Mitsubishi Galant 9G. Manual — part 851

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-846

STEP 1. Measure the power supply voltage at PCM
connector B-22 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.

(2) Start the engine and run at idle.

AK303016

104

96

94

95

93 92 91

99 98 97

103 102 101 100

108 107 106 105

113 112 111 110 109

CONNECTOR: B-22

B-22 (B)

PCM

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER

AK202956

104

96

94

95

93 92 91

99 98 97

103 102 101 100

108 107 106 105

113 112 111 110 109

AB

POWER PLANT ECU
CHECK HARNESS CONNECTOR

MB991923

PCM

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-847

(3) Measure the voltage between terminal No. 110 and ground.

• Voltage should be 1 volt or less when engine is idling.

• Voltage should be battery positive voltage when engine

speed is higher than 4,000 r/min.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage 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 : Go to Step 2.

STEP 2. Check harness connector B-34 at engine oil
pressure switch 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 10.

STEP 3. Measure the power supply voltage at engine oil
pressure switch connector B-34.
(1) Disconnect the connector B-34 and measure at the harness

side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 1 and ground.

• Voltage should be battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is battery positive voltage (approximately 12 volts)

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

104

96

94

95

93 92 91

99 98 97

103 102 101 100

108 107 106 105

113 112 111 110 109

AK303893AB

POWER PLANT ECU
CHECK HARNESS
CONNECTOR

AK303894

1

AK303894

1

AB

CONNECTOR: B-34

B-34 (B)

HARNESS CONNECTOR:
COMPONENT SIDE

RADIATOR
UPPER HOSE

AK303894

1

AK303894

1

AB

CONNECTOR: B-34

B-34 (B)

HARNESS CONNECTOR:
COMPONENT SIDE

RADIATOR
UPPER HOSE

AK302164

1

AC

B-34 HARNESS
CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-848

STEP 4. Check harness connector B-22 at PCM for
damage.
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 10.

AK303016

104

96

94

95

93 92 91

99 98 97

103 102 101 100

108 107 106 105

113 112 111 110 109

CONNECTOR: B-22

B-22 (B)

PCM

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-849

STEP 5. Check for open or shorted circuit to ground
between engine oil pressure switch connector B-34
(terminal No. 1) and PCM connector B-22 (terminal No.
110).
Q: Is the harness wire in good condition?

YES : Replace the PCM. Then go to Step 10.
NO : Repair it. Then go to Step 10.

AK303894

1

AK303894

1

AB

CONNECTOR: B-34

B-34 (B)

HARNESS CONNECTOR:
COMPONENT SIDE

RADIATOR
UPPER HOSE

AK303016

104

96

94

95

93 92 91

99 98 97

103 102 101 100

108 107 106 105

113 112 111 110 109

CONNECTOR: B-22

B-22 (B)

PCM

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER