90

ENGINE CONTROL (4A–FE)

THE ENGINE CONTROL SYSTEM UTILIZES A MICROCOMPUTER AND CONTROLS OF THE ENGINE, TRANSMISSION, ETC. ANOUTLINE OF THIS SYSTEM IS GIVEN HERE.

1. INPUT SIGNALS( 1) WATER TEMP. SIGNAL SYSTEM

THE WATER TEMP. SENSOR DETECTS THE ENGINE COOLANT TEMP. AND HAS A BUILT–IN THERMISTOR WITH A RESISTANCEWHICH VARIES ACCORDING TO THE WATER TEMP. THUS THE WATER TEMP. IS INPUT IN THE FORM OF A CONTROL SIGNALTO TERMINAL THW OF THE TCCS ECU.

( 2) INTAKE AIR TEMP. SIGNAL SYSTEMTHE INTAKE AIR TEMP. SENSOR IS DETECTS THE INTAKE AIR TEMP., WHICH IS INPUT AS A CONTROL SIGNAL TO TERMINALTHA OF THE ECU.

( 3) OXYGEN SENSOR SIGNAL SYSTEMTHE OXYGEN DENSITY IN THE EXHAUST EMISSIONS IS DETECTED AND INPUT AS A CONTROL SIGNAL TO TERMINAL OX OFTHE ECU.

( 4) RPM SIGNAL SYSTEMCRANKSHAFT POSITION AND ENGINE RPM ARE DETECTED BY THE PICK–UP COIL INSTALLED INSIDE THE DISTRIBUTOR.CRANKSHAFT POSITION IS INPUT AS A CONTROL SIGNAL TO TERMINAL G1 , OF THE ECU, AND RPM IS INPUT TO TERMINALNE.

( 5) THROTTLE SIGNAL SYSTEMTHE THROTTLE POSITION SENSOR DETECTS THE THROTTLE VALVE OPENING ANGLE, WHICH IS INPUT AS A CONTROLSIGNAL TO TERMINAL PSW OF THE ECU, OR WHEN THE VALVE IS FULLY CLOSED, TO TERMINAL IDL .

( 6) VEHICLE SPEED SIGNAL SYSTEMTHE SPEED SENSOR, INSTALLED INSIDE THE COMBINATION METER, DETECTS THE VEHICLE SPEED AND INPUTS ACONTROL SIGNAL TO TERMINAL SPD OF THE ECU.

( 7) NEUTRAL START SW SIGNAL SYSTEMTHE NEUTRAL START SW DETECTS WHETHER THE SHIFT POSITION IS IN NEUTRAL OR NOT, AND INPUTS A CONTROLSIGNAL TO TERMINAL NSW OF THE ECU.

( 8) A/C SW SIGNAL SYSTEMTHE OPERATING VOLTAGE OF THE A/C MAGNET CLUTCH IS DETECTED AND INPUT IN THE FORM OF A CONTROL SIGNAL TOTERMINAL A/C OF THE ECU.

( 9) BATTERY SIGNAL SYSTEMVOLTAGE IS CONSTANTLY APPLIED TO TERMINAL BATT OF THE ECU. WHEN THE IGNITION SW IS TURNED TO ON, VOLTAGEFOR ECU OPERATION IS APPLIED VIA THE EFI MAIN RELAY TO TERMINALS +B AND +B1 OF THE ECU.

(10) INTAKE AIR VACUUM SIGNAL SYSTEMINTAKE AIR VACUUM IS DETECTED BY THE VACUUM SENSOR AND IS INPUT AS A CONTROL SIGNAL TO TERMINAL PIM OFTHE ECU.

(11) STA SIGNAL SYSTEMTO CONFIRM THAT THE ENGINE IS CRANKING, THE VOLTAGE APPLIED TO THE STARTER MOTOR DURING CRANKING ISDETECTED AND IS INPUT AS A CONTROL SIGNAL TO TERMINAL STA OF THE ECU.

(12) ELECTRICAL LOAD SIGNAL SYSTEMTHE SIGNAL WHEN SYSTEMS SUCH AS THE REAR WINDOW DEFOGGER, WHICH CAUSE A HIGH ELECTRICAL BURDEN AREON IS INPUT TO TERMINAL ELS AS A CONTROL SIGNAL.

2. CONTROL SYSTEM

* EFI (ELECTRONIC FUEL INJECTION) SYSTEM

THE EFI SYSTEM MONITORS THE ENGINE CONDITIONS THROUGH THE SIGNALS EACH SENSOR (INPUT SIGNALS (1) TO (12))INPUT TO THE ECU. BASED ON THESE DATAS AND THE PROGRAM MEMORIZED IN THE ECU, THE MOST APPROPRIATE FUELINJECTION PERIOD IS DECIDED AND CURRENT IS OUTPUT TO TERMINALS #10 AND #20 OF THE ECU, CAUSING THE INJECTORSTO OPERATE (TO INJECT FUEL).

DURING ENGINE CRANKING (SIGNAL INPUT TO TERMINAL STA ) OR FOR APPROX. 2 SECONDS AFTER NE SIGNAL INPUT, ECUOPERATION ENERGIZES (POINT CLOSED) THE FUEL PUMP CIRCUIT INSIDE THE CIRCUIT OPENING RELAY, CAUSING THE FUELPUMP TO OPERATE.

* ESA (ELECTRONIC SPARK ADVANCE) SYSTEM

THE ESA SYSTEM MONITORS THE ENGINE CONDITIONS USING THE SIGNALS (INPUT SIGNALS (1, 4, 5, 10, 11)) INPUT TO THE ECUFROM EACH SENSOR. BASED ON THIS DATA AND THE PROGRAM MEMORIZED IN THE ECU, THE MOST APPROPRIATE IGNITIONTIMING IS DECIDED AND CURRENT IS OUTPUT TO TERMINAL IGT OF THE ECU. THIS OUTPUT CONTROLS THE IGNITER TOPRODUCE THE MOST APPROPRIATE IGNITION TIMING FOR THE DRIVING CONDITIONS.

* IDLE–UP SPEED CONTROL SYSTEM

THE IDLE–UP SYSTEM USES THE AIR CONTROL VALVE FOR IDLE–UP TO INCREASE THE RPM AND PROVIDE STABLE IDLINGWHEN THE IDLE SPEED DROPS DUE TO ELECTRICAL LOAD, ETC. THE ECU EVALUATES THE SIGNALS FROM EACH SENSOR(INPUT SIGNALS (1, 4 TI 8, 12)), CURRENT IS OUTPUT TO TERMINAL V–ISC .

SYSTEM OUTLINE

91

* EGR CUT CONTROL SYSTEM

THE EGR CUT CONTROL SYSTEM CONTROLS THE VSV (FOR EGR) BY EVALUATING THE SIGNALS FROM EACH SENSOR INPUT TOTHE ECU (INPUT SIGNALS (1, 5, 6, 9)) AND BY SENDING OUTPUT TO TERMINAL EGR OF THE ECU.

* A/C CUT CONTROL SYSTEM

WHEN THE VEHICLE SUDDENLY ACCELERATES FROM LOW ENGINE SPEED, THIS SYSTEM CUTS OFF AIR CONDITIONEROPERATION FOR FIXED PERIOD OF TIME IN RESPONSE TO THE VEHICLE SPEED, THROTTLE VALVE OPENING ANGLE ANDINTAKE MANIFOLD PRESSURE IN ORDER TO MAINTAIN ACCELERATION PERFORMANCE.

AIR CONDITIONER OPERATION IS ALSO CUT OFF WHEN THE ENGINE SPEED DROPS BELOW 500 RPM DURING IDLING, THUSPREVENTING ENGINE STALLING.

THE ECU RECEIVES INPUT SIGNALS ((4, 5, 6 AND 10)), AND OUTPUTS SIGNALS TO TERMINAL ACT.

* OVERDRIVE CONTROL SYSTEM

THE ECU CONTROLS THE OD SOLENOID OF THE AUTOMATIC TRANSAXLE IN RESPONSE TO SIGNALS FROM EACH SENSOR(INPUT SIGNALS (1, 4, 5, 6 AND 10)) IN ORDER TO MAINTAIN DRIVABILITY AND ACCELERATION PERFORMANCE.

THE ECU OUTPUTS A SIGNAL FROM TERMINAL O/D TO CONTROL THE OD SOLENOID.

3. DIAGNOSIS SYSTEMWITH THE DIAGNOSIS SYSTEM, WHEN THERE IS A MALFUNCTIONING IN THE ECU SIGNAL SYSTEM, THE MALFUNCTION SYSTEMIS RECORDED IN THE MEMORY. THE MALFUNCTIONING SYSTEM CAN BE FOUND BY READING THE DISPLAY (CODE) OF THECHECK ENGINE WARNING LIGHT.

4. FAIL–SAFE SYSTEMWHEN A MALFUNCTION OCCURS IN ANY SYSTEM, IF THERE IS A POSSIBILITY OF ENGINE TROUBLE BEING CAUSED BYCONTINUED CONTROL BASED ON THE SIGNALS FROM THAT SYSTEM, THE FAIL–SAFE SYSTEM EITHER CONTROLS THE SYSTEMBY USING DATA (STANDARD VALUES) RECORDED IN THE ECU MEMORY TO PREVENT A STALL.

92

ENGINE CONTROL (4A–FE)

IG2

IG1

AM

2

AM

1

17

5 4 1

23

1

2

M

2

1

1

2

1

2

1

2

1

2

EC IG ID BN BH

I65

I40

I69

I70

I69

I30

I69 E43

E43 E43

1E3

1B8

2A10 2C5 2B1

1E4

3C9

ID36

ID33

ID32

ID34

ID31

II112 ID212

B–O

YL–B

B

B–W

Y

G–R

B–R

B–RB–R

B–R

B–R

B–R

B

B–W

B–W

B–W

B–

W

B–W

B–R

B–R

W–B

W–B

W–B

( DX

)

( C/P

)

( LE

)

W–B

W–B

W–BB

B( M

/T)

W–B

W–B

L–B

L–B

L–B

B–R

B–O

B–O

B–O

B–O

Y Y YY

YB

–OB

–OB

–O

B–W

B–W

B–W

B–O

B

B–W

B–W

B–W

1 5

3 4

1 2

3 4

L–B

B

IGNITIONSW

I11 10AIGN

15AEFI

EFIMAIN RELAY

( W/

TH

EF

TD

ET

ER

RE

NT

SY

ST

EM

)

( W/

TH

EF

TD

ET

ER

RE

NT

SY

ST

EM

)

STARTERRELAY

S 7

TO

TH

EF

TD

ET

ER

RE

NT

EC

U

NEUTRALSTART SW(A/T)

N 1

NO

.4I1

0

NO

.1I

7

NO

.2I

8

NO

.3I

9

J/B

NO

.3

JUN

CT

ION

CO

NN

EC

TO

R

J1

CIRCUITOPENINGRELAY

C14

FU

EL

PU

MP

F8

,F

9

( ST

AT

ION

W/G

,W

/G)

( S/D

,C/P

)

( A/T

)

(M/T)

INJE

CT

OR

W–B

W–B

W–B

L–O

B–O

48

21

9

93

DE

AB

EF

BC

IF

E44

I68 I68I68

I71

I67

I68

1E6

3D10

ID22 ID28 ID21 ID211

BR BR

B–RB–R

L–B

B

B–W

Y

B–R

G–R

B–R

BR BR BR

B–R

BR

BR

BR

BR

B–R L–B

BB

B

BRR

–W

L–W

V–W B

B–W R–Y

L–W

R–W B B B

Y–BWP

B–R

B–R

B–W

R–L

R–L

B–Y

BR

LG

BR

BR

BR L

BR

BR

+B +B1

OX

W

EG

R

TH

G

PS

W E2

IDL

TH

W

TH

A

FC

SP

D

ELS

A/C

AC

T

T VF

OX

V–I

SC

ST

A

23 1

2

1

2

1

2

1

2

1

2

1

H

E

B

C

F

I

B

E

H

G

D

A 1

2

THROTTLEPOSITION SENSOR

T 2

7. 5AGAUGE

15ASTOP

INTEGRATIONRELAY

J/BNO. 3

I13

BA

TT

T1 VF E1

FPB

C 5CHECKCONNECTOR

EG

RG

AS

TEM

P.

SE

NS

OR

( FO

RC

ALI

FO

RN

IA)

EFI

WA

TE

RT

EM

P.

SE

NS

OR

OX

SE

NS

OR

( MA

IN)

E2

E1

O2

VS

V( F

OR

EG

R,

CA

LIFO

RN

IA)

V1

IN–A

IRT

EM

PS

EN

SO

RI

6

AIR

CO

NTR

OL

VA

LVE

A6

TO

A/C

AM

PLI

FIE

R

FR

OM

A/C

MA

GN

ET

CLU

TCH

RE

LAY

FR

OM

IDLE

–UP

DIO

DE

5

6

3

8

8

8

PUERTRICO

EX. C/P, PUERTRICO

C/P

C/P

EX. C/P, PUERTRICO

PUERTRICO

CH

EC

KE

NG

INE

[CO

MB

.M

ET

ER

]

C19

,C

19,

C1

9,

C19

C18

,C

18

G

PUERTRICO

EX. C/P, PUERTRICO

C/P

C/P

EX. C/P, PUERTRICO

PUERTRICO

SP

EE

DS

EN

SO

R[C

OM

B.

ME

TE

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C18

,C

18,

C1

9

C17

,C

17,

C1

7I H

8

7

6

2

2

2

H

BR

B

TCCS ECU (ENGINE ECU) TCCS ECU (ENGINE ECU)T 4 T 3

B

B–W

9

9

R–Y

109 1 2 1 20

4 13 5 12 7 8 16 10 14 11

17 16 19 3 5

8 13 3 4

12 1

(US

AM

/T)

(SEALED)

(SEALED)

( C/P

)

6

GS

TJ

TO

CO

LDS

TA

RT

INJE

CTO

RS

TAR

EIN

JEC

TO

RT

IME

SW

IEIE

94

ENGINE CONTROL (4A–FE)

I68

E41

E41

E41

EB

1

2

E1 NE G– IGF IGT

BR

B–W

Y

BR

BR

Y

BR

BR

2 12 25 24 13 26

6 2 5 4 11 3 2

22 18 4 8 21 9 7 6 15

BR

BR Y

LG–R B B W B

–Y B RR

–L

Y BR

BR

BR

BR

BR

BR

BR

Y

B–W Y

TCCS ECU (ENGINE ECU)T 3

V 4 I 1VACUUM SENSOR IIA

O/D SOLENOIDO 1

NS

W

#10

#20

E1

E01

E02

E21

VC

C

PIM G

1

NE

G–

IGF

IGT

O/D

(SEALED)

(SEALED)

( SE

ALE

D)

( SE

ALE

D)

95

EFI MAIN RELAY4–5 : CLOSED WITH IGNITION SW AT ON OR ST POSITION

C14 CIRCUIT OPENING RELAY1–2 : CLOSED WITH STARTER RUNNING

E 1 EFI WATER TEMP, SENSOR1–2 : 10–20KΩ AT (–20°C, –4°F)

4–7KΩ AT (0°C, 32°F)0.9–1.3KΩ AT (40°C, 104°F)0.4–0.7KΩ AT (60°C, 140°F)0.2–0.4KΩ AT (80°C, 176°F)

I 7, I 8, I 9, I10 INJECTOR1–2 : APPROX. 13.8Ω

TCCS ECU (ENGINE ECU) VOLTAGES AT ECU CONNECTORSBATT–E1 : 10–14 VOLTS (ALWAYS)+B –E1 : 10–14 VOLTS (IGNITION SW ON)+B1–E1 : 10–14 VOLTS (IGNITION SW ON)IDL –E2 : 4.5–5.5 VOLTS (IGNITION SW ON AND THROTTLE VALVE OPEN)PSW–E2 : 4.5–5.5 VOLTS (IGNITION SW ON AND THROTTLE VALVE FULLY CLOSED)VCC–E2 : 4.5–5.5 VOLTS (IGNITION SW ON)THA–E2 : 2.0–2.5 VOLTS (IGNITION SW ON AND INTAKE AIR TEMP. 20°C (68°F))THW–E2 : 0.4–0.7 VOLTS (IGNITION SW ON COOLANT TEMP. 80°C (176°F))STA–E1 : 6–14 VOLTS (CRANKING)NO. 10–E01, E02:10–14 VOLTS (IGNITION SW ON)NO. 20–E01, E02:10–14 VOLTS (IGNITION SW ON)IGT –E1 : 0.7–1.0 VOLTS (IDLELING)T –E1 : 10–14 VOLTS (IGNITION SW ON AND CHECK CONNECTOR TE1–E1 NOT CONNECTED)

0 VOLTS OR LESS (IGNITION SW ON AND CHECK CONNECTOR TE1–E1 CONNECTED)A/C–E1 : 5–14 VOLTS (IGNITION SW ON AND A/C SW ON)

0 VOLTS OR LESS (IGNITION SW ON A/C SW OFF)W –E1 : 0 VOLTS OR LESS (IGNITION SW ON)

10–14 VOLTS (ENGINE START)PIM–E2 : 3.3–3.9 VOLTS (IGNITION SW ON)

RESISTANCE AT ECU WIRING CONNECTOR (DISCONNECT WIRING CONNECTOR)IDL –E2 : INFINITY (THROTTLE VALVE OPEN)

0Ω (THROTTLE VALVE FULLY CLOSED)PSW–E2 : 0Ω (THROTTLE VALVE FULLY OPEN)

: INFINITY (THROTTLE VALVE FULLY CLOSED)THA–E2 : 2.3KΩ (INTAKE AIR TEMP. 20°C (68°F))THW–E2 : 0.2–0.4KΩ VOLTS (COOLANT TEMP. 80°C (176°F))GI –G– : 205–255ΩNE –G– : 205–255Ω

: PARTS LOCATION

CODE SEE PAGE CODE SEE PAGE CODE SEE PAGE

A 6 25 E 2 25 J 1 28 (C/P)

C 5 25 F 8 30 (S/D), 31 (C/P), 33 (W/G) N 1 25

C1426 (S/D, W/G), 27 (STATION W/G) F 9 32 (STATION W/G) O 1 25

C1428 (C/P) I 1 25 O 2 25

C 26 (S/D, W/G), 27 (STATION W/G) I 6 25S 7

26 (S/D, W/G), 27 (STATION W/G)

C17 F 26 (S/D, W/G), 27 (STATION W/G) I 7 25S 7

28 (C/P)C17

I 28 I 8 25 T 2 25

C18B 26 (S/D, W/G), 27 (STATION W/G) I 9 25

T 326 (S/D, W/G), 27 (STATION W/G)

C18E 26 (S/D, W/G), 27 (STATION W/G) I10 25

T 328 (C/P)

A 26 (S/D, W/G), 27 (STATION W/G)I11

26 (S/D, W/G), 27 (STATION W/G)T 4

26 (S/D, W/G), 27 (STATION W/G)

C19D 26 (S/D, W/G), 27 (STATION W/G)

I1128 (C/P)

T 428 (C/P)

C19G 28

I1326 (S/D, W/G), 27 (STATION W/G) V 1 25

H 28I13

28 (C/P) V 4 25

E 1 25 J 1 26 (S/D, W/G), 27 (STATION W/G)

: RELAY BLOCKS

CODE SEE PAGE RELAY BLOCKS (RELAY BLOCK LOCATION)

4 23 R/B NO. 4 (RIGHT KICK PANEL)

SERVICE HINTS

96

ENGINE CONTROL (4A–FE)

: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR

CODE SEE PAGE JUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)1B 18 ENGINE ROOM MAIN WIRE AND J/B NO. 1 (LEFT KICK PANEL)1E 18 COWL WIRE AND J/B NO. 1 (LEFT KICK PANEL)

2A 20 ENGINE ROOM MAIN WIRE AND J/B NO. 2 (ENGINE COMPARTMENT LEFT)

2B20 ENGINE WIRE AND J/B NO 2 (ENGINE COMPARTMENT LEFT)

2C20 ENGINE WIRE AND J/B NO. 2 (ENGINE COMPARTMENT LEFT)

3A

3C 22 COWL WIRE AND J/B NO. 3 (INSTRUMENT PANEL LEFT)3D

22 COWL WIRE AND J/B NO. 3 (INSTRUMENT PANEL LEFT)

: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS

CODE SEE PAGE JOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)

38 (C/P)

ID2 40 (S/D, W/G)ID242 (STATION W/G)

ENGINE WIRE AND COWL WIRE (INSTRUMENT PANEL CENTER)38 (C/P)

ENGINE WIRE AND COWL WIRE (INSTRUMENT PANEL CENTER)

ID3 40 (S/D, W/G)ID342 (STATION W/G)

38 (C/P)

II1 40 (S/D, W/G) FLOOR WIRE AND COWL WIRE (LEFT KICK PANEL)II142 (STATION W/G)

FLOOR WIRE AND COWL WIRE (LEFT KICK PANEL)

: GROUND POINTS

CODE SEE PAGE GROUND POINTS LOCATIONEB 36 (4A–FE) INTAKE MANIFOLDEC 36 (4A–FE) LEFT FENDER

38 (C/P)

ID 40 (S/D, W/G) LEFT KICK PANELID42 (STATION W/G)

LEFT KICK PANEL

38 (C/P)

IE 40 (S/D, W/G) HEATER CONTROL LEFTIE42 (STATION W/G)

HEATER CONTROL LEFT

IF 38 HEATER CONTROL RIGHTIG 38 (C/P) R/B NO. 4 SET BOLT

BH44 (S/D)

UNDER LEFT REAR PILLARBH48 (C/P)

UNDER LEFT REAR PILLAR

BN 46 (STATION W/G) LEFT QUARTER PANEL CENTER

: SPLICE POINTS

CODE SEE PAGE WIRE HARNESS WITH SPLICE POINTS CODE SEE PAGE WIRE HARNESS WITH SPLICE POINTS

E41 I67 42 (STATION W/G) COWL WIRE

E43 36 (4A–FE) ENGINE WIRE 38 (C/P)

E4436 (4A FE) ENGINE WIRE

I68 40 (S/D, W/G)

38 (C/P)

I6842 (STATION W/G)

I30 40 (S/D, W/G) 38 (C/P)I3042 (STATION W/G) I69 40 (S/D, W/G)

38 (C/P)

I6942 (STATION W/G)

ENGINE WIREI40 40 (S/D, W/G) 38 (C/P)

ENGINE WIREI40

42 (STATION W/G) COWL WIRE I70 40 (S/D, W/G)

38 (C/P)

COWL WIRE I7042 (STATION W/G)

I65 40 (S/D, W/G) 38 (C/P)I6542 (STATION W/G) I71 40 (S/D, W/G)

I6738 (C/P)

I7142 (STATION W/G)

I6740 (S/D, W/G)

97