Mitsubishi Outlander GS45X. Manual — part 966

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-797

INSPECTION PROCEDURE 18: Transient, Mass Emission Tailpipe Test Failure.

.

COMMENT

• The test is failed when the air/fuel ratio is not con-

trolled to the ideal air/fuel ratio. This occurs due
to the feedback control by heated oxygen sensor
signals, insufficient EGR flow rate, or deteriorated
catalyst.

NOTE: If the three-way catalyst temperature is low
when checking the exhaust gas, the three-way cata-
lyst cannot sufficiently clean the emissions. Warm up
the engine sufficiently before checking the exhaust,
and check immediately.

.

TROUBLESHOOTING HINTS (The most
likely causes for this case:)

• Malfunction of air/fuel ratio control system.

• Malfunction of the EGR system.

• Deteriorated catalyst.

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 the exhaust gas with the engine at normal
operating temperature.
Q: Was the exhaust gas checked with engine warmed

sufficiently?
YES : Go to Step 2.
NO : Check it again after enough warm up.

STEP 2. Check the following items.
(1) Check the following items.

a. Check all vacuum hoses and connectors.
b. Check electrical wires and connectors for obvious prob-

lems.

Q: Are they normal?

YES : Go to Step 3.
NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

STEP 3. Check the driveability.
Q: Is the driveability normal?

YES : Go to Step 4.
NO : Refer to Symptom Chart

P.13B-55

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-798

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 any DTC set?

YES : Refer to Diagnostic Trouble Code Chart

P.13B-50

.

NO : Go to Step 5.

STEP 5. Check the ignition timing.
Refer to GROUP 11C, On-vehicle Service

− Ignition Timing

Check

P.11C-13

.

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.

STEP 6. Using scan tool MB991958, check data list.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following items in the data list. Refer to Data List

Reference Table

P.13B-836

.

a. Item 6: Engine Coolant Temperature Sensor.
b. Item 5: Intake Air Temperature Sensor.

c. Item AC: Heated Oxygen Sensor Bank 1, Sensor 1

(right front)

d. Item AE: Heated Oxygen Sensor Bank 2, Sensor 1 (left

front)

e. Item BB: Barometric Pressure Sensor

(3) 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.

AK700568AB

MB991824

MB991827

MB991910

Data link
connector

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-799

STEP 7. Using scan tool MB991958, check data list item
AD: Heated oxygen sensor bank 1, sensor 2 (right rear).
(1) Start the engine and run at idle.
(2) Set scan tool MB991958 to the data reading mode for item

AD, Heated Oxygen Sensor bank 1, sensor 2 (right rear).

a. Transaxle: 2 nd
b. Drive with wide open throttle

c. Engine: 3,500 r/min

• The output voltages should be between 0.6 and 1.0

volt.

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

YES : Go to Step 8.
NO : Refer to P0137

− Heated Oxygen Sensor Circuit Low

Voltage (bank 1, sensor 2)

P.13B-244

, DTC P0138

−

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

P.13B-250

, DTC P0139

− Heated Oxygen

Sensor Circuit Slow Response (bank 1, sensor 2)

P.13B-254

, DTC P0140

− Heated Oxygen Sensor

Circuit No Activity Detected (bank 1, sensor 2)

P.13B-259

.

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

AF, Heated Oxygen Sensor bank 2, sensor 2 (left rear).

a. Transaxle: 2 nd
b. Drive with wide open throttle

c. Engine: 3,500 r/min

• The output voltage should be between 0.6 and 1.0

volt.

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

YES : Go to Step 9.
NO : Refer to P0157

− Heated Oxygen Sensor Circuit Low

Voltage (bank 2, sensor 2)

P.13B-284

, DTC P0158

−

Heated Oxygen Sensor Circuit High Voltage (bank 2,
sensor 2)

P.13B-290

, DTC P0159

− Heated Oxygen

Sensor Circuit Slow Response (bank 2, sensor 2)

P.13B-294

, DTC P0160

− Heated Oxygen Sensor

Circuit No Activity Detected (bank 2, sensor 2)

P.13B-299

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-800

STEP 9. Check the EGR system.
Refer to GROUP 17, Emission Control

− Exhaust Gas Recircu-

lation (EGR) System

− General Information (Exhaust Gas

Recirculation System)

P.17-80

.

Q: Is the EGR system normal?

YES : Go to Step 10.
NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

STEP 10. Check the fuel pressure.
Refer to On-vehicle Service

− Fuel Pressure Test

P.13B-883

.

Q: Is the fuel pressure normal?

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

symptom is eliminated.

STEP 11. Check the spark plugs.
Refer to GROUP 16, Ignition System

− On-vehicle Service −

Spark Plug Check And Cleaning

P.16-45

.

Q: Are there any abnormalities?

YES : Replace the spark plug. Then confirm that the

malfunction symptom is eliminated.

NO : Go to Step 12.

STEP 12. Check the ignition coil.
(1) Remove the intake manifold.
(2) Refer to GROUP 16, Ignition System

− On-vehicle Service

− Ignition Coil Check

P.16-44

.

Q: Are there any abnormalities?

YES : Replace the ignition coil. Then confirm that the

malfunction symptom is eliminated.

NO : Go to Step 13.

STEP 13. Check the compression pressure.
Refer to GROUP 11C, On-vehicle Service

− Compression

Pressure Check

P.11C-18

.

Q: Is the compression pressure normal?

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

is eliminated.

STEP 14. Check the positive crankcase ventilation valve.
Refer to GROUP 17, Emission Control

− Positive Crankcase

Ventilation System

− Positive Crankcase Ventilation System

Check

P.17-74

.

Q: Is the positive crankcase ventilation valve?

YES : Go to Step 15.
NO : Repair it. Then confirm that the malfunction symptom

is eliminated.