Mitsubishi Lancer Evolution X. Manual - part 416

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-729

STEP 6. Measure the voltage at ECM connector B-09 by
using check harness special tool MB992110.
(1) Disconnect all ECM connectors. Connect the check

harness special tool MB992110 between the separated
connectors.

(2) Start the engine and run at idle.

NOTE: Vehicles for Canada, the headlight, taillight, etc.
remain lit even when the lighting switch is in "OFF" position
but this is no problem for checks.

(3) Measure the voltage between terminal No. 60 and ground.

a. Engine: warming up, idling
b. Radiator fan: stopped

c. Headlight: OFF to ON

d. Stop light: OFF to ON
e. Rear defogger switch: OFF to ON

• Voltage increases

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the harness measured voltage within the specified

range?
YES : Go to Step 7.
NO : Replace the generator. Then confirm that the

malfunction symptom is eliminated.

STEP 7. Check the spark plugs.
Refer to GROUP 16, Ignition System − On-vehicle Service −

Spark Plug Check And Cleaning

P.16-39

Q: Are there any abnormalities?

YES : Replace the spark plug. Then confirm that the

malfunction symptom is eliminated.

NO : Go to Step 8.

STEP 8. Check the ignition coil.
Refer to GROUP 16, Ignition System − On-vehicle Service −

Ignition Coil Check And Cleaning

P.16-37

Q: Are there any abnormalities?

YES : Replace the ignition coil. Then confirm that the

malfunction symptom is eliminated.

NO : Go to Step 9.

AK604040

ECM

Body side harness

MB992110

AK604041

16 15 14 13 12 11 10 9 8 7 6 5 4 3

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

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

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

Power plant ECU
check harness connector

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-730

STEP 9. Check the compression pressure.
Refer to GROUP 11A, On-vehicle Service − Compression Pres-

sure Check

P.11A-15

Q: Is the compression pressure normal?

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

is eliminated.

STEP 10. Check the positive crankcase ventilation system.
Refer to GROUP 17, Emission Control System − Positive

Crankcase Ventilation System − Positive Crankcase Ventilation

System Check

P.17-72

Q: Is the positive crankcase ventilation system?

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

is eliminated.

STEP 11. Check the purge control system.
Refer to GROUP 17, Emission Control System − Evaporative

Emission Control System − Purge Control System Check

(Purge Flow Check)

P.17-75

Q: Is the purge control system normal?

YES : Check the following items, and repair or replace the

defective items.

1. Vacuum leak.
2. Check if fuel is contaminated.
3. Check if the injectors are clogged.

Then confirm that the malfunction symptom is

eliminated.

NO : Repair it. Then confirm that the malfunction symptom

is eliminated.

Inspection procedure 8: Idle speed is high (improper idle speed)

COMMENT

• In such cases as the above, the cause is proba-

bly that the intake air volume during idle is too
great.

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

• Malfunction of the engine coolant temperature

sensor signal.

• Malfunction of the accelerator pedal position sen-

sor (main) signal.

• Malfunction of the accelerator pedal position sen-

sor (sub) signal.

• Malfunction of the A/C switch signal.
• Malfunction of the power steering pressure switch

signal.

• Malfunction of the evaporative emission control

system.

• Malfunction of the ECM.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-731

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. 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.13A-48

NO : Go to Step 2.

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

Reference Table

P.13A-818

a. Item 6: Engine Coolant Temperature Sensor.
b. Item 11: Accelerator pedal position sensor (main)

c. Item 12: Accelerator pedal position sensor (sub)

d. Item 76: A/C switch
e. Item 83: Power steering pressure switch

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

YES : Refer to GROUP 17, Emission Control System −

Evaporative Emission Control System − Evaporative

Emission Purge Solenoid Check

P.17-76

NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

AC608435

Data link connector

MB991827

MB991824

MB991910

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-732

Inspection procedure 9: Idle speed is low (improper idle speed)

COMMENT

• In cases such as the above, the cause is proba-

bly that the intake air volume during idle is too
small.

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

• Malfunction of the engine coolant temperature

sensor signal.

• Malfunction of the torque converter.
• Dirtiness around throttle valve.
• Malfunction of the ECM.

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

CAUTION

YES : Refer to Diagnostic Trouble Code Chart

P.13A-48

NO : Check the following item in the data list. Refer to Data

List Reference Table

P.13A-818

a. Item 6: Engine Coolant Temperature Sensor

Then confirm that the malfunction symptom is

eliminated.

AC608435

Data link connector

MB991827

MB991824

MB991910

Content .. 414 415 416 417 ..