Mitsubishi 380. Manual - part 545

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MFI)

13A-272

DTC P0201: Injector Circuit Malfunction - Cylinder 1.

.

CIRCUIT OPERATION

• Refer to DTC P0300 - Random/Multiple Misfire- 

P.13A-330

 and Misfire Cylinder 1- 

P.13A-334

.

• 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 

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

.

AK303096

CONNECTOR: B-01

AB

B-01 (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-273

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

• No. 1 cylinder injector failed.

• Open or shorted to ground No.1cylinder injector 

circuit.

• Shorted to battery, No.1cylinder 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 
01: No. 1 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 01, 

No. 1 injector.

(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)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MFI)

13A-274

STEP 3. Check the No.1 cylinder injector resistance at 
intermediate connector B-32.
(1) Disconnect the intermediate connector B-32.

(2) Measure the resistance between terminal No. 5 and No. 9.

• Resistance should be between 10.5 and 13.5 ohms.

Q: Is the measured resistance between 10.5 and 13.5 

ohms?
YES : Go to Step 6.
NO :  Go to Step 4.

STEP 4. Check the harness connector B-01 at No. 1 
cylinder injector for damage.
Remove the intake manifold.

Q: Is the harness connector in good condition?

YES : Go to Step 5.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 12.

AK303053

3

4

5

8

9

1

2

6

7

10

CONNECTOR: B-32

HARNESS CONNECTOR:

COMPONENT SIDE

AB

B-32 (B)

1 2 3
6 7 8

4 5
9 10

AK303098

B-32 

INTERMEDIATE

CONNECTOR

AB

AK303099

M

1

2

CONNECTOR: B-01

AB

B-01 (GR)

HARNESS CONNECTOR:

COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MFI)

13A-275

STEP 5. Check the No. 1 cylinder injector B-01.
(1) Disconnect the No. 1 cylinder injector connector B-01.

(2) Measure the resistance between injector side connector 

terminal No. 1 and No. 2.

Standard value: 10.5 

− 13.5 ohms [at 20°C (68°F)]

Q: Is the measured resistance between 10.5 and 13.5 ohms 

[at 20

°C (68°F)]?

YES : Repair harness wire between intermediate connector 

B-32 (terminal No. 9) and injector connector B-01 
(terminal No. 1) and harness wire between No.1 
cylinder injector connector B-01 (terminal No. 2) 
and intermediate connector B-32 (terminal No. 5) 
because of open circuit or short circuit to ground 
or harness damage. 

Then go to Step 12.

NO :  Replace the No.1 cylinder injector. Then go to Step 

12.

AK303099

M

1

2

CONNECTOR: B-01

AB

B-01 (GR)

HARNESS CONNECTOR:

COMPONENT SIDE

AK000559

2

1

INJECTOR SIDE
CONNECTOR

AB