Mitsubishi Galant (2004+). Manual - part 1221

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-577

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

STEP 1. Check harness connector B-120 at the knock 
sensor for damage.

Q: Is the harness 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 go to Step 6.

AK303120

1

2

KNOCK SENSOR

AB

CONNECTOR: B-120

B-120 (GR)

HARNESS
CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-578

STEP 2. Check the continuity at knock sensor harness 
side connector B-120.

(1) Disconnect the connector B-120 and measure at the 

harness side.

(2) Check for the continuity between terminal No. 2 and 

ground.

• Should be less than 2 ohms.

Q: Does continuity exist?

YES : Go to Step 3.
NO :  Repair an open circuit or harness damage between 

knock sensor connector B-120 (terminal No. 2) and 
ground. Then go to Step 6.

AK303120

1

2

KNOCK SENSOR

AB

CONNECTOR: B-120

B-120 (GR)

HARNESS
CONNECTOR:
COMPONENT SIDE

AK303121 AB

B-120 HARNESS
CONNECTOR: 
COMPONENT SIDE

1

2

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-579

STEP 3. Check harness connector B-21 at PCM for 
damage.

Q: Is the harness connector in good condition?

YES : Go to Step 4.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 6.

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)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-580

STEP 4. Check for open circuit, short circuit to ground and 
harness damage between knock sensor connector B-120 
(terminal No. 1) and PCM connector B-21 (terminal No. 59).

Q: Is the harness wire in good condition?

YES : Go to Step 5.
NO :  Repair it. Then go to Step 6.

AK303120

1

2

KNOCK SENSOR

AB

CONNECTOR: B-120

B-120 (GR)

HARNESS
CONNECTOR:
COMPONENT SIDE

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)