Mitsubishi Galant 9G. Manual — part 857

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-870

STEP 2. Measure the backup power supply voltage at PCM
connector B-20 by using power plant ECU check harness
special tool MB991923.
(1) Disconnect the all PCM connectors and connect power

plant ECU check harness special tool MB991923 between
the separated connectors.

AK303092

25

21

24 23 22

29 28 27 26

34 33 32 31 30

38 37 36 35

43 42 41 40 39

CONNECTOR: B-20

B-20

PCM

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER

AK203002

25

21

24 23 22

29 28 27 26

34 33 32 31 30

38 37 36 35

43 42 41 40 39

AB

POWER PLANT ECU
CHECK HARNESS CONNECTOR

MB991923

PCM

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-871

(2) Measure the voltage between terminal No. 42 and ground.

• Voltage should be battery positive voltage.

Q: Is battery positive voltage (approximately 12 volts)

present?
YES : Go to Step 5.
NO : Go to Step 3.

STEP 3. Measure the backup power supply voltage at PCM
harness side connector B-20.
(1) Disconnect the PCM connector B-20 and measure at the

harness side.

(2) Measure the voltage between terminal No. 42 and ground.

• Voltage should be battery positive voltage.

Q: Is battery positive voltage (approximately 12 volts)

present?
YES : Go to Step 4.
NO : Repair harness wire between battery and PCM

connector B-19 (terminal No. 42) because of open
circuit or short circuit to ground. Then go to Step 6.

25

21

24 23 22

29 28 27 26

34 33 32 31 30

38 37 36 35

43 42 41 40 39

AK203003AB

POWER PLANT ECU
CHECK HARNESS
CONNECTOR

AK303092

25

21

24 23 22

29 28 27 26

34 33 32 31 30

38 37 36 35

43 42 41 40 39

CONNECTOR: B-20

B-20

PCM

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER

25

21

24 23 22

29 28 27 26

34 33 32 31 30

38 37 36 35

43 42 41 40 39

AK203004

B-20 HARNESS
CONNECTOR:
COMPONENT SIDE

AC

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-872

STEP 4. Check harness connector B-20 at PCM for
damage.
Q: Is the harness connector in good condition?

YES : Repair harness wire between battery and PCM

connector B-20 (terminal No. 42) because of harness
damage. Then go to Step 6.

NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 6.

STEP 5. Check harness connector B-20 at PCM for
damage.
Q: Is the harness connector in good condition?

YES : Replace the PCM. Then go to Step 6.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 6.

AK303092

25

21

24 23 22

29 28 27 26

34 33 32 31 30

38 37 36 35

43 42 41 40 39

CONNECTOR: B-20

B-20

PCM

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER

AK303092

25

21

24 23 22

29 28 27 26

34 33 32 31 30

38 37 36 35

43 42 41 40 39

CONNECTOR: B-20

B-20

PCM

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-873

STEP 6. Using scan tool MB991958, read the diagnostic
trouble code (DTC).

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC P1603 set?

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

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827