Mitsubishi Galant (2004+). Manual - part 1335

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1033

STEP 4. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).

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) Turn the ignition switch to the "ON" position.
(3) Read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?

YES : Refer to Diagnostic Trouble Code Chart 

P.13B-33

.

NO :  Go to Step 5.

STEP 5. Check the ignition timing.

Refer to GROUP 11A, On-vehicle Service 

− Ignition Timing 

Check 

P.11A-12

.

Q: Is the ignition timing normal?

YES : Go to Step 6.
NO :  Check that the crankshaft position sensor and timing 

belt cover are in the correct position. Then confirm 
that the malfunction symptom is eliminated. 

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1034

STEP 6. Using scan tool MB991958, check data list.

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) Turn the ignition switch to the "ON" position.
(3) Check the following items in the data list. Refer to Data List 

Reference Table 

P.13B-1092

.

a. Item 21: Engine Coolant Temperature Sensor.
b. Item 13: Intake Air Temperature Sensor.

c. Item 25: Barometric Pressure Sensor.

d. Item 69: Right Bank Heated Oxygen Sensor (rear).
e. Item 59: Left Bank Heated Oxygen Sensor (rear).

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

YES : Go to Step 7.
NO :  Repair or replace it. Then confirm that the malfunction 

symptom is eliminated.

STEP 7. Using scan tool MB991958, check data list item 39: 
Heated oxygen sensor bank 1, sensor 1 (right front).

(1) Start the engine and run at idle.
(2) Set scan tool MB991958 to the data reading mode for item 

39, Heated Oxygen Sensor bank 1, sensor 1 (right 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 8.
NO :  Refer to DTC P0130 - Heated Oxygen Sensor Circuit 

(bank 1, sensor 1) 

P.13B-189

, DTC P0131 - Heated 

Oxygen Sensor Low Voltage (bank 1, sensor 1) 

P.13B-207

, DTC P0132 - Heated Oxygen Sensor 

Circuit High Voltage (bank 1, sensor 1) 

P.13B-214

, 

DTC P0133 - Heated Oxygen Sensor Circuit Slow 
Response (bank 1, sensor 1) 

P.13B-220

, DTC P0134 

- Heated Oxygen Sensor Circuit No Activity Detected 
(bank 1, sensor 1) 

P.13B-226

.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1035

STEP 8. Using scan tool MB991958, check data list item 11: 
Heated oxygen sensor bank 2, sensor 1 (left front).

(1) Start the engine and run at idle.
(2) Set scan tool MB991958 to the data reading mode for item 

11, Heated Oxygen Sensor bank 2, sensor 1 (left 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 - Heated Oxygen Sensor Circuit 

(bank 2, sensor 1) 

P.13B-300

, DTC P0151 - Heated 

Oxygen Sensor Circuit Low Voltage (bank 2, sensor 
1) 

P.13B-318

, DTC P0152 - Heated Oxygen Sensor 

Circuit High Voltage (bank 2, sensor 1) 

P.13B-325

, 

DTC P0153 - Heated Oxygen Sensor Circuit Slow 
Response (bank 2, sensor 1) 

P.13B-330

, DTC P0154 

- Heated Oxygen Sensor Circuit No Activity Detected 
(bank 2, sensor 1) 

P.13B-336

.

STEP 9. Using scan tool MB991958, check data list item 39: 
Heated oxygen sensor bank 1, sensor 1 (right front).

(1) Start the engine and run at idle.
(2) Set scan tool MB991958 to the data reading mode for item 

39, Heated Oxygen Sensor bank 1, sensor 1 (right 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.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1036

STEP 10. Check the EGR system.

Refer to GROUP 17, Emission Control System 

− General 

Description (EGR System) 

P.17-91

.

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: Heated oxygen sensor bank 1, sensor 2 (right 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, Heated Oxygen Sensor bank 1, sensor 2 (right 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 right bank heated oxygen sensor (front). 

Then confirm that the malfunction symptom is 
eliminated.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827