Mitsubishi Lancer Evolution X. Manual - part 313

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-317

STEP 18. Check for open circuit and short circuit to 
ground and harness damage between No. 2 cylinder 
injector connector B-102 (terminal No. 2) and ECM 
connector B-09 (terminal No. 3).
Q: Is the harness wire in good condition?

YES : Go to Step 19.
NO :  Repair it. Then go to Step 20.

STEP 19. Using the oscilloscope, check the No. 2 cylinder 
injector.
(1) Disconnect the No. 2 cylinder injector connector B-102 and 

connect the test harness special tool MB991658 between 
the separated connectors. (All terminals should be 
connected.)

(2) Connect the oscilloscope probe to the injector side 

connector terminal No. 2.
NOTE: When measuring with the ECM side connector, dis-
connect all ECM connectors. Connect the check harness 
special tool (MB992110) between the separated connec-
tors. Then connect the oscilloscope probe to the check har-
ness connector terminal No. 3.

(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 − How to 

Cope with Intermittent Malfunctions 

P.00-15

.

NO :  Replace the ECM. When the ECM is replaced, 

register the ID code. Refer to GROUP 42B, ID Code 
Registration Necessity Judgment Table <Vehicles 
with KOS> 

P.42B-11

 or GROUP 42C, ID Codes 

Registration Judgment Table <Vehicles with WCM> 

P.42C-9

. Then go to Step 20.

STEP 20. 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 − Pattern 23 

P.13A-9

.

(2) Check the diagnostic trouble code (DTC). 
Q: Is DTC P0202 set?

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

AK604471

1 2

AB

Injector
connector

MB991658

Oscilloscope

AK604546 AB

A

Normal  waveform

A:Injector drivetime 

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-318

DTC P0203: Injector Circuit-Cylinder 3

AK704262

1

3

2

4

1

2

3
4

1

2

3 4 5 6 7 8 9 10 11 12 13 14 15 16

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

2

1

1 2 3

4 5 6

1

12 13 14 15 16 1718 19 20 2122 2324

2 3 4 5

6 7 8 9 10 11

1 2 3 4

5 6 7

15

14

13

12

11

9

8

10

1

6

4

5

9

8

10 11

13

15

14

12

16

7

2 3

INJECTOR
NO. 3

B-103

(MU802062)

A-39

MU802607

1

2

18

INJECTOR CIRCUIT-CYLINDER 3

RED-BLA

CK

RED-

BLA

CK

GREEN-RED

B-09

AC

20A

WHITE

WHITE

A-34X

MFI
RELAY

4

3

1

2

22

36

FUSIBLE LINK

OFF

ON

WHITE

WHITE

RED-

GREEN

RED-

GREEN

4

1

14

10

15

6

7

C-304

C-317

J-C (7)

C-50

A-21X

3

2

IGNITION
SWITCH (IG1)

ETACS-
ECU

INJECTOR
RELAY

OFF

ON

RELAY BOX
(ENGINE COMPARTMENT)

ENGINE CONTROL MODULE

TO ECM

BLA

CK

BLA

CK

BLA

CK

BLA

CK

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-319

.

CIRCUIT OPERATION

• The injector power is supplied from the injector 

relay (terminal No. 3).

• The ECM controls the injector by turning the 

power transistor in the ECM "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.

.

DESCRIPTIONS OF MONITOR METHODS

The ECM detects open circuit and short malfunction.

.

MONITOR EXECUTION

Continuous

.

AK704256

Connectors: A-25X, A-34X

MFI relay

Injector relay

A-34X

A-25X

AB

AK704255AB

Connector: A-39

A-39 (B)

AK704227

Connector: B-09

ECM

B-09 (GR)

AB

AK704265 AB

Connector: B-103

B-103 (GR)

Injector No. 3

AK704258 AB

Connector: C-50

C-50 (B)

AK704259AB

Connectors: C-304, C-317

ETACS-ECU

C-304

C-317

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-320

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

.

DTC SET CONDITIONS <Circuit continuity − open circuit and shorted low>

Logic Flow Chart

Check Condition

• Engine is running.

Judgement Criterion

• The supply voltage is 3 volts or less without the 

injector driving for 2 seconds.

.

Good

Malfunction

Injector voltage < = 3V

Start

Continuous

failure for 2secs

End

No

No

Yes

Yes

Yes

No

AK700479

Monitoring

condition