Mitsubishi Galant. Manual — part 259

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-261

STEP 3 Check the EGR solenoid.
(1) Disconnect the EGR solenoid connector B-03.
(2) Measure the resistance between EGR solenoid side

connector terminal 1 and 2.

Standard value: 29

−−−−

35

Ω

Ω

Ω

Ω

[at 20

°°°°

C (68

°°°°

F)]

Q: Is the resistance at the standard value?

YES : Go to Step 4.
NO : Replace the EGR solenoid. Then go to Step 12.

STEP 4. Check the power supply voltage at EGR solenoid
harness side connector B-03.
(1) Disconnect the connector B-03 and measure at the harness

side.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 1 and ground.

•

Voltage should be battery positive voltage

(4) Turn the ignition switch to the "LOCK"(OFF) position.

Q: Is the voltage normal?

YES : Go to Step 6.
NO : Go to Step 5.

STEP 5. Check connector A-21X at MFI relay for damage.
Q: Is the connector in good condition?

YES : Repair harness wire between MFI relay connector A-

21X terminal 1 and EGR solenoid connector B-03
terminal 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.

ACX02514

CONNECTOR:B-03

EGR
SOLENOID
VALVE

AH

AKX00352

AK000254

B-03 HARNESS
SIDE CONNECTOR

1

2

AD

AK000555AB

CONNECTOR : A-21X

MFI RELAY

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-262

STEP 6. Check the power supply voltage at PCM connector
C-39 by backprobing
(1) Do not disconnect the connector C-39.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 6 and ground by

backprobing.

•

Voltage should be battery positive voltage.

(4) Turn the ignition switch to the "LOCK"(OFF) position.

Q: Is the voltage normal?

YES : Go to Step 9.
NO : Go to Step 7.

STEP 7. Check connector C-39 at PCM for damage.
Q: Is the connector in good condition?

YES : Go to Step 8.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection(

P.00E-2

). Then go to Step 12.

STEP 8. Check for open circuit and short circuit to ground
between EGR solenoid connector B-03 terminal 2 and PCM
connector C-39 terminal 6.
Q: Is the harness wire in good condition?

YES : Replace the PCM. Then go to Step 12.
NO : Repair it. Then go to Step 12.

AK000299

C-39 CONNECTOR
HARNESS SIDE VIEW

1
9

24

2

10 11

25

3

12

26

4

13

27

5

19

32

6

20 21
33

7

22
34

8

23
35

14

28

15 16

29

17

30

18

31

AC

AK000280

CONNECTOR : C-39

PCM

AW

ACX02514

CONNECTOR:B-03

EGR
SOLENOID
VALVE

AH

AK000280

CONNECTOR : C-39

PCM

AW

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-263

STEP 9. Check connector C-39 at PCM for damage.
Q: Is the connector in good condition?

YES : Go to Step 10.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection(

P.00E-2

). Then go to Step 12.

STEP 10. Check for harness damage between MFI relay
connector A-21X terminal 1 and EGR solenoid connector
B-03 terminal 1.
Q: Is the harness wire in good condition?

YES : Go to Step 11.
NO : Repair it. Then go to Step 12.

AK000280

CONNECTOR : C-39

PCM

AW

AK000555AB

CONNECTOR : A-21X

MFI RELAY

ACX02514

CONNECTOR:B-03

EGR
SOLENOID
VALVE

AH

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-264

STEP 11. Check for harness damage between EGR
solenoid connector B-03 terminal 2 and PCM connector C-
39 terminal 6.
Q: Is the harness wire in good condition?

YES : Replace the PCM. Then go to Step 12.
NO : Repair it. Then go to Step 12.

STEP 12. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to,

Procedure 6

−

Other Monitor(

P.13B-4

).

(2) Check the diagnostic trouble code (DTC).

Q: Is the DTC P0403 is output?

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

DTC P0421: Warm Up Catalyst Efficiency Below Threshold (bank 1)

TECHNICAL DESCRIPTION

•

The signal from the rear heated oxygen sensor
differs from the front heated oxygen sensor.That
is because the catalytic converter purifies
exhaust gas. When the catalytic converter has
deteriorated, the signal from the front heated
oxygen sensor becomes similar to the rear
heated oxygen sensor.

•

The PCM compares the output of the front and
rear heated oxygen sensor signals.

DTC SET CONDITIONS

Check Conditions

•

Engine speed is lower than 3,000 r/min.

•

Volume air flow sensor output frequency is
between 69 and 169 Hz.

•

Intake air temperature is higher than -10

°

C (14

°

F).

•

Barometric pressure is higher than 76 kPa (11
psi).

•

The throttle valve is open.

•

Under the closed loop air / fuel ratio control.

•

Vehicle speed is 1.5 km/h (0.93 mph) or more.

•

Monitoring time: 84 seconds.

Judgment Criteria

•

The right bank heated oxygen sensor (rear)
signal and right bank heated oxygen sensor
(front) signal are similar.

ACX02514

CONNECTOR:B-03

EGR
SOLENOID
VALVE

AH

AK000280

CONNECTOR : C-39

PCM

AW