Mitsubishi Galant. Manual — part 158

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-313

CIRCUIT OPERATION

•

A battery positive voltage is applied on the data
link connector power terminal (terminal 16). The
ground terminals (terminal 4, 5) are grounded to
the vehicle body.

COMMENT

•

The cause is probably a defect in power supply
system (including ground) for the on-board
diagnostic test mode line.

TROUBLESHOOTING HINTS (The most likely
causes for this case:)

•

Malfunction of the data link connector.

•

Damaged harness wire.

DIAGNOSIS

STEP 1. Check the power supply voltage at data link
connector C-23.
(1) Measure voltage between terminal 16 and ground.

•

Voltage should be battery positive voltage.

Q: Is the voltage normal?

YES : Go to step 2.
NO : Check harness connectors C-66, C-78 and C-85 at

intermediate connector for damage, and repair or
replace as required. Refer to GROUP 00E, Harness
Connector Inspection(

P.00E-2

). If intermediate

connectors are in good condition, repair harness wire
between fusible link (1) and data link connector C-23
terminal 16 because of open circuit. Then confirm that
the malfunction symptom is eliminated.

STEP 2. Check the continuity at data link connector C-23.
(1) Check for the continuity between terminal 4, 5 and ground.

•

Should be less than 2 ohm.

Q: Is the continuity normal?

YES : Replace the scan tool. Then confirm that the

malfunction symptom is eliminated.

NO : Repair harness wire between data link connector C-

23 terminal 4, 5 and ground because of open circuit or
harness damage. Then confirm that the malfunction
symptom is eliminated.

AK000631AB

CONNECTOR:C-78

AK000632 AB

CONNECTOR:C-66

AKX01430

1 2 3 4

121314

6

5

7 8

16

15

11

10

9

C-23 HARNESS
SIDE CONNECTOR

AE

AKX01431

AKX01431

1 2 3 4 5 6 7 8

16

15

14

13

12

11

10

9

C-23 HARNESS
SIDE CONNECTOR

AD

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-314

INSPECTION PROCEDURE 2: Communication with PCM Only Is Not Possible.

AK000477

GRA

Y

-

RED

GRA

Y

-

RED

GRA

Y

-

RED

RED-

WHITE

RED-

WHITE

RED-

WHITE

POWERTRAIN CONTROL
MODULE(PCM)

JOINT
CONNECTOR(1)

DATA LINK
CONNECTOR

C-41
(MU803782)

C-17

C-57

C-23

84

85

1

30

33

9

10

15

12

7

98

78

71

88 89

76 77

72
79
91

73
80

74

75

81
92

8283
93

8485

94

8687

9596

90

97

7 8

5

3 4

35

34

10 11 12

2122 23 24

13 14 15

25 26 27

16

28

17

18 19 20

29

30 31

32 33

36 37

38

9

1 2

6

16

15

18

17

14

20

22

21

9

7

1 2

5

19

3

33

32

30 31

29

28

25

24

23

27

26

6

11

13

4

10

8

12

15

14

13

12

11

10

1 2 3 4 5 6 7 8
9

16

ACX02447

CONNECTOR:C-23

ACCELERATOR
PEDAL

DATA LINK
CONNECTOR

AH

AK000633 AB

CONNECTOR:C-57

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-315

CIRCUIT OPERATION

•

A diagnostic output is made from the PCM
(terminal 85) to the diagnostic output terminal
(terminal 7) of the data link connector.

•

When diagnostic test mode control terminal
(terminal 1) of the data link connector is
grounded, the PCM (terminal 84) changes to the
diagnostic test mode.

COMMENT

•

No power supply to PCM.

•

Defective ground circuit of PCM.

•

Defective PCM.

•

Improper communication line between PCM and
scan tool.

TROUBLESHOOTING HINTS (The most likely
causes for this case:)

•

Malfunction of PCM power supply circuit.

•

Malfunction of the PCM.

•

Open circuit between PCM and data link
connector.

DIAGNOSIS

STEP 1. Check connector C-41 at PCM for damage.
Q: Is the connector in good condition?

YES : Go to Step 2.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection(

P.00E-2

). Then confirm that the

malfunction symptom is eliminated.

AK000280

CONNECTOR : C-41

PCM

AY

AK000566AB

CONNECTOR:C-17

AK000280

CONNECTOR : C-41

PCM

AY

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-316

STEP 2. Check for open circuit, short circuit to ground and
harness damage between data link connector C-23
terminal 1 and PCM connector C-41 terminal 84.
NOTE: Check harness after checking intermediate connectors
C-17 and C-57. If intermediate connectors are damaged, repair
or replace them. Refer to GROUP 00E, Harness Connector
Inspection(

P.00E-2

). Then check that the malfunction is

eliminated.

Q: Is the harness wire in good condition?

YES : Go to Step 3.
NO : Repair it. Then confirm that the malfunction symptom

is eliminated.

STEP 3. Check for open circuit, short circuit to ground and
harness damage between data link connector C-23
terminal 7 and PCM connector C-41 terminal 85.
NOTE: Check harness after checking intermediate connectors
C-17 and C-57. If intermediate connectors are damaged, repair
or replace them. Refer to GROUP 00E, Harness Connector
Inspection(

P.00E-2

). Then check that the malfunction is

eliminated.

Q: Is the harness wire in good condition?

YES : Refer to, INSPECTION PROCEDURE 29

−

Power

Supply System and Ignition Switch-IG System(

P.13A-

379

).

NO : Repair it. Then confirm that the malfunction symptom

is eliminated.

ACX02447

CONNECTOR:C-23

ACCELERATOR
PEDAL

DATA LINK
CONNECTOR

AH

AK000280

CONNECTOR : C-41

PCM

AY

ACX02447

CONNECTOR:C-23

ACCELERATOR
PEDAL

DATA LINK
CONNECTOR

AH

AK000280

CONNECTOR : C-41

PCM

AY