Mitsubishi Galant 9G. Manual — part 897

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1030

STEP 8. Using scan tool MB991958, check data list item 11:
Cylinder 2, 3 Heated oxygen sensor (front).
(1) Start the engine and run at idle.
(2) Set scan tool MB991958 to the data reading mode for item

11, Cylinder 2, 3 Heated Oxygen Sensor (front).

• Output voltage should be 0.6 − 1.0 volt at sudden

engine revving.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : Go to Step 9.
NO : Refer to DTC P0150

− Cylinder 2, 3 Heated Oxygen

Sensor Circuit (sensor 1)

P.13A-299

, DTC P0151

−

Cylinder 2, 3 Heated Oxygen Sensor Circuit Low
Voltage (sensor 1)

P.13A-317

, DTC P0152

− Cylinder

2, 3 Heated Oxygen Sensor Circuit High Voltage
(sensor 1)

P.13A-324

, DTC P0153

− Cylinder 2, 3

Heated Oxygen Sensor Circuit Slow Response
(sensor 1)

P.13A-329

, DTC P0154

− Cylinder 2, 3

Heated Oxygen Sensor Circuit No Activity Detected
(sensor 1)

P.13A-335

.

STEP 9. Using scan tool MB991958, check data list item 39:
Cylinder 1, 4 Heated oxygen sensor (front).
(1) Start the engine and run at idle.
(2) Set scan tool MB991958 to the data reading mode for item

39, Cylinder 1, 4 Heated Oxygen Sensor (front).

• Voltage should fluctuate between 0 − 0.4 volt and 0.6 −

1.0 volt while after the engine has been warmed.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : Go to Step 10.
NO : Go to Step 12.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1031

STEP 10. Check the EGR system.
Refer to GROUP 17, Emission Control System

− General

Description (EGR System)

P.17-89

.

Q: Is the EGR system normal?

YES : Go to Step 11.
NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

STEP 11. Using scan tool MB991958, check data list item
69: Cylinder 1, 4 Heated oxygen sensor (rear).

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Start the engine and run at idle.
(3) Set scan tool MB991958 to the data reading mode for item

69, Cylinder 1, 4 Heated Oxygen Sensor (rear).

• Average voltage should be 0.6 volt or less, when idling.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : Go to Step 16.
NO : Replace the cylinder 1, 4 heated oxygen sensor

(front). Then confirm that the malfunction symptom is
eliminated.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1032

STEP 12. Using scan tool MB991958, check data list item
11: Cylinder 2, 3 Heated oxygen sensor (front).
(1) Start the engine and run at idle.
(2) Set scan tool MB991958 to the data reading mode for item

11, Cylinder 2, 3 Heated Oxygen Sensor (front).

• Warm up the engine. When the engine is decelerated

suddenly from 4,000 r/min, the output voltage should
increase from 0.2 volt or less to 0.6

− 1.0 volt in a few

seconds.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : Go to Step 13.
NO : Go to Step 15.

STEP 13. Check the EGR system.
Refer to GROUP 17, Emission Control System

− General

Description (EGR System)

P.17-89

.

Q: Is the EGR system normal?

YES : Go to Step 14.
NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1033

STEP 14. Using scan tool MB991958, check data list item
59: Cylinder 2, 3 Heated oxygen sensor (rear).

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Start the engine and run at idle.
(3) Set scan tool MB991958 to the data reading mode for item

59, Cylinder 2, 3 Heated Oxygen Sensor (rear).

• Average voltage should be 0.6 volt or less, when idling.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : Go to Step 16.
NO : Replace the cylinder 2, 3 heated oxygen sensor

(front). Then confirm that the malfunction symptom is
eliminated.

STEP 15. Check the fuel pressure.
Refer to On-vehicle Service

− Fuel Pressure Test

P.13A-1124

.

Q: Is the fuel pressure normal?

YES : Go to Step 16.
NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

STEP 16. Check the following items.
(1) Check the following items, and repair or replace the

defective items.

a. Check the injectors for fuel leakage.
b. Check the ignition coil and spark plugs.

c. Check compression pressure.

d. Check the positive crankcase ventilation system.
e. Check the evaporative emission system.

(2) Then check the malfunction symptom.
Q: Is the malfunction symptom eliminated?

YES : The check is completed.
NO : Replace the catalytic converter. Then confirm that the

malfunction symptom is eliminated.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827