Mitsubishi Lancer Evolution IX. Manual - part 432

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-203

Code No. P0622: Alternator FR Terminal System

OPERATION

• The energized state of the alternator field coil is 

inputted from the alternator (terminal No. 4) to the 
engine-ECU (terminal No. 52).

FUNCTION

• A signal of the power supply duty ratio for the 

alternator field coil is inputted to the engine-ECU.

• In response to the signal, the engine-ECU 

detects the alternator output current and controls 
the idling speed according to the output current 
(electric load).

TROUBLE JUDGMENT

Check Condition

• Engine speed is 50 r/min. or more.

Judgment Criterion

• Input voltage from alternator FR terminal is the 

system voltage or more for 20 seconds.

PROBABLE CAUSES

• Open circuit in alternator FR terminal circuit

• Failed engine-ECU

AK501820

M

1

2

3

4

65

43
50

42
49

41
48
60 61

64

46 47
58 59
67 68

45

56
66

52

51

44

53

62

54

63

57

55

Wire colour code
B: Black  LG: Light green  G: Green  L: Blue  W: White  Y: Yellow  SB: Sky blue  BR: Brown  O: Orange  GR: Gray
R: Red  P: Pink  V: Violet

Engine-ECU

Alternator

B-25

(MU802066)

52

W

W

B-14
5

4

Alternator FR terminal circuit

IC Voltage
regulator

AB

C-119

(MU803782)

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-204

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-14 intermediate 
connector

Q: Is the check result normal?

YES : 

Go to Step 2 .

NO : 

Repair or replace the connector.

STEP 2. Perform voltage measurement at B-14 
intermediate connector.

• Disconnect connector, and measure at male con-

nector side.

• Ignition switch: "ON"

• Voltage between terminal No. 5 and earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 6 .

NO : 

Go to Step 3 .

STEP 3. Connector check: C-119 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Go to Step 4 .

NO : 

Repair or replace the connector.

AK305035

3

4

5

8

9

1

2

6

7

10

Connector : B-14

Female side 
connector

B-14(B)

AC

AK401753

1

2 3

6

7 8

4 5

9 10

Connector : B-14

Male side 
connector

B-14(B)

AB

AK501994

65

43
50

42
49

41
48
60

61

64

46

47

58

59

67

68

45

56
66

52 51

44

53

62

54

63

57

55

AB

Connector: C-119

C-119 (GR)

C-119 (GR)

Harness side connector

<L. H. drive vehicles>

<R. H. drive vehicles>

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-205

STEP 4. Check harness between B-14 (terminal 
No. 5) intermediate connector and C-119 
(terminal No. 52) engine-ECU connector.

• Check output line for short circuit.

Q: Is the check result normal?

YES : 

Go to Step 5 .

NO : 

Repair the damaged harness wire.

STEP 5. Check the trouble symptoms.

Q: Does trouble symptom persist?

YES : 

Replace the engine-ECU.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use 

Troubleshooting/Inspection Service Points 

P.00-5

).

STEP 6. Perform voltage measurement at B-14 
intermediate connector.

• Use special tool test harness (MB991658) to con-

nect connector, and measure at pick-up harness.

• Ignition switch: "ON"

• Voltage between terminal No. 5 and earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 9 .

NO : 

Go to Step 7 .

STEP 7. Connector check: B-25 alternator 
connector

Q: Is the check result normal?

YES : 

Go to Step 8 .

NO : 

Repair or replace the connector.

AK305035

3

4

5

8

9

1

2

6

7

10

Connector : B-14

Female side 
connector

B-14(B)

AC

AK501994

65

43
50

42
49

41
48
60

61

64

46

47

58

59

67

68

45

56
66

52 51

44

53

62

54

63

57

55

AB

Connector: C-119

C-119 (GR)

C-119 (GR)

Harness side connector

<L. H. drive vehicles>

<R. H. drive vehicles>

AK305035

3

4

5

8

9

1

2

6

7

10

Connector : B-14

Female side 
connector

B-14(B)

AC

AK305036

M

2

1

3

4

Harness side 
connector

AB

Connector : B-25

B-25(GR)

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-206

STEP 8. Check harness between B-25 (terminal 
No. 4) alternator connector and B-14 (terminal 
No. 5) intermediate connector.

• Check output line for short circuit.

Q: Is the check result normal?

YES : 

Replace the alternator.

NO : 

Repair the damaged harness wire.

STEP 9. Perform voltage measurement at B-14 
intermediate connector.

• Use special tool test harness (MB991658) to con-

nect connector, and measure at pick-up harness.

• Engine: Idle after warm-up

• Transmission: Neutral

• Radiator fan: Inactive

• Voltage between terminal No. 5 and earth.

OK: Switching the headlamps to ON from 
OFF causes the voltage to fall.

Q: Is the check result normal?

YES : 

Go to Step 5 .

NO : 

Go to Step 10 .

STEP 10. Connector check: B-25 alternator 
connector 

Q: Is the check result normal?

YES : 

Go to Step 11 .

NO : 

Repair or replace the connector.

AK305036

M

2

1

3

4

Harness side 
connector

AB

Connector : B-25

B-25(GR)

AK305035

3

4

5

8

9

1

2

6

7

10

Connector : B-14

Female side 
connector

B-14(B)

AC

AK305035

3

4

5

8

9

1

2

6

7

10

Connector : B-14

Female side 
connector

B-14(B)

AC

AK305036

M

2

1

3

4

Harness side 
connector

AB

Connector : B-25

B-25(GR)