM, WHEN THERE IS A MALFUNCTION IN THE ENGINE CONTROL MODULE (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU) SIGNAL SYSTEM, THE MALFUNCTIONING SYSTEM IS RECORDED IN THE
MEMORY. THE MALFUNCTIONING SYSTEM CAN BE FOUND BY READING THE CODE DISPLAYED BY THE MALFUNCTION INDICATOR
LAMP (CHECK ENGINE WARNING LIGHT).
4. FAIL±SAFE SYSTEM
WHEN A MALFUNCTION HAS OCCURRED IN ANY SYSTEM, 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 (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU) MEMORY OR ELSE STOPS THE ENGINE.

82
ENGINE CONTROL (FOR 2JZ±GE)
THE ENGINE CONTROL SYSTEM UTILIZES A MICROCOMPUTER AND MAINTAINS OVERALL CONTROL OF THE ENGINE,
TRANSMISSION ETC. AN OUTLINE OF THE ENGINE CONTROL IS GIVEN HERE.
1. INPUT SIGNALS
(1) ENGINE COOLANT TEMP. (WATER TEMP.) SIGNAL CIRCUIT
THE ENGINE COOLANT TEMP. SENSOR (EFI WATER TEMP. SENSOR) DETECTS THE ENGINE COOLANT TEMP. (WATER TEMP.)
AND HAS A BUILT±IN THERMISTOR WITH A RESISTANCE, WHICH VARIES ACCORDING TO THE ENGINE COOLANT TEMP.
(WATER TEMP.) WHICH IS INPUT INTO TERMINAL THW OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU) AS A CONTROL SIGNAL.
(2) INTAKE AIR TEMP. SIGNAL CIRCUIT
THE INTAKE AIR TEMP. SENSOR IS INSTALLED IN THE VOLUME AIR FLOW (AIR FLOW METER) AND DETECTS THE INTAKE AlR
TEMP. WHICH IS INPUT AS A CONTROL SIGNAL TO TERMINAL THA OF THE ENGINE CONTROL MODULE (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU).
(3) OXYGEN DENSITY SIGNAL CIRCUIT
(EXCEPT CALIFORNIA)
THE OXYGEN DENSITY IN THE EXHAUST EMISSION IS DETECTED BY THE OXYGEN SENSOR FRONT AND REAR SIDE AND
INPUT AS A CONTROL SIGNAL TO TERMINALS OX1, OX2 OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU).
(FOR CALIFORNIA)
THE OXYGEN DENSITY IN THE EXHAUST EMISSION IS DETECTED BY THE HEATED OXYGEN SENSOR FRONT AND REAR SIDE
AND INPUT AS A CONTROL SIGNAL TO TERMINALS OX1, OX2, OX3 OF THE ENGINE CONTROL MODULE (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU).
(4) RPM SIGNAL CIRCUIT
CRANKSHAFT POSITION IS DETECTED BY THE PICK±UP COIL INSTALLED INSIDE THE DISTRIBUTOR. CRANKSHAFT POSITION
IS INPUT AS A CONTROL SIGNAL TO TERMINALS G1 AND G2 OF THE ENGINE CONTROL MODULE (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU), AND ENGINE SPEED IS INPUT TO TERMINAL NE.
(5) THROTTLE POSITION 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 (ENGINE AND ELECTRONICALLY CONTROLLED
TRANSMISSION ECU). WHEN THE VALVE IS COMPLETELY CLOSED, THE CONTROL SIGNAL IS INPUT INTO TERMINAL IDL1.
(6) VEHICLE SPEED CIRCUIT
THE VEHICLE SPEED IS DETECTED BY VEHICLE SPEED SENSOR (SPEED SENSOR) NO.1 INSTALLED IN THE TRANSMISSION
AND THE SIGNAL IS INPUT TO TERMINAL SP1 OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU) VIA THE COMBINATION METER.
(7) NEUTRAL POSITION SIGNAL CIRCUIT
THE PARK/NEUTRAL POSITION SW (NEUTRAL START SW) DETECTS WHETHER THE SHIFT POSITION IS IN ªNº OR ªPº OR NOT,
AND THE SIGNAL IS INPUT INTO TERMINAL NSW OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU).
(8) A/C SW SIGNAL CIRCUIT
THE OPERATING VOLTAGE OF THE A/C MAGNETIC CLUTCH IS DETECTED AND THE SIGNAL IS INPUT INTO TERMINAL ACMG
OF ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AS A CONTROL SIGNAL.
(9) BATTERY SIGNAL CIRCUIT
VOLTAGE IS CONSTANTLY APPLIED TO TERMINAL BATT OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU). WITH THE IGNITION SW TURNED ON, THE VOLTAGE FOR ENGINE CONTROL MODULE
(ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) START±UP POWER SUPPLY IS APPLIED TO TERMINALS
+B OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) VIA EFI MAIN
RELAY.
THE CURRENT FLOWING THROUGH THE IGN FUSE FLOWS TO TERMINAL IGSW OF THE ENGINE CONTROL MODULE (ENGINE
AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU).
(10) INTAKE AIR VOLUME SIGNAL CIRCUIT
INTAKE AIR VOLUME IS DETECTED BY THE VOLUME AIR FLOW (AIR FLOW METER) AND THE SIGNAL IS INPUT TO TERMINAL
KS OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AS A CONTROL
SIGNAL.
(11) STOP LIGHT SW SIGNAL CIRCUIT
THE STOP LIGHT SW IS USED TO DETECT WHETHER THE VEHICLE IS BRAKING OR NOT AND THE SIGNAL IS INPUT INTO
TERMINAL STP OF THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AS
A CONTROL SIGNAL.
(12) STARTER SIGNAL CIRCUIT
TO CONFIRM WHETHER THE ENGINE IS CRANKING, THE VOLTAGE IS APPLIED TO THE STARTER MOTOR DURING CRANKING
IS DETECTED AND THE SIGNAL IS INPUT INTO TERMINAL STA OF THE ENGINE CONTROL MODULE (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AS A CONTROL SIGNAL.
SYSTEM OUTLINE

83
(13) ENGINE KNOCK SIGNAL CIRCUIT
ENGINE KNOCKING IS DETECTED BY KNOCK SENSOR FRONT AND REAR SIDE AND THE SIGNAL IS INPUT INTO TERMINALS
KNK1 AND KNK2 AS A CONTROL SIGNAL.
2. CONTROL SYSTEM
*SEQUENTIAL MULTIPORT FUEL INJECTION (ELECTRONIC FUEL INJECTION) SYSTEM
THE SEQUENTIAL MULTIPORT FUEL INJECTION (ELECTRONIC FUEL INJECTION) SYSTEM MONITORS THE ENGINE CONDITION
THROUGH THE SIGNALS INPUT FROM EACH SENSOR (INPUT SIGNALS FROM (1) TO (13) ETC.) TO THE ENGINE CONTROL
MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU). THE BEST FUEL INJECTION TIMING IS DECIDED
BASED ON THIS DATA AND THE PROGRAM MEMORIZED BY THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU), AND THE CONTROL SIGNAL IS OUTPUT TO TERMINALS #10, #20, #30, 40, #50 AND #60 OF
THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) TO OPERATE THE
INJECTOR (INJECT THE FUEL). THE SEQUENTIAL MULTIPORT FUEL INJECTION (ELECTRONIC FUEL INJECTION) SYSTEM
PRODUCES CONTROLS OF FUEL INJECTION OPERATION BY THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU) IN RESPONSE TO THE DRIVING CONDITIONS.
*ESA (ELECTRONIC SPARK ADVANCE) SYSTEM
THE ESA SYSTEM MONITORS THE ENGINE CONDITION THROUGH THE SIGNALS INPUT TO THE ENGINE CONTROL MODULE
(ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) FROM EACH SENSOR (INPUT SIGNALS FROM (1), (2), (4) TO
(13) ETC.). THE BEST IGNITION TIMING IS DECIDED ACCORDING TO THIS DATA AND THE MEMORIZED DATA IN THE ENGINE
CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AND THE CONTROL SIGNAL IS OUTPUT
TO TERMINAL IGT. THIS SIGNAL CONTROLS THE IGNITER TO PROVIDE THE BEST IGNITION TIMING FOR THE DRIVING
CONDITIONS.
*HEATED OXYGEN SENSOR HEATER CONTROL SYSTEM (FOR CALIFORNIA)
THE MAIN HEATED OXYGEN SENSOR FRONT AND REAR SIDE, SUB 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
OXYGEN SENSOR TO IMPROVE DETECTION PERFORMANCE OF THE SENSOR. THE ENGINE CONTROL MODULE (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU) EVALUATES THE SIGNALS FROM EACH SENSOR (INPUT SIGNALS FROM
(1), (2), (4), (9) TO (11) ETC.), AND OUTPUTS CURRENT TO TERMINALS HT1, HT2, HT3 TO CONTROL THE HEATER.
*IDLE AIR CONTROL (IDLE SPEED CONTROL) SYSTEM
THE IDLE AIR CONTROL (ISC) SYSTEM (STEP MOTOR TYPE) INCREASES THE ENGINE SPEED AND PROVIDES IDLING 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 (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) EVALUATES THE
SIGNALS FROM EACH SENSOR (INPUT SIGNALS FROM (1), (4), (5), (8), (9), (11) ETC.), OUTPUTS CURRENT TO TERMINALS ISC1,
ISC2, ISC3 AND ISC4 TO CONTROL THE IDLE AIR CONTROL VALVE (ISC VALVE).
*EGR CONTROL SYSTEM
THE EGR CONTROL SYSTEM DETECTS THE SIGNAL FROM EACH SENSOR (INPUT SIGNALS FROM (1), (4), (9), (10) ETC.), AND
OUTPUTS CURRENT TO TERMINAL EGR TO CONTROL THE EGR VALVE.
*FUEL PUMP CONTROL SYSTEM
THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) OUTPUTS CURRENT TO
TERMINAL FPC AND CONTROLS THE FUEL PUMP ECU AND FUEL PUMP DRIVE SPEED IN RESPONSE TO THE DRIVING
CONDITIONS.
*ACIS (ACOUSTIC CONTROL INDUCTION SYSTEM)
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 (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) JUDGES THE VEHICLE
SPEED BY THE SIGNALS ((4), (5)) FROM EACH SENSOR AND OUTPUTS SIGNALS TO THE TERMINAL ACIS TO CONTROL THE VSV
(FOR INTAKE CONTROL VALVE).
3. DIAGNOSIS SYSTEM
WITH THE DIAGNOSIS SYSTEM, WHEN THERE IS A MALFUNCTION IN THE ENGINE CONTROL MODULE (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU) SIGNAL SYSTEM, THE MALFUNCTIONING SYSTEM IS RECORDED IN THE
MEMORY. THE MALFUNCTIONING SYSTEM CAN BE FOUND BY READING THE CODE DISPLAYED BY THE MALFUNCTION INDICATOR
LAMP (CHECK ENGINE WARNING LIGHT).
4. FAIL±SAFE SYSTEM
WHEN A MALFUNCTION HAS OCCURRED IN ANY SYSTEM, 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 (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU) MEMORY OR ELSE STOPS THE ENGINE.

99
VOLTAGE IS ALWAYS APPLIED FROM THE MAIN FUSE, THROUGH THE HEADLIGHT RELAY (COIL SIDE) TO TERMINAL 5 OF THE
DAYTIME RUNNING LIGHT RELAY (MAIN), TERMINAL 6 OF INTEGRATION RELAY, TERMINAL 14 OF DIMMER SW, DIMMER RELAY
(DAYTIME RUNNING LIGHT RELAY NO. 2) (COIL SIDE), TO TERMINAL 17 OF THE DAYTIME RUNNING LIGHT RELAY (MAIN). WHEN THE
IGNITION SW IS TURNED ON, VOLTAGE FROM THE GAUGE FUSE IS APPLIED TO TERMINAL 2 OF THE DAYTIME RUNNING LIGHT
RELAY (MAIN).
1. DAYTIME RUNNING LIGHT OPERATION
WHEN THE ENGINE STARTS, VOLTAGE FROM TERMINAL ªLº OF THE GENERATOR (ALTERNATOR) IS APPLIED TO TERMINAL 11 OF
THE DAYTIME RUNNING LIGHT RELAY (MAIN). IF THE PARKING BRAKE LEVER IS PULLED UP (PARKING BRAKE SW ON) AT THIS
TIME, THE DAYTIME RUNNING LIGHT SYSTEM DOES NOT OPERATE. WHEN THE PARKING BRAKE IS RELEASED (PARKING BRAKE
SW OFF), A SIGNAL IS OUTPUT FROM TERMINAL 1 OF THE PARKING BRAKE SW TO TERMINAL 8 OF THE DAYTIME RUNNING LIGHT
RELAY (MAIN). THIS ACTIVATES THE DAYTIME RUNNING LIGHT RELAY (MAIN), TURNING ON THE DIMMER RELAY (DAYTIME
RUNNING LIGHT RELAY NO. 2). CURRENT ALSO FLOWS FROM THE MAIN FUSE TO DIMMER RELAY (DAYTIME RUNNING LIGHT
RELAY NO. 2) (POINT SIDE) " HEAD (LH±UPR) FUSE " HEADLIGHT HI LH " HEADLIGHT HI RH " TERMINAL (A)5 OF DAYTIME
RUNNING LIGHT RELAY NO. 3 " TERMINAL (A)3 " GROUND, CAUSING THE HEADLIGHTS TO LIGHT UP AT APPROX. 20 % OF THEIR
NORMAL BRIGHTNESS.
ONCE THE DAYTIME RUNNING LIGHT RELAY (MAIN) HAS BEEN ACTIVATED AND THE HEADLIGHTS LIGHT UP, THE HEADLIGHTS
REMAIN ON EVEN IF THE PARKING BRAKE LEVER IS ENGAGED AGAIN (PARKING BRAKE SW ON).
2. HEADLIGHT OPERATION
WHEN THE LIGHT CONTROL SW IS AT HEAD POSITION AND THE DIMMER SW AT LOW POSITION, CURRENT FLOWS FROM THE
HEADLIGHT RELAY (COIL SIDE) TO TERMINAL 6 OF THE INTEGRATION RELAY " TERMINAL 7 " TERMINAL 13 OF LIGHT CONTROL
SW " TERMINAL 11 " GROUND, ACTIVATING THE HEADLIGHT RELAY.
THIS CAUSES CURRENT TO FLOW FROM THE HEADLIGHT RELAY (POINT SIDE) TO THE HEAD LWR FUSE " HEADLIGHT LO "
GROUND, CAUSING THE HEADLIGHTS TO LIGHT UP AT NORMAL BRIGHTNESS. SIMULTANEOUSLY, CURRENT FLOWS FROM THE
DRL FUSE " DAYTIME RUNNING LIGHT RELAY NO. 3 (COIL SIDE) " GROUND, ACTIVATING RELAY NO. 3.
WHEN THE DIMMER SW IS AT HIGH POSITION, TERMINAL 12 OF THE DIMMER SW OUTPUTS A SIGNAL TO TERMINAL 16 OF THE
DAYTIME RUNNING LIGHT RELAY (MAIN) TO ACTIVATE IT. THIS TURNS ON DIMMER RELAY (DAYTIME RUNNING LIGHT RELAY NO. 2).
SO CURRENT FLOWS FROM DIMMER RELAY (DAYTIME RUNNING LIGHT RELAY NO. 2) (POINT SIDE) TO THE HEAD (LH±UPR) FUSE
" HEADLIGHT HI LH " DAYTIME RUNNING LIGHT RELAY NO. 3 (POINT SIDE) " GROUND, AND FROM THE HEAD (RH±UPR) FUSE "
DAYTIME RUNNING LIGHT RELAY NO. 3 (POINT SIDE) " HEADLIGHT HI RH " DAYTIME RUNNING LIGHT RELAY NO. 3 (POINT SIDE)
" GROUND, CAUSING THE HEADLIGHTS TO OPERATE AT HI.
WHEN THE DIMMER SW IS AT FLASH POSITION, CURRENT FROM THE HEADLIGHT RELAY (COIL SIDE) FLOWS TO TERMINAL 14 OF
THE DIMMER SW " TERMINAL 9 " GROUND, ACTIVATING THE RELAY. SIMULTANEOUSLY, CURRENT FROM THE HEADLIGHT RELAY
(POINT SIDE) FLOWS TO HEADLIGHT LO, LIGHTING UP HEADLIGHT LO AND ACTIVATING DAYTIME RUNNING LIGHT RELAY NO. 3.
THEN TERMINAL 12 OF THE DIMMER SW OUTPUTS A SIGNAL TO TERMINAL 16 OF THE DAYTIME RUNNING LIGHT RELAY (MAIN),
ACTIVATING THE DAYTIME RUNNING LIGHT RELAY (MAIN) SO THAT CURRENT FLOWS TO HEADLIGHT HI LIKE IT DOES FOR HIGH
POSITION. THIS CAUSES ALL HEADLIGHTS TO LIGHT UP.
D 6 DAYTIME RUNNING LIGHT RELAY (MAIN)
15±GROUND : ALWAYS APPROX. 12 VOLTS
2±GROUND : APPROX. 12 VOLTS WITH THE IGNITION SW AT ON POSITION
13±GROUND : ALWAYS CONTINUOUS
5±GROUND : APPROX. 12 VOLTS WITH THE DAYTIME RUNNING LIGHT SYSTEM
DOES NOT OPERATE OR LIGHT CONTROL SW AT OFF OR TAIL POSITION
(WITH THE CONNECTOR IS DISCONNECTED, ALWAYS APPROX. 12 VOLTS)
8±GROUND : CONTINUOUS WITH THE PARKING BRAKE LEVER RELEASED
SYSTEM OUTLINE
SERVICE HINTS

109
WITH THE IGNITION SW TURNED ON, THE CURRENT FLOWS TO TERMINAL 7 OF THE INTEGRATION RELAY THROUGH GAUGE
FUSE.
VOLTAGE IS APPLIED AT ALL TIMES TO TERMINAL (A) 5 OF THE INTEGRATION RELAY THROUGH THE TAILLIGHT RELAY COIL, AND
TO TERMINAL (A) 6 THROUGH THE HEADLIGHT RELAY COIL.
1. NORMAL LIGHTING OPERATION
(TURN TAILLIGHT ON)
WITH LIGHT CONTROL SW TURNED TO TAIL POSITION, A SIGNAL IS INPUT INTO TERMINAL (A) 4 OF THE INTEGRATION RELAY. DUE
TO THIS SIGNAL, THE CURRENT FLOWING TO TERMINAL (A) 5 OF THE RELAY FLOWS TO TERMINAL (A) 4 " TERMINAL 2 OF THE
LIGHT CONTROL SW " TERMINAL 11 " TO GROUND, AND TAILLIGHT RELAY CAUSES TAILLIGHTS TO TURN ON.
(TURN HEADLIGHT ON)
WITH LIGHT CONTROL SW TURNED TO HEAD POSITION, A SIGANL IS INPUT INTO TERMINAL (A) 4 AND (A) 7 OF THE INTEGRATION
RELAY. DUE TO THIS SIGNAL, THE CURRENT FLOWING TO TERMINAL (A) 6 OF THE RELAY FLOWS TO TERMINAL (A) 7 " TERMINAL
13 OF THE LIGHT CONTROL SW " TERMINAL 11 " TO GROUND IN THE HEADLIGHT CIRCUIT, AND CAUSES TAILLIGHT AND
HEADLIGHT RELAY TO TURN THE LIGHTS ON. THE TAILLIGHT CIRCUIT IS SAME AS ABOVE.
2. LIGHT AUTO TURN OFF OPERATION
WITH LIGHT ON AND THE IGNITION SW TURNED OFF (INPUT SIGNAL GOES TO TERMINAL 7 OF THE RELAY), WHEN THE DRIVER'S
DOOR IS OPENED (INPUT SIGNAL GOES TO TERMINAL 6 OF THE RELAY), THE RELAY OPERATES AND THE CURRENT IS CUT OFF
WHICH FLOWS FROM TERMINAL (A) 5 OF THE RELAY TO TERMINAL (A) 4 IN TAILLIGHT CIRCUIT AND FROM TERMINAL (A) 6 TO
TERMINAL (A) 7 IN HEADLIGHT CIRCUIT.
AS A RESULT, ALL LIGHTS ARE TURNED OFF AUTOMATICALLY.
HEADLIGHT RELAY
2 1± : CLOSED WITH LIGHT CONTROL SW AT HEAD POSITION OR DIMMER SW AT FLASH POSITION (FOR USA)
: CLOSED WITH ENGINE RUNNING AND PARKING BRAKE LEVER RELEASED (FOR CANADA)
TAILLIGHT RELAY
3±5 : CLOSED WITH LIGHT CONTROL SW AT TA I L OR HEAD POSITION
D10 DOOR COURTESY SW LH
3±2 : CLOSED WITH LH DOOR OPEN
I20(A) INTEGRATION RELAY
7±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
6±GROUND : CONTINUOUS WITH LH DOOR OPEN
1±GROUND : ALWAYS APPROX. 12 VOLTS
(A) 5±GROUND : ALWAYS APPROX. 12 VOLTS
(A) 6±GROUND : ALWAYS APPROX. 12 VOLTS
(A) 7±GROUND : CONTINUOUS WITH LIGHT CONTROL SW AT HEAD POSITION
(A) 4±GROUND : CONTINUOUS WITH LIGHT CONTROL SW AT TA I L OR HEAD POSITION
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
C1328D1030I20A29
: RELAY BLOCKS
CODESEE PAGERELAY BLOCKS (RELAY BLOCK LOCATION)
222R/B NO. 2 (ENGINE COMPARTMENT LEFT
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1B20ENGINE ROOM MAIN WIRE AND J/B NO. 1 (LEFT KICK PANEL)
1I
1J20COWL WIRE AND J/B NO. 1 (LEFT KICK PANEL)
1K
20COWL WIRE AND J/B NO. 1 (LEFT KICK PANEL)
2A22BATTERY AND J/B NO. 2 (ENGINE COMPARTMENT LEFT)
SYSTEM OUTLINE
SERVICE HINTS