Mitsubishi Lancer Evolution X. Manual - part 301

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-269

Judgement Criterion

• Long-term fuel trim has continued to be +12.5 

percent or higher for 5 seconds.

or

• Short-term fuel trim has continued to be +12.1 

percent or higher for 5 seconds.

Check Conditions

• Engine coolant temperature is higher than 100° C 

(212° F) when the engine is started.

• Intake air temperature is higher than 60° C 

(140° F) when the engine is started.

• Under the closed loop air/fuel ratio control.
• Engine coolant temperature is higher than 76° C 

(169° F).

• Mass airflow sensor output is 13 g/sec or more.

Judgement Criteria

• Long-term fuel trim has continued to be +12.5 

percent or higher for 5 seconds.

or

• Short-term fuel trim has continued to be +17.2 

percent or higher for 5 seconds.

Check Conditions

• Engine coolant temperature is higher than 100° C 

(212° F) when the engine is started.

• Intake air temperature is higher than 60° C 

(140° F) when the engine is started.

• Under the closed loop air/fuel ratio control.
• Engine coolant temperature is higher than 76° C 

(169° F).

• Mass airflow sensor output is less than 13 g/sec.

Judgement Criterion

• Long-term fuel trim has continued to be +12.5 

percent or higher for 5 seconds.

or

• Short-term fuel trim has continued to be +22.3 

percent or higher for 5 seconds.

Check Conditions

• Engine coolant temperature is higher than 76° C 

(169° F).

• Under the closed loop air/fuel ratio control.

Judgement Criterion

• Long-term fuel trim has continued to be +12.5 

percent for 2 seconds.

or

• Short-term fuel trim has continued to be +25.0 

percent for 2 seconds.

.

FAIL-SAFE AND BACKUP FUNCTION

• None

.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function − OBD-II Drive Cycle − 

Pattern 21 

P.13A-9

.

.

TROUBLESHOOTING HINTS (The most likely 

causes for this code to be set are:)

• Mass airflow sensor failed.
• Injector failed.
• Incorrect fuel pressure.
• Air drawn in from gaps in gasket, seals, etc.
• Engine coolant temperature sensor failed.
• Intake air temperature sensor failed.
• Barometric pressure sensor failed.
• Manifold absolute pressure sensor failed.
• Exhaust leak.
• Use of incorrect or contaminated fuel.
• Harness damage in injector circuit or connector 

damage.

• ECM failed. 

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 for exhaust leak.
Q: Are there any abnormalities?

YES : Repair it. Then go to Step 14.
NO :  Go to Step 2.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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STEP 2. Check for intake system vacuum leak.
Q: Are there any abnormalities?

YES : Repair it. Then go to Step 14.
NO :  Go to Step 3.

STEP 3. Using scan tool MB991958, check data list item 10: 
Mass Airflow Sensor.

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 

10, Mass Airflow Sensor.

(4) Warm up the engine to normal operating temperature: 80° C 

to 95° C (176° F to 203° F).

• When idling, between 1,300 and 1,650 millivolts.
• When 2,500 r/min, between 1,620 and 2,100 millivolts.

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

YES : Go to Step 4.
NO :  Refer to DTC P0101 − Mass Airflow Circuit 

Range/Performance Problem 

P.13A-126

, DTC P0102 

− Mass Airflow Circuit Low Input 

P.13A-132

, DTC 

P0103 − Mass Airflow Circuit High Input 

P.13A-139

.

STEP 4. Using scan tool MB991958, check data list item 5: 
Intake Air Temperature Sensor.
(1) Turn the ignition switch to the "ON" position.
(2) Set scan tool MB991958 to the data reading mode for item 

5, Intake Air Temperature Sensor.

• The intake air temperature and temperature shown with 

the scan tool should approximately match.

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

YES : Go to Step 5.
NO :  Refer to DTC P0111 − Intake Air Temperature Circuit 

Range/Performance Problem (sensor 1) 

P.13A-166

, 

DTC P0112 − Intake Air Temperature Circuit Low Input 

(sensor 1) 

P.13A-172

, DTC P0113 − Intake Air 

Temperature Circuit High Input (sensor 1) 

P.13A-176

.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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STEP 5. Using scan tool MB991958, check data list item 6: 
Engine Coolant Temperature Sensor.
(1) Turn the ignition switch to the "ON" position.
(2) Set scan tool MB991958 to the data reading mode for item 

6, Engine Coolant Temperature Sensor.

• The engine coolant temperature and temperature 

shown with the scan tool should approximately match.

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

YES : Go to Step 6.
NO :  Refer to DTC P0116 − Engine Coolant Temperature 

Circuit Range/Performance Problem

P.13A-182

, DTC 

P0117 − Engine Coolant Temperature Circuit Low 

Input 

P.13A-188

, DTC P0118 − Engine Coolant 

Temperature Circuit High Input 

P.13A-193

.

STEP 6. Using scan tool MB991958, check data list item 8: 
Manifold Absolute Pressure Sensor.
(1) Turn the ignition switch the "ON" position.
(2) Set scan tool MB991958 to the data reading mode for item 

8, Manifold Absolute Pressure Sensor.

• When altitude is 0 m (0 foot), 101 kPa (29.8 in.Hg).
• When altitude is 600 m (1,969 feet), 95 kPa (28.1 in.Hg).
• When altitude is 1,200 m (3,937 feet), 88 kPa (26.0 

in.Hg).

• When altitude is 1,800 m (5,906 feet), 81 kPa (23.9 

in.Hg).

(3) Start the engine.

• When the engine is idling, 31 − 45 kPa (9.1 − 13.3 in.Hg).
• When the engine is suddenly revved, manifold absolute 

pressure varies.

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

YES : Go to Step 7.
NO :  Refer to DTC P0106 − Manifold Absolute Pressure 

Circuit Range/Performance Problem 

P.13A-144

, DTC 

P0107 − Manifold Absolute Pressure Circuit Low Input 

P.13A-153

, DTC P0108 − Manifold Absolute Pressure 

Circuit High Input 

P.13A-161

.

STEP 7. Check harness connector B-101, B-102, B-103 and 
B-104 at injector for damage.
Q:  Is the harness connector in good condition?

YES : Go to Step 8.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 14.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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STEP 8. Check the injector.
(1) Disconnect the injector connector B-101, B-102, B-103 and 

B-104.

(2) Measure the resistance between each injector side 

connector terminal No. 1 and No. 2.

Standard value: 10.5 − 13.5 Ω [at 20° C (68° F)]

Q: Is the measured resistance between 10.5 and 13.5 Ω [at 

20° C (68° F)]?
YES : Go to Step 9.
NO :  Replace the injector. Then go to Step 14.

STEP 9. Check harness connector B-09 at ECM for 
damage.
Q: Is the harness connector in good condition?

YES : Go to Step10. 
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 14.

STEP 10. Check for harness damage between injector 
connector and ECM connector.

a. Check the harness wire between injector connector B-101 

(terminal No. 2) and ECM connector B-09 (terminal No. 2) 
at No. 1 cylinder injector.

b. Check the harness wire between injector connector B-102 

(terminal No. 2) and ECM connector B-09 (terminal No.3) at 
No. 2 cylinder injector.

c. Check the harness wire between injector connector B-103 

(terminal No. 2) and ECM connector B-09 (terminal No. 18) 
at No. 3 cylinder injector.

d. Check the harness wire between injector connector B-104 

(terminal No. 2) and ECM connector B-09 (terminal No. 19) 
at No. 4 cylinder injector.

Q: Is the harness wire in good condition?

YES : Go to Step 11.
NO :  Repair it. Then go to Step 14.

STEP 11. Check the fuel pressure.
Refer to On-vehicle Service − Fuel Pressure Test 

P.13A-865

. 

Q: Is the fuel pressure normal?

YES : Go to Step 12.
NO :  Repair it. Then go to Step 14.

STEP 12. Check for entry of foreign matter (water, 
kerosene, etc.) into fuel.
Q: Are there any abnormalities?

YES : Replace the fuel. Then go to Step 14.
NO :  Go to Step 13.

AK604038

1 2

AB

Injector side
connector