Mitsubishi Galant (2004+). Manual - part 913

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-469

STEP 9. Using the oscilloscope, check the No. 1 cylinder 
injector.

(1) Disconnect the No. 1 cylinder injector connector B-01 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 PCM side connector, dis-
connect the all PCM connectors and connect check har-
ness special tool (MB991923) between the separated 
connectors. Then connect the oscilloscope probe to the 
check harness connector terminal No. 153.

(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 PCM. Then go to Step 10.

STEP 10. 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.13A-5

.

(2) Check the diagnostic trouble code (DTC). 
Q: Is DTC P0201 set?

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

M

1

2

AK303843

B-01 (GR)

CONNECTOR: B-01

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AK302166

1 2

INJECTOR
CONNECTOR

MB991658

OSCILLOSCOPE

AB

AKX01557 AB

A

NORMAL  WAVEFORM

A:INJECTOR DRIVE TIME

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-470

DTC P0202: Injector Circuit-Cylinder 2

CAUTION

If DTC P0202 has been set, TCL related DTC 
U1120 is also set. After P0202 has been diag-
nosed, don't forget to erase DTC U1120.

2

1

1

2

3

4

AK303844

121 122 123 124 125 126 127

128 129 130 131 132 133

134 135 136 137 138 139 140

141 142 143 144 145 146

147 148 149 150 151 152 153

RED

YELLOW-RED

B-17X

MFI
RELAY

INJECTOR
NO. 2

B-30

4

1

2

3

POWERTRAIN CONTROL
MODULE (PCM)

146

B-23

Injector Circuit-Cylinder 2

RED-

WHITE

RED-

WHITE

BATTERY

1

2

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-471

.

CIRCUIT OPERATION

• The injector power is supplied from the MFI relay 

(terminal No. 4).

• The PCM controls the injector by turning the 

power transistor in the PCM "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 PCM.

• A surge voltage is generated when the injectors 

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

• The PCM 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

.

AK303845

B-30 (GR)

CONNECTOR: B-30

AB

AK303803AB

CONNECTOR: B-17X

MFI RELAY

B-17X

AK303059

CONNECTOR: B-23

PCM

AB

AIR CLEANER

B-23

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-472

DTC SET CONDITIONS

Logic Flow Chart

Check Conditions

• Engine is running.

Judgment Criteria

• Injector coil surge voltage (battery positive volt-

age + 2 volts) has not been detected for 2 sec-
onds.

.

OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function 

− OBD-II Drive Cycle − 

Procedure 6 

− Other Monitor 

P.13A-5

.

.

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

• No.2 cylinder injector failed.

• Open or shorted No.2 cylinder injector circuit, 

harness damage or connector damage.

• PCM failed.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

• MB991658: Test Harness

• MB991923: Power Plant ECU Check Harness

START

END

NO

NO

NO

YES

YES

YES

MALFUNCTION

GOOD

MONITORING

CONDITIONS

CONTINUOUS

FAILURE FOR 2secs

INJ. SURGE V

< V

B

 + 2.0 V

AK302031