Mitsubishi Galant (2004+). Manual - part 1287

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-841

STEP 7. Measure the power supply voltage at PCM harness 
side connector D-23.

(1) Disconnect the connector B-23 and measure at the harness 

side.

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

(3) Measure the voltage between terminal No. 122 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 10.
NO :  Go to Step 8.

127 126 125 124 123 122 121

133 132 131 130 129 128

140 139 138 137 136 135 134

146 145 144 143 142 141

153 152 151 150 149 148 147

AK303058

HARNESS CONNECTOR: 
COMPONENT SIDE

CONNECTOR: B-23

B-23

PCM

AB

AIR CLEANER

127 126 125 124 123 122 121

133 132 131 130 129 128

140 139 138 137 136 135 134

146 145 144 143 142 141

153 152 151 150 149 148 147

AK303183

AB

B-23 HARNESS 
CONNECTOR: 
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-842

STEP 8. Check for open circuit and short circuit to ground 
between throttle actuator control motor relay connector 
B-14X (terminal No. 4) and PCM connector B-23 (terminal 
No. 122).

Q: Is the harness wire in good condition?

YES : Go to Step 9.
NO :  Repair it. Then go to Step 14.

1

2

3

4

AK303175

CONNECTOR: B-14X

FRONT OF VEHICLE

B-14X

AB

HARNESS
CONNECTOR:
COMPONENT SIDE

RELAY BOX

127 126 125 124 123 122 121

133 132 131 130 129 128

140 139 138 137 136 135 134

146 145 144 143 142 141

153 152 151 150 149 148 147

AK303058

HARNESS CONNECTOR: 
COMPONENT SIDE

CONNECTOR: B-23

B-23

PCM

AB

AIR CLEANER

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-843

STEP 9. Check for harness damage between MFI relay 
connector B-17X (terminal No. 4) and throttle actuator 
control motor relay connector B-14X (terminal No. 2).

Q: Is the harness wire in good condition?

YES : Repair harness wire between throttle actuator control 

motor relay connector B-14X (terminal No. 3) and 
PCM connector B-23 (terminal No. 123) because of 
harness damage. Then go to Step 14.

NO :  Repair it. Then go to Step 14.

1

2

3

4

AK303017

CONNECTOR: B-17X

FRONT OF VEHICLE

B-17X

AB

HARNESS
CONNECTOR:
COMPONENT SIDE

RELAY BOX

1

2

3

4

AK303175

CONNECTOR: B-14X

FRONT OF VEHICLE

B-14X

AB

HARNESS
CONNECTOR:
COMPONENT SIDE

RELAY BOX

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-844

STEP 10. Check connector B-23 at PCM for damage.

Q:  Is the connector in good condition?

YES : Go to Step 11.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 14.

STEP 11. Check for harness damage between battery and 
throttle actuator control motor relay connector B-14X 
(terminal No. 1).

Q: Is the harness wire in good condition?

YES : Go to Step 12.
NO :  Repair it. Then go to Step 14.

127 126 125 124 123 122 121

133 132 131 130 129 128

140 139 138 137 136 135 134

146 145 144 143 142 141

153 152 151 150 149 148 147

AK303058

HARNESS CONNECTOR: 
COMPONENT SIDE

CONNECTOR: B-23

B-23

PCM

AB

AIR CLEANER

1

2

3

4

AK303175

CONNECTOR: B-14X

FRONT OF VEHICLE

B-14X

AB

HARNESS
CONNECTOR:
COMPONENT SIDE

RELAY BOX