Mitsubishi Galant (2004+). Manual - part 1134

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-229

STEP 2. Check for exhaust leaks.
Q: Are there any abnormalities?

YES : Repair it. Then go to Step 13.
NO :  Go to Step 3.

STEP 3. Check for intake system vacuum leak.
Q: Are there any abnormalities?

YES : Repair it. Then go to Step 13.
NO :  Go to Step 4.

STEP 4. Check harness connector B-09 at the right bank 
heated oxygen sensor (front) 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 13.

1

2

3

4

AK303048

B-09 (B)

CONNECTOR: B-09

THROTTLE BODY

RIGHT BANK
HEATED OXYGEN
SENSOR (FRONT)

AB

HARNESS
CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-230

STEP 5. Check the right bank heated oxygen sensor 
(front).

(1) Disconnect the right bank heated oxygen sensor (front) 

connector B-09 and connect test harness special tool, 
MD998464, to the connector on the right bank heated 
oxygen sensor (front) side.

(2) Warm up the engine until engine coolant temperature 

reaches 80

°C (176°F) or higher.

(3) Perform a tracing for 5 minutes or more with the engine 

speed of 4,500 r/min.

(4) Connect a digital voltage meter between terminal No. 2 

(black clip) and terminal No. 4 (white clip).

(5) While repeatedly revving the engine, measure the right 

bank heated oxygen sensor (front) output voltage.

Standard value: 0.6 

− 1.0 volt

CAUTION

• Be very careful when connecting the jumper wire; 

incorrect connection can damage the oxygen sensor.

• Be careful the heater is broken when voltage of beyond 

8V is applied to the oxygen sensor heater.
NOTE: If the sufficiently high temperature (of approximate 
400

°

C or more) is not reached although the oxygen sensor 

is normal, the output voltage would be possibly low 
although the rich air-fuel ratio. Therefore, if the output volt-
age is low, use a jumper wire to connect the terminal No.1 
(red clip of special tool) and the terminal No. 3 (blue clip of 
special tool) of the oxygen sensor with a (+) terminal and (-) 
terminal of 8 V power supply respectively, then check again.

Q: Is the voltage between 0.6 and 1.0 volt?

YES : Go to Step 6.
NO :  Replace the right bank heated oxygen sensor (front). 

Then go to Step 13.

1

2

3

4

AK303048

B-09 (B)

CONNECTOR: B-09

THROTTLE BODY

RIGHT BANK
HEATED OXYGEN
SENSOR (FRONT)

AB

HARNESS
CONNECTOR:
COMPONENT SIDE

AKX01624

HEATED
OXYGEN
SENSOR
COMPONENT
SIDE
CONNECTOR

MD998464

WHITE

BLACK

AQ

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-231

STEP 6. Check harness connector B-32 at intermediate 
connector for damage.

Q: Is the harness connector in good condition?

YES : Go to Step 7.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 13.

STEP 7. Measure the right bank injector resistance at 
intermediate connector B-32.

(1) Disconnect the intermediate connector B-32.

(2) Measure the resistance between each injector side 

connector terminal.

a. Measure the resistance between terminal No. 5 and No. 

9 when measuring No. 1 cylinder.

b. Measure the resistance between terminal No. 9 and No. 

10 when measuring No. 3 cylinder.

c. Measure the resistance between terminal No. 4 and No. 

9 when measuring No. 5 cylinder.

• Resistance should be between 10.5 and 13.5 ohms [at 

20

°C (68° F)].

Q: Is the measured resistance between 10.5 and 13.5 ohms 

[at 20

°C (68°F)]?

YES : Go to Step 10.
NO :  Go to Step 8.

AK303053

3

4

5

8

9

1

2

6

7

10

CONNECTOR: B-32

HARNESS CONNECTOR:
COMPONENT SIDE

AB

B-32 (B)

AK303053

3

4

5

8

9

1

2

6

7

10

CONNECTOR: B-32

HARNESS CONNECTOR:
COMPONENT SIDE

AB

B-32 (B)

1

2 3

6

7 8

4 5

9 10

AK203093

B-32 
INTERMEDIATE
CONNECTOR

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-232

STEP 8. Check harness connector B-03, B-04, B-01 at right 
bank injector for damage.

(1) Remove the intake manifold.
(2) Check the right bank injector connector, which deviates 

from the standard value at Step 7.

Q: Is the harness connector in good condition?

YES : Go to Step 9.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 13.

STEP 9. Check the right bank injector.

(1) Check the right bank injector, which deviates from the 

standard value at Step 7.

(2) Measure the resistance between injector side connector 

terminal No. 1 and No. 2.

Standard value: 10.5 

− 13.5 ohms [at 20°C (68°F)]

Q: Is the measured resistance between 10.5 and 13.5 ohms 

[at 20

°C (68°F)]?

YES : Repair harness wire between injector intermediate 

connector and right bank injector connector because 
of harness damage. Then go to Step 13.

NO :  Replace the injector. Then go to Step 13.

AK303055

M

1

2

CONNECTOR: B-01, B-03, B-04

AB

B-01 (GR)

B-03 (GR)

B-04 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE

AK303055

M

1

2

CONNECTOR: B-01, B-03, B-04

AB

B-01 (GR)

B-03 (GR)

B-04 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE

AK000559

2

1

INJECTOR SIDE
CONNECTOR

AB