Mitsubishi Outlander GS45X. Manual - part 713

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-675

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

STEP 1. Check harness connector C-142 at linear air-fuel 
ratio sensor and harness connector B-10 at ECM 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 5.

STEP 2. Check for open circuit between linear air-fuel ratio 
sensor connector C-142 (terminal No. 1) and ECM 
connector B-10 (terminal No. 56).
NOTE: Check harness after checking intermediate connector 
A-12. If intermediate connector is damaged, repair or replace it. 
Refer to GROUP 00E, Harness Connector Inspection 

P.00E-2

. 

Then go to Step 5.
Q: Is the harness wire in good condition?

YES : Go to Step 3.
NO :  Repair it. Then go to Step 5.

STEP 3. Test the OBD-II drive cycle.

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 and delete the 

DTC.

(3) Carry out the test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− OBD-II Drive Cycle − Pattern 22 

P.13A-11

.

(4) Check the diagnostic trouble code (DTC).
Q: Is DTC P2237 set?

YES : Then go to Step 4.
NO :  It can be assumed that this malfunction is intermittent. 

Refer to GROUP 00, How to Use Troubleshooting/ 
Inspection Service Points 

− How to Cope with 

Intermittent Malfunctions 

P.00-15

.

AK700568AB

MB991824

MB991827

MB991910

Data link
connector

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-676

STEP 4. Replace the linear air-fuel ratio sensor.
(1) Replace the linear air-fuel ratio sensor.
(2) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− OBD-II Drive Cycle − Pattern 22 

P.13A-11

.

(3) Check the diagnostic trouble code (DTC).
Q: Is DTC P2237 set?

YES : Replace the ECM. When the ECM is replaced, 

register the ID code. Refer to GROUP 42B, Diagnosis 
− ID Code Registration Judgment Table <Vehicles 

with KOS> 

P.42B-15

 or GROUP 42C, Diagnosis 

− ID 

Codes Registration Judgment Table <Vehicles with 
WCM> 

P.42C-10

. Then go to Step 5.

NO :  The inspection is complete.

STEP 5. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− OBD-II Drive Cycle − Pattern 22 

P.13A-11

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P2237 set?

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

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-677

DTC P2243: Linear Air-Fuel Ratio Sensor Reference Voltage Circuit/Open

1

2

3 4 5 6 7 8 9 10 11 12 13 14 15 16

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

P

3

2

1

6

5

4

AKA00449

1

12 13 14 15 16 1718 19 20 2122 2324

2 3 4 5

6 7 8 9 10 11

LINEAR AIR-FUEL RATIO SENSOR CIRCUIT

LINEAR 
AIR-FUEL 
RATIO 
SENSOR

FROM 
MFI RELAY

WHITE

BLA

CK

RED

WHITE

BLA

CK

RED

C-142

ENGINE
CONTROL
MODULE

38

39

56

4

5

1

14

20

21

2

6

3

B-10

A-12

AC

TO ECM TO ECM

AKA00842 AB

Connector: A-12

A-12

AK704090AB

Connector: B-10

B-10 (GR)

AK704089AD

Linear air-fuel
ratio sensor

SRS-ECU

Connector: C-142

C-142 (B)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-678

.

CIRCUIT OPERATION

The linear air-fuel ratio sensor and the ECM are con-
nected by the following three lines to detect the 
air-fuel ratio.

• The line between the linear air-fuel ratio sensor 

(terminal No. 1) and the ECM (terminal No. 56) 
detects the air-fuel ratio.

• The auxiliary line between the linear air-fuel ratio 

sensor (terminal No. 4) and the ECM (terminal 
No. 38) detects the air-fuel ratio.

• The line between the linear air-fuel ratio sensor 

(terminal No. 5) and the ECM (terminal No. 39) is 
connected to ground.

.

TECHNICAL DESCRIPTION

• The ECM effects air/fuel ratio feedback control in 

accordance with the signals from the linear 
air-fuel ratio sensor.

• If the linear air-fuel ratio sensor has deteriorated, 

corrections will be made by the heated oxygen 
sensor (rear).

.

DESCRIPTIONS OF MONITOR METHODS

• The linear air-fuel ratio sensor heater or the 

exhaust gas heats the linear air-fuel ratio sensor 
to sufficiently activate the linear air-fuel ratio sen-
sor, resulting in the small resistance. However, 
the DTC is stored as an open circuit if the large 
resistance continues.

.

MONITOR EXECUTION

Continuous

.

MONITOR EXECUTION CONDITIONS 
(Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• Linear air-fuel ratio sensor heater monitor

• Misfire monitor

• Fuel system monitor

Sensor (The sensor below is determined to be 

normal)

• Mass airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

• Barometric pressure sensor

• Throttle position sensor

• Accelerator pedal position sensor

.