Mitsubishi Galant (2004+). Manual - part 1051

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1021

STEP 4. Check the cooling system.
Refer to GROUP 14, Engine Cooling Diagnosis 

P.14-3

.

Q: Is the cooling system normal?

YES : Replace the PCM.
NO :  Replace it. Then confirm that the malfunction 

symptom is eliminated.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1022

INSPECTION PROCEDURE 28: Power supply system and ignition switch-IG system.

6

2 3

4 5 6

1

1

3

2

4 5

1 2 3

4 5 6

7

12

11

10

14

13

9

8

1 2

3 4 5

14

15

8 9

12 13

6 7

10 11
16 17

22

21

23 24 25

26 27 28 29

30 31 32 33 34

35 36 37 38

39 40 41 42 43

52

51

53 54 55 56

57

58 59 60 61 62

63

64 65 66 67 68 69

70

71 72 73 74 75

76

77 78 79 80 81 82

83

1

2

3

4

AK303922

BLA

CK-

WHITE

BLA

CK-ORANGE

RED-WHITE

RED

RED

RED

SKY BLUE

RED-

WHITE

RED-

WHITE

RED-

WHITE

RED-

WHITE

WHITE

BLA

CK

BATTERY

R

IG2

ST

LOCK

ACC

IG1

C-308

C-215

MU801331

IGNITION
SWITCH

2

6

1

JUNCTION  BLOCK

43

42

MFI
RELAY

B-17X

A-14

(MU802755)

1

2

4

3

52

BATTERY
BACKUP

64

51

POWER
SOURCE

BLA

CK

29

POWERTRAIN CONTROL
MODULE (PCM)

GROUNDING
CONNECTOR

B-20

B-21

5

9

20A

25

17

7.5A

RELAY
BOX

Power Supply and Ignition Switch-IG Circuit

C-214

MU801857

A-13

3

2

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1023

.

CIRCUIT OPERATION

• Battery positive voltage is applied to the MFI 

relay (terminals No. 1, No. 2).

• When the ignition switch is turned to the "ON" 

position, the battery positive voltage is applied to 
the PCM (terminal No. 43). When the battery pos-
itive voltage is applied, the PCM turns the power 
transistor in the PCM "ON" and grounds the MFI 
relay coil. With this, the MFI relay turns "ON" and 
the battery positive voltage is supplied to the 
PCM (terminals No. 51, No. 64) from the MFI 
relay (terminal No. 4).

AK303241

CONNECTORS: B-20, 21

PCM

AB

AIR CLEANER

B-20

B-21 (B)

AK303872AB

A-13 (GR)

CONNECTOR: A-13

AK303803AB

CONNECTOR: B-17X

MFI RELAY

B-17X

AK303923AB

CONNECTOR: C-308

C-308

AK303924AB

CONNECTOR: C-214

C-214

AK303925AB

CONNECTOR: C-215

C-215

AK303901AB

CONNECTOR: A-14

A-14 (GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1024

• A battery positive voltage is constantly supplied 

to the PCM (terminal No. 42) as the backup 
power.

• The PCM (terminals No. 25, No. 29) is grounded 

to the vehicle body.

.

TROUBLESHOOTING HINTS (The most likely 
causes for this code to be set are:) 

• Malfunction of the ignition switch.

• Malfunction of the MFI relay.

• Improper connector contact, open or shorted har-

ness wire.

• Disconnected PCM ground wire.

• Malfunction of the PCM.

DIAGNOSIS

STEP 1. Check harness connector B-17X at MFI relay 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.

AK303806

2

1

3

4

AB

CONNECTOR: B-17X

B-17X

RELAY BOX
TRIANGLE 
MARK

HARNESS CONNECTOR:
COMPONENT SIDE