Mitsubishi Eclipse. Manual - part 615

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-1003

NOTE: Check harness after checking intermediate connector 
B-13. If intermediate connector is 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 : Replace the ECM or PCM. Then confirm that the 

malfunction symptom is eliminated.

NO :  Repair it. Then confirm that the malfunction symptom 

is eliminated.

INSPECTION PROCEDURE 27: Incorrect Idle Speed When the A/C is Operating (A/C Switch 2 Signal)

AK000714

BL

UE-

WHITE

BL

UE-

WHITE

ENGINE CONTROL
MODULE (ECM) <M/T>
OR
POWERTRAIN CONTROL
MODULE (PCM) <A/T>

65 <M/T>
61 <A/T>

33

AUTOMATIC COMPRESSOR CONTROLLER

C-28

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

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

C-58 <M/T>
(MU803782)

C-55 <A/T>
(MU803781)

42 43
48 49 50 51 52 53 54 55 56 57

46

45

44

58 59

60 61 62 63

64 65 66

47

41

A/C Switch 2 Signal

AK300244

CONNECTOR: C-55 <A/T>

AG

PCM

C-55 (GR)

AK300091

CONNECTOR: C-58 <M/T>

ECM

AC

C-58 (GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-1004

.

CIRCUIT OPERATION

• The ECM <M/T> or PCM <A/T> increases the 

engine idle speed by driving the IAC motor when 
the automatic compressor-ECU sends a "A/C on" 
signal to the module.

• The automatic compressor-ECU detects how the 

air conditioning is applying load to the engine, 
and converts the information to a voltage signal 
(High voltage = low load, Low voltage = high 
load). This voltage signal is called "A/C switch 2 
signal". The ECM <M/T> or PCM <A/T> receives 

this A/C switch 2 signal from the automatic com-
pressor controller through terminal No. 65 <M/T> 
or terminal No. 61 <A/T>, and determines the 
idle-up speed according to the high or low air 
conditioning load.

.

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

• Malfunction of the A/C control system.

• Open or shorted circuit, or improper connector 

contact.

• ECM <M/T> or PCM <A/T> failed. 

AK300119

CONNECTOR: C-28

AB

C-28

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-1005

DIAGNOSIS

STEP 1. Check connector C-58 at ECM <M/T> or connector 
C-55 at PCM <A/T> 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.

AK300748

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

CONNECTOR: C-58 <M/T>

AB

C-58 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE

AK300462

42

43

48

49

50

51

52

53

54

55

56

57

46 45 44

58

59

60

61

62

63

64

65

66

47

41

CONNECTOR: C-55 <A/T>

C-55 (GR)

AB

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-1006

STEP 2. Check the output voltage at ECM harness side 
connector C-58 <M/T> or PCM harness side connector 
C-55 <A/T>.
(1) Disconnect the connector C-58 <M/T> or C-55 <A/T> and 

measure at the harness side.

(2) Start the engine and run at idle.
(3) Turn the A/C switch "ON".

AK300462

42

43

48

49

50

51

52

53

54

55

56

57

46 45 44

58

59

60

61

62

63

64

65

66

47

41

CONNECTOR: C-55 <A/T>

C-55 (GR)

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AK300748

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

CONNECTOR: C-58 <M/T>

AB

C-58 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE