Mitsubishi Eclipse. Manual - part 494

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-519

STEP 10. Check for open circuit and short circuit to 
ground and harness damage between injector 
intermediate connector and ECM connector <M/T> or PCM 
connector <A/T>.

a. Check the harness wire between intermediate connector 

B-48 (terminal No. 2) and ECM connector C-51 (terminal 
No. 1) <M/T> or PCM connector C-52 (terminal No. 1) 
<A/T> when checking No. 1 cylinder.

b. Check the harness wire between intermediate connector 

B-48 (terminal No. 3) and ECM connector C-51 (terminal 
No. 24) <M/T> or PCM connector C-52 (terminal No. 24) 
<A/T> when checking No. 3 cylinder.

c. Check the harness wire between intermediate connector 

B-48 (terminal No. 4) and ECM connector C-51 (terminal 
No. 10) <M/T> or PCM connector C-52 (terminal No. 10) 
<A/T> when checking No. 5 cylinder.

Q: Is the harness wire in good condition?

YES : Go to Step 11.
NO :  Repair it. Then go to Step 12.

AK300751

1

2

3

4

CONNECTOR: B-48

AB

B-48 (B)

HARNESS CONNECTOR:
COMPONENT SIDE

AK300458

2

3

4

5

6

7

8

9

11

12

13

14

15

16

17

18

19

20

30

21

22

23

24

25

26

27

28

29

31

32

33

34

35

1

10

CONNECTOR: C-52 <A/T>

C-52 (GR)

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AK300443

2

3

4

5

6

7

8

9

11

12

13

14

15

16

17

18

19

20

30

21

22

23

24

25

26

27

28

29

31

32

33

34

35

1

10

CONNECTOR: C-51 <M/T>

C-51 (GR)

AB

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-520

STEP 11. Using the oscilloscope, check the injector.
(1) Disconnect the injector intermediate connector B-48 and 

connect the test harness special tool (MD998464) 
inbetween.

(2) Connect the oscilloscope probe to each injector 

intermediate connector terminal to oscilloscope each 
cylinder:

• Terminal 2 (black clip) when checking 1 cylinder.

• Terminal 3 (blue clip) when checking 3 cylinder.

• Terminal 4 (white clip) when checking 5 cylinder.

NOTE: When measuring with the ECM or PCM side con-
nector, connect an oscilloscope probe to the each of the fol-
lowing terminals.

.

•

ECM or PCM terminal No. 1 when checking No. 1 cylin-
der injector.

•

ECM or PCM terminal No. 24 when checking No. 3 cyl-
inder injector.

•

ECM or PCM terminal No. 10 when checking No. 5 cyl-
inder. injector.

(3) Start the engine and run at idle.
(4) Measure the waveform.

• The waveform should show a normal pattern similar to 

the illustration.

(5) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the waveform normal?

YES : It can be assumed that this malfunction is intermittent. 

Refer to GROUP 00, How to Use Troubleshooting/ 
Inspection Service Points 

P.00-6

.

NO :  Replace the ECM or PCM. Then go to Step 12.

STEP 12. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− OBD-II Drive Cycle − Procedure 6 − 

Other Monitor 

P.13B-7

.

(2) Check the diagnostic trouble code (DTC).
Q: Are DTC P0201, P0203 and P0205 sets?

YES : Retry the troubleshooting.
NO :  The inspection is complete.

AK300085

CONNECTOR: B-48

AB

B-48 (B)

AK102981

INJECTOR INTERMEDIATE
CONNECTOR

MD998464

OSCILLOSCOPE

AB

1 
3 4

2

AKX01557 AB

A

NORMAL  WAVEFORM

A:INJECTOR DRIVE TIME

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-521

DTC P0202: Injector Circuit Malfunction - Cylinder 2, DTC P0204: Injector Circuit Malfunction - 
Cylinder 4, DTC P0206: Injector Circuit Malfunction - Cylinder 6

AK101606

RED-

WHITE

YELLO

W

-RED

GREEN-YELLO

W

LIGHT GREEN

RED

RED

RED

RED-

WHITE

RED-

WHITE

RED

25

9

2

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

1

1

1

2

2

2

INJECTOR
NO. 2

B-02

B-06

B-25

INJECTOR
NO. 4

INJECTOR
NO. 6

MFI
RELAY

BATTERY

4

3

1

2

C-51 <M/T>, C-52 <A/T>
         (MU803784)

2

3 4

5 6

7 8

9

11 12 13 14 15 16 17 18 19 20

30

21 22 23

24 25

26 27 28 29

3132 33

34 35

1

10

2

1

2

1

2

1

Injector Circuit - Cylinder 2, 4, 6

3 4

1 2

A-18X

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-522

.

CIRCUIT OPERATION

• The injector power is supplied from the MFI relay 

(terminal No. 4).

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

injector by turning the power transistor in the 
ECM <M/T> or PCM <A/T> "ON" and "OFF".

.

TECHNICAL DESCRIPTION

• The amount of fuel injected by the injector is con-

trolled by the amount of continuity time the coil is 
grounded by the ECM <M/T> or PCM <A/T>.

• A surge voltage is generated when the injectors 

are driven and the current flowing to the injector 
coil is shut off.

• The ECM <M/T> or PCM <A/T> checks this 

surge voltage.

.

DESCRIPTIONS OF MONITOR METHODS
Off-surge does not occur after injector is operated.

.

MONITOR EXECUTION
Continuous

.

MONITOR EXECUTION CONDITIONS (Other 
monitor and Sensor)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• Not applicable

Sensor (The sensor below is determined to be 

normal)

• Not applicable

.

AK300088

CONNECTORS: B-02, B-06, B-25

AB

B-02 (GR)

B-06 (GR)

B-25 (GR)

AK101363AB

MFI RELAY

CONNECTOR: A-18X

AK300244

CONNECTOR: C-52 <A/T>

AC

PCM

C-52 (GR)

AK300091

CONNECTOR: C-51 <M/T>

ECM

AF

C-51 (GR)