Mitsubishi 380. Manual - part 552

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MFI)

13A-300

STEP 7. Check harness connector B-20 at ECU for 
damage.
Q: Is the connector in good condition?

YES : Go to Step 8.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 10.

STEP 8. Check for open circuit and short circuit to ground 
and harness damage between No. 4 cylinder injector 
connector B-27 (terminal No. 2) and ECU connector B-20 
(terminal No. 35).
Q: Is the harness wire in good condition?

YES : Go to Step 9.
NO :  Repair it. Then go to Step 10.

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

AK303110

M

1

2

CONNECTOR: B-27

B-27 (GR)

HARNESS CONNECTOR:

COMPONENT SIDE

AB

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MFI)

13A-301

STEP 9. Using the oscilloscope, check the No. 4 cylinder 
injector.
(1) Disconnect the No. 4 cylinder injector B-27 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 ECU side connector, dis-
connect the all ECU connectors and connect check harness 
special tool (MB992044) between the separated connec-
tors. Then connect an oscilloscope probe to the check har-
ness connector terminal No. 35.

(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.00-14

.

NO :  Replace the ECU. Then go to Step 10.

STEP 10. Test the EOBD drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− EOBD Drive Cycle −

P.13A-11

.

(2) Check the diagnostic trouble code (DTC).

Q: Is DTC P0204 set?

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

AK303110

M

1

2

CONNECTOR: B-27

B-27 (GR)

HARNESS CONNECTOR:

COMPONENT SIDE

AB

AK302166

1 2

INJECTOR

CONNECTOR

MB991658

OSCILLOSCOPE

AB

AKX01557 AB

A

NORMAL  WAVEFORM

A:INJECTOR DRIVE TIME

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MFI)

13A-302

DTC P0205: Injector Circuit Malfunction - Cylinder 5.

.

CIRCUIT OPERATION

• Refer to DTC P0300 - Random/Multiple Misfire- 

P.13A-330

 and Misfire Cylinder 5- 

P.13A-342

.

• The injector power is supplied from the MPI relay 

(terminal No. 4).

• The ECU controls the injector by turning the 

power transistor in the ECU "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 ECU.

• A surge voltage is generated when the injectors 

are switched on/off.

• The ECU monitors this surge voltage.

.

DTC SET CONDITIONS <Circuit continuity 

− open circuit and shorted low>

Check Conditions

• Battery voltage is between 9.04 and 16.01vols.

• Engine speed is above 801 r/min.

Judgment Criteria

• IC internal test (open circuit, short to earth, short 

to battery). 

• MIL on after 2 drive cycles.

• Misfire present.

.

EOBD DRIVE CYCLE PATTERN

Refer to Diagnostic Function 

− EOBD Drive Cycle − 

P.13A-11

.

.

AK303112

CONNECTOR: B-04

AB

B-04 (GR)

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

AK303014

CONNECTOR: B-17X

MFI RELAY

MFI RELAY

FRONT OF VEHICLE

B-17X

AB

AK303097

CONNECTOR: B-32

AB

B-32 (B)

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MFI)

13A-303

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

• No. 5 cylinder injector failed.

• Open or shorted to ground No.5 cylinder injector 

circuit.

• Shorted to battery, No.5 cylinder injector circuit.

• Harness or connector damage.

• Refer to component locations GROUP-

70

• Refer to configuration diagrams GROUP-

80

• Refer to circuit diagrams GROUP-

90

DIAGNOSIS

Required Special Tools:

• Diagnostic Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

• MB991658: Test Harness
• MB992044: Power Plant ECU Check Harness

STEP 1. Using diagnostic tool , check actuator test item 
05: No. 5 injector.

CAUTION

To prevent damage to diagnostic tool , always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting diagnostic tool .
(1) Connect diagnostic tool to the data link connector.
(2) Start the engine and run at idle.
(3) Set diagnostic tool to the actuator testing mode for item 05 

No. 5 cylinder injectors.

(4) Warm up the engine to normal operating temperature: 80

°C 

to 95

°C (176°F to 203°F).

• The idle should become slightly rougher.

(5) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Does the idle vary or engine run "rough"?

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.00-14

.

NO :  Go to Step 2.

STEP 2. Check harness connector B-32 at intermediate 
connector for damage.
Q: Is the harness connector in good condition?

YES : Go to Step 3.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 12.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AK303053

3

4

5

8

9

1

2

6

7

10

CONNECTOR: B-32

HARNESS CONNECTOR:

COMPONENT SIDE

AB

B-32 (B)