Mitsubishi Galant (2004+). Manual - part 882

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-345

DIAGNOSIS

Required Special Tools:

• MB991316: Test Harness

• MB991923: Check Harness

STEP 1. Check harness connector B-36 at the cylinder 2, 3 
heated oxygen sensor (front) for damage.

Q: Is the harness connector in good condition?

YES : Go to Step 2.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 12.

AK303830

1

2

3

4

AB

CONNECTOR: B-36 

B-36 (GR)

CYLINDER 2, 3
HEATED OXYGEN
SENSOR (FRONT)

HARNESS
CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-346

STEP 2. Check the cylinder 2, 3 heated oxygen sensor 
(front).

(1) Disconnect cylinder 2, 3 heated oxygen sensor (front) 

connector B-36 and connect test harness special tool, 
MB991316, to the connector on the cylinder 2, 3 heated 
oxygen (front) sensor side.

(2) Measure the resistance between heated oxygen sensor 

connector terminal No. 1 (red clip) and terminal No. 3 (blue 
clip).

Standard value: 4.5 

− 8.0 ohms [at 20°C (68°F)]

Q: Is the measured resistance between 4.5 and 8.0 ohms 

[at 20

°C (68°F)]?

YES : Go to Step 3.
NO :  Replace the cylinder 2, 3 heated oxygen sensor 

(front). Then go to Step 12.

AK303830

1

2

3

4

AB

CONNECTOR: B-36 

B-36 (GR)

CYLINDER 2, 3
HEATED OXYGEN
SENSOR (FRONT)

HARNESS
CONNECTOR:
COMPONENT SIDE

AKX01624 AB

MB991316

HEATED
OXYGEN
SENSOR
EQUIPMENT
SIDE
CONNECTOR

BLUE

RED

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-347

STEP 3. Measure the power supply voltage at cylinder 2, 3 
heated oxygen sensor (front) harness side connector B-36.

(1) Disconnect the connector B-36 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 5.
NO :  Go to Step 4.

STEP 4. Check harness connector B-17X at the MFI relay 
for damage.

Q: Is the harness connector in good condition?

YES : Repair harness wire between MFI relay connector 

B-17X (terminal No. 4) and cylinder 2, 3 heated 
oxygen sensor (front) connector B-36 (terminal No. 1) 
because of open circuit or short circuit to ground. 
Then go to Step 12.

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

Connector Inspection 

P.00E-2

. Then go to Step 12. 

AK303830

1

2

3

4

AB

CONNECTOR: B-36 

B-36 (GR)

CYLINDER 2, 3
HEATED OXYGEN
SENSOR (FRONT)

HARNESS
CONNECTOR:
COMPONENT SIDE

AKX01496

B-36 HARNESS 
CONNECTOR: 
COMPONENT SIDE

1

2

3

4

AY

AK303806

2

1

3

4

AB

CONNECTOR: B-17X

B-17X

RELAY BOX
TRIANGLE 
MARK

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-348

STEP 5. Measure the power supply voltage at PCM 
connector B-23 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) Turn the ignition switch to the "ON" position.

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AK303058

HARNESS CONNECTOR: 
COMPONENT SIDE

CONNECTOR: B-23

B-23

PCM

AB

AIR CLEANER

AK202954

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146 145 144 143 142 141

153 152 151 150 149 148 147

AB

POWER PLANT ECU 
CHECK HARNESS CONNECTOR

MB991923

PCM