Mitsubishi Galant 9G. Manual — part 902

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1050

STEP 6. Measure the backup power supply voltage at PCM
harness side connector B-20.
(1) Disconnect the connector B-20 and measure at the harness

side.

(2) Measure the voltage between terminal No. 42 and ground.

• Voltage should be battery positive voltage.

Q: Is battery positive voltage (approximately 12 volts)

present?
YES : Go to Step 7.
NO : Repair harness wire between fusible link (9) and PCM

connector B-20 (terminal No. 42) because of short
circuit. Then confirm that the malfunction symptom is
eliminated.

AK303092

25

21

24 23 22

29 28 27 26

34 33 32 31 30

38 37 36 35

43 42 41 40 39

CONNECTOR: B-20

B-20

PCM

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER

25

21

24 23 22

29 28 27 26

34 33 32 31 30

38 37 36 35

43 42 41 40 39

AK203004

B-20 HARNESS
CONNECTOR:
COMPONENT SIDE

AD

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1051

STEP 7. Check for continuity at PCM harness side
connector B-20.
(1) Disconnect the connector B-20 and measure at the harness

side.

(2) Check for the continuity between terminals (No. 25, No. 29)

and ground.

• Should be less than 2 ohms.

Q: Does continuity exist?

YES : Go to Step 8.
NO : Check harness connector A-14 at grounding

connector for damage, and repair or replace as
required. Refer to, GROUP 00E, Harness Connector
Inspection. If grounding connector is good condition,
repair harness wire between PCM connector B-20
(terminal No. 25, No. 29) and ground because of open
circuit. Then confirm that the malfunction symptom is
eliminated.

AK303092

25

21

24 23 22

29 28 27 26

34 33 32 31 30

38 37 36 35

43 42 41 40 39

CONNECTOR: B-20

B-20

PCM

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER

25

21

24 23 22

29 28 27 26

34 33 32 31 30

38 37 36 35

43 42 41 40 39

AK203261

B-20 HARNESS
CONNECTOR:
COMPONENT SIDE

AC

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1052

STEP 8. Measure the power supply voltage at PCM harness
side connector B-21.
(1) Disconnect the connector B-21 and measure at the harness

side.

(2) Measure the voltage between terminal No. 52 and ground.

• Voltage should be battery positive voltage.

Q: Is battery positive voltage (approximately 12 volts)

present?
YES : Go to Step 9.
NO : Repair harness wire between MFI relay connector

B-17X (terminal No. 3) and PCM connector B-21
(terminal No. 52) because of open circuit. Then
confirm that the malfunction symptom is eliminated.

AK303018

55

56

54 53 52 51

57

62 61 60 59 58

63

69 68 67 66 65 64

70

75 74 73 72 71

76

82 81 80 79 78 77

83

CONNECTOR: B-21

PCM

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER

B-21 (B)

55

56

54 53 52 51

57

62 61 60 59 58

63

69 68 67 66 65 64

70

75 74 73 72 71

76

82 81 80 79 78 77

83

AK203262

B-21 HARNESS
CONNECTOR:
COMPONENT SIDE

AC

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1053

STEP 9. Measure the power supply voltage at PCM harness
side connector B-21.
(1) Disconnect the connector B-21 and measure at the harness

side.

(2) Using a jumper wire, connect terminal No. 52 to ground.

(3) Measure the voltage between terminals (No. 51, No. 64)

and ground.

• Voltage should be battery positive voltage.

Q: Is battery positive voltage (approximately 12 volts)

present?
YES : Replace the PCM. Then confirm that the malfunction

symptom is eliminated.

NO : Repair harness wire between MFI relay connector

B-17X (terminal No. 4) and PCM connector B-21
(terminals No. 51, No. 64) because of open circuit.
Then confirm that the malfunction symptom is
eliminated.

AK303018

55

56

54 53 52 51

57

62 61 60 59 58

63

69 68 67 66 65 64

70

75 74 73 72 71

76

82 81 80 79 78 77

83

CONNECTOR: B-21

PCM

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER

B-21 (B)

AK203263

55

56

54 53 52 51

57

62 61 60 59 58

63

69 68 67 66 65 64

70

75 74 73 72 71

76

82 81 80 79 78 77

83

B-21 HARNESS CONNECTOR:
COMPONENT SIDE

AC