Mitsubishi Galant. Manual — part 292

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-393

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) <3.0L>

13B-394

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.13B-

466

).

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

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-395

INSPECTION PROCEDURE 3: The Service Engine Soon/Malfunction Indicator Lamp Does Not
Illuminate Right after the Ignition Switch Is Turned to the "ON" Position.

AK000521

3

2

4 5 6

1 2 3
4 5 6

BLA

CK-

WHITE

1

BR

O

WN-

BLA

CK

BR

O

WN-

BLA

CK

BLA

CK-

WHITE

R

IG2

ST

LOCK

ACC

IG1

C-73
MU801331

IGNITION
SWITCH

C-58

2

6

6

JUNCTION
BLOCK

29

6

SERVICE ENGINE SOON/
MALFUNCTION INDICATOR LAMP

POWERTRAIN CONTROL
MODULE(PCM)

21

22

C-78
MU803457

1

6

4

5

11

10

12 13

15

17

16

14

19

18

8 9

7

20

2 3

C-17

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

C-39
(MU803784)

2

3 4

5 6

7 8

9

11 12 13 14 15 16 17 18 19 20

30

21 22 23

24 25

26 27 28 29

3132 33

34 35

1

10

24 25

21

26 27

22 23

29 30 3132

28

35 36

34

33

C-29

4 5

1

6 7

2 3

10 1112

9

15 16

14

13

C-30

8

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-396

CIRCUIT OPERATION

•

The service engine soon/malfunction indicator
lamp power is supplied from the ignition switch.

•

The PCM controls the ground of the service
engine soon/malfunction indicator lamp by
turning the power transistor in the PCM ON and
OFF.

COMMENT

•

The PCM causes the service engine soon/
malfunction indicator lamp to illuminate for 5
seconds immediately after the ignition switch is
turned to the "ON" position occurred.

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

•

Burnt-out bulb.

•

Defective service engine soon/malfunction
indicator lamp circuit.

•

Malfunction of the PCM.

DIAGNOSIS

Required Special Tool:
MB991502:Scan Tool (MUT-II)

AK000633AC

CONNECTOR:C-29

AK000631AC

CONNECTOR:C-73

AK000631AB

CONNECTOR:C-78

AK000634 AB

CONNECTOR:C-58

AK000280

CONNECTOR : C-39

PCM

AW

AK000566AB

CONNECTOR:C-17