Mitsubishi Montero (2004+). Manual — part 258

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-519

• MB991911: Main Harness B

STEP 1. Check the exhaust leaks.
Q: Are there any abnormalities?

YES : Go to Step 2.
NO : Repair it. Then go to Step 7.

STEP 2. Using scan tool MB991958, check data list item 59:
Heated Oxygen Sensor Bank 2, Sensor 2 (left 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, Heated Oxygen Sensor Bank 2, Sensor 2 (left rear).

• Warming up the engine. When the engine is revved, the

output voltage should repeat 0 volt and 0.6 to 1.0 volt
alternately.

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

YES : Go to Step 3.
NO : Refer to DTC P0156

− Heated Oxygen Sensor Circuit

(Bank 2, Sensor 2)

P.13A-322

, DTC P0157

− Heated

Oxygen Sensor Circuit Low Voltage (Bank 2, Sensor
2)

P.13A-338

, DTC P0158

− Heated Oxygen Sensor

Circuit High Voltage (Bank 2, Sensor 2)

P.13A-345

,

DTC P0159

− Heated Oxygen Sensor Circuit Slow

Response (Bank 2, Sensor 2)

P.13A-350

.

STEP 3. 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).

• Warming up the engine. When the engine is revved, the

output voltage should be 0.6 to 1.0 volt.

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

YES : Go to Step 4.
NO : Refer to DTC P0150

− Heated Oxygen Sensor Circuit

(Bank 2, Sensor 1)

P.13A-268

, DTC P0151

− Heated

Oxygen Sensor Circuit Low Voltage (Bank 2, Sensor
1)

P.13A-284

, DTC P0152

− Heated Oxygen Sensor

Circuit High Voltage (Bank 2, Sensor 1)

P.13A-291

,

DTC P0153

− Heated Oxygen Sensor Circuit Slow

Response (Bank 2, Sensor 1)

P.13A-296

, DTC P0154

− Heated Oxygen Sensor Circuit No Activity Detected

(Bank 2, Sensor 1)

P.13A-302

.

AK302970

AB

MB991911

MB991824

MB991827

AK302970

AB

MB991911

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-520

STEP 4. 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).

(3) Keep the engine speed at 2,000 r/min.

• 0 − 0.4 and 0.6 − 1.0 volt should alternate 15 times or

more within 10 seconds.

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

YES : Go to Step 5.
NO : Replace the left bank heated oxygen sensor (front).

Then go to Step 7.

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 − Procedure 3 −

Catalytic Converter Monitor

P.13A-4

.

(2) Read the diagnostic trouble code.
Q: Is DTC P0431 set?

YES : Replace the left bank side catalytic converter. Then

go to Step 6.

NO : The inspection is complete.

STEP 6. 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 − Procedure 3 −

Catalytic Converter Monitor

P.13A-4

.

(2) Read the diagnostic trouble code.
Q: Is DTC P0431 set?

YES : Replace the PCM. Then go to Step 7.
NO : The inspection is complete.

STEP 7. 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 − Procedure 3 −

Catalytic Converter Monitor

P.13A-4

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0431 set?

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

AK302970

AB

MB991911

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-521

DTC P0441: Evaporative Emission Control System Incorrect Purge Flow

.

TECHNICAL DESCRIPTION

• PCM detects stuck open condition of evaporative

emission purge solenoid valve and stuck closed
condition of evaporative emission ventilation
solenoid valve by pressure change in fuel tank.

• Stuck open evaporative emission purge solenoid

valve is judged through monitoring leak of evapo-
rative emission system.

• Stuck closed evaporative emission ventilation

solenoid valve is judged after 20 seconds from
end of monitoring leak of evaporative emission
system, or of usual operation of evaporative
emission purge solenoid from ON to OFF.

.

DESCRIPTIONS OF MONITOR METHODS
Fuel tank pressure decreases largely during

purge-cut.

.

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)

• Fuel tank pressure sensor monitor

Sensor (The sensor below is determined to be

normal)

• Not applicable

.

AK200968

EVAPORATIVE
EMISSION PURGE
SOLENOID

AB

B-06(B)

CONNECTOR: B-06

AK201059

AK201059

G-27(B)

AD

CONNECTOR: G-27

EVAPORATIVE EMISSION
VENTILATION SOLENOID

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-522

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• ON duty cycle of the evaporative emission purge

solenoid is 0 percent.

• Engine is running.

• 20 seconds have elapsed since the duty cycle of

the evaporative emission purge solenoid has
turned to 0 percent.

Judgment Criteria

• The pressure in the fuel tank is −1961 Pa (−0.58

in.Hg) or less for 0.1 second.

.

OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function

− OBD-II Drive Cycle −

Procedure 1

− Evaporative Emission System

Leak Monitor

P.13A-4

.

.

TROUBLESHOOTING HINTS (The most likely
causes for this code to be set are:)

• Evaporative emission purge solenoid failed.

• Evaporative emission ventilation solenoid failed.

• Fuel tank differential pressure sensor circuit

related part failed.

START

END

NO

NO

NO

NO

YES

YES

YES

NO

MALFUNCTION

GOOD

CONTINUOUS

FAILURE FOR 100msecs

MONITORING CONDITIONS FOR

MALFUNCTION DETECTION

AK302953

FUEL-TANK PRESSURE

< -1961Pa (-0.58in.Hg)

MONITORING CONDITIONS FOR

PASS JUDGEMENT?

REVERTING PRESSURE

DETECTED DURING

EVAP MONITOR?

YES

YES