Isuzu N-Series. Service manual - part 740

 Engine Control System (4JH1)    6E-11

CKP Sensor, Engine Warm Up Switch and APP Sensor

Resistor

Engine

warm up

switch

signal

Low

reference

Shield

ground

Low

reference

Engine

warm up

switch

indicator

lamp

control

APP

sensor

signal

Idle

switch

signal

5V reference

ECM

ECM

101

1

2

B-340

B-340

69

24

98

B-233

49

B-234

18

H-5

2

J-183

1

J-183

J-183

3

12

H-5

90

B-233

0.5

RED

0.5

RED

0.5

WHT

0.5

WHT

CKP

Sensor

CKP

sensor

signal

5V reference

38

57

B-234

Idle

Switch

B-1

Frame

0.85

BLK

0.5

BLK/

GRN

0.5

BLK

0.5

GRN/

BLK

0.5

GRN/

ORN

0.5

RED/

GRN

0.5

GRN/

BLK

32

B-80

APP

Sensor

1

B-80

ECM

0.5

BLK

0.5

BLK

24

4

2

0.5

L

T

 GRN/

RED

T

ail

Relay

1

B-31

0.5

BRN

5

B-31

3

6

ECM

Main Relay

46

59

0.5

BLU/

RED

0.3

BLK

0.5

BRN/

RED

0.5

BRN/

RED

Engine

W

arm Up

Switch

W/S-C

ECM

Main Relay

0.5

BRN/

RED

N6A3869E

6E-12    Engine Control System (4JH1) 

MAF, IAT and ECT Sensors

N6A3870E

Low

reference

Low

reference

MAF

sensor

signal

IA

T

sensor

signal

5V reference

5V reference

ECT

sensor

signal

5V reference

93

B-233

1

J-182

2

4

5

29

H-5

16

H-14

11

H-14

37

H-5

H-8

1

2

0.5

BLK/

PNK

0.5

BLK/

PNK

0.5

BLK/

PNK

92

6

H-8

0.5

BLK/

RED

0.5

BLK/

RED

84

3

J-182

89

B-233

0.5

BLK/

BLU

0.5

BLK/

BLU

16

H-5

0.5

GR

Y

0.5

GR

Y

0.5

GR

Y

ECM

ECM

88

83

0.5

GRN/

RED

0.5

WHT/

RED

0.5

GRN/

RED

0.5

WHT/

RED

0.5

BLU/

RED

MAF & IA

T

Sensor

1

E-16

2

E-16

ECT

Sensor

0.5

BLK/

ORN

0.5

BLK/

ORN

0.5

BLU/

RED

2

1

J-105

J-105

EGR

Solenoid

V

alve

7

H-8

97

EGR

solenoid

valve

control

(PWM)

ECM

Main Relay

 Engine Control System (4JH1)    6E-13

A/C and Glow Relay

A/C

Compressor

A/C ON

signal

relay

signal

Glow

relay

control

A/C

compressor

relay

control

Resistor

1

B-339

2

B-339

0.5

GRN/

YEL

0.5

GRN/

YEL

0.5

GRN/

YEL

0.5

BLK/

RED

0.5

BLK

2

5

X-26

X-26

A/C

Signal

Relay

3

BLK/

RED

0.3

BLK/

RED

5

2

X-20

Glow

Relay

Glow

Plug

0.85

GRN/

YEL

0.85

GRN/

YEL

0.5

WHT/

GRN

0.5

BLK

0.85

BLK

0.5

WHT/

GRN

2

5

X-24

X-24

A/C

Compressor

Relay

16

H-8

3

H-8

H-8

1

H-14

ECM

J-9

Frame

B-1

Frame

41

B-234

33

94

B-233

SBF-3

Glow

60A

4

3

X-20

1

J-122

15

4

1

4

1

Fuse & Relay Box

(Behind the Cab)

F-1

AIR CON

10A

SBF-25

HEATER

30A

0.5

BLU/

RED

0.5

GRN/

ORN

USW

JOINT2

W/S-C

0.5

PNK/

GRN

0.85

GRN/

WHT

1.25

L

T

 GRN/

BLK

0.85

BRN

5

1

4

2

X-10

X-10

A/C

Thermo

Relay

0.5

BLU/

RED

3

H-18

J-6

J-6

12

Pressure

Switch

Diode

Electro

Thermo

4

H-18

0.5BLU/RED

2

BLU

1.25

BLU

ECM

Main Relay

1

H-6

Fuse &

Relay Box

(Glove Box)

Relay Box

(Instrument

 Panel)

EGR Solenoid V

alve

PCU

Exhaust Brake

 Solenoid V

alve

Intake Throttle

 Solenoid V

alve

0.5

BLU /

RED

N6A3871E

6E-14    Engine Control System (4JH1) 

EGR Solenoid Valve, Exhaust Brake Solenoid Valve, Intake Throttle Solenoid Valve, Exhaust Brake Switch,
Clutch Switch and Brake Switch

0.5

BLU/

RED

USW

JOINT2

3

BLU/

RED

0.5

YEL

0.5

WHT/

BLK

0.5

GRN

0.5

BLU/

RED

0.5

BLU/

RED

0.5

GRN/

YEL

0.5

GRN

4

1

3

2

B-66

Brake

Switch

2

1

8

7

6

3

1

2

B-89

B-89

Clutch

Switch

ECM

EHCU

(ABS

Module)

65

Stop

Light

F-5

ST

OP

LIGHT

10A

31

ECM

Main

Relay

Glow

Relay

1

H-6

30

0.5

L

T

 GRN

0.5

BLK

2

1

J-31

J-31

40

0.5

L

T

 GRN/

WHT

0.5

BLU/

RED

2

1

J-40

J-40

95

Intake

Throttle

Solenoid

V

alve

Exhaust

Brake

Solenoid

V

alve

MAF Sensor

EGR Solenoid V

alve

A/C Compressor Relay

A/C Signal Relay

9

32

H-5

0.5

L

T

 GRN

0.5

L

T

 GRN/

WHT

B-234

0.5

L

T

 GRN/

BLU

0.5

BLU/

RED

2

1

B-69

B-69

Exhaust

Brake

Switch

64

IPC

12V

Brake

pedal

switch1

signal

Exhaust

brake

switch

signal

Clutch

switch

signal

Brake

pedal

switch2

signal

Intake

throttle

solenoid

valve

control

Exhaust

brake

solenoid

valve

control

Fuse &

Relay Box

(Glove Box)

J/C-E

PCU

Idle

Switch

Resistor

Engine

W

arm Up

Switch

8

7

10

1

1

H-14

0.5

L

T

 GRN/

WHT

0.5

L

T

 GRN/

WHT

0.5

L

T

 GRN/

BLK

0.5

L

T

 GRN/

BLK

62

32

B-234

J-177

0.5

L

T

 GRN/

BLK

0.5

L

T

 GRN/

WHT

36

40

H-5

12V

Exhaust

brake 

cut

signal

input

Exhaust

brake 

cut

signal

feedback

input

Exhaust

brake

cut

signal

feedback

output

Exhaust

brake 

cut

signal

output

0.5

L

T

 GRN/

BLU

12V

N6A3872E

Neutral

switch

signal

Resistor

B-342

B-342

0.3

BLK

0.5

BLK/

WHT

0.5

BLK/

WHT

0.5

BLK/

WHT

2

1

J-50

J-50

Neutral

Switch

9

H-8

87

B-233

W/S-C

0.5

BLU/

RED

1

2