Mitsubishi Eclipse. Manual - part 321

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-777

STEP 12. Check the ignition timing.
Refer to GROUP 11A, On-vehicle Service 

− Ignition Timing 

Check 

P.11A-7

.

Q: Is the ignition timing normal?

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

defective items.

a. Check the ignition coil, spark plugs, spark plug 

cables.

b. Check the purge control system.

c. Check compression pressure.

d. Check if the foreign materials (water, 

kerosene, etc.) got into fuel.

e. Check the EGR control system.

Then confirm that the malfunction symptom is 

eliminated.

NO :  Check that the crankshaft position sensor and timing 

belt cover are in the correct position. Then confirm 
that the malfunction symptom is eliminated.

INSPECTION PROCEDURE 9: 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 IAC system.

• Malfunction of the throttle body.

DIAGNOSIS

Required Special Tools:

• MB991958 (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991911: Main Harness B

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-778

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 DTC set?

YES : Refer to, Diagnostic Trouble Code Chart 

P.13A-24

.

NO :  Go to Step 2.

STEP 2. Check the idle air control (IAC) motor operation 
sound.
(1) Check that the engine coolant temperature is 20

°C (68°F) 

or below.
NOTE: Disconnecting the engine coolant temperature sen-
sor connector and connecting the harness side of the con-
nector to another engine coolant temperature sensor that is 
at 20

°

C (68

°

F) or below is also okay.

(2) Check the operation sound of the IAC motor can be heard 

after the ignition is switched to the "ON" position (but 
without starting the engine).

• An operation sound should be heard.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Did you hear the operation sound?

YES : Go to Step 3.
NO :  Refer to, DTC P0506 

− Idle Control System RPM 

Lower Than Expected 

P.13A-625

, DTC P0507 

− Idle 

Control System RPM Higher Than Expected 

P.13A-640

.

AK300810

AB

MB991911

16-PIN

MB991827

MB991824 

AK300408

1

2

3

4

5

6

CONNECTOR: B-34

AB

B-34 (B)

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-779

STEP 3. Using scan tool MB991958, check data list.

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) Check the following items in the data list. Refer to, Data List 

Reference Table 

P.13A-892

.

a. Item 21: Engine Coolant Temperature Sensor.
b. Item 28: A/C Switch.

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

YES : Go to Step 4.
NO :  Repair or replace. Then confirm that the malfunction 

symptom is eliminated.

STEP 4. Adjust the basic idle speed.
Refer to, Basic Idle Speed Adjustment for the adjustment pro-
cedure 

P.13A-928

.

Standard value: 700 

± 50 r/min

Q: Is the Idle speed normal?

YES : Refer to, Clean the throttle valve area 

P.13A-926

.

NO :  The check is completed.

INSPECTION PROCEDURE 10: 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 IAC system.

• Malfunction of the throttle body.

DIAGNOSIS

Required Special Tools:

• MB991958 (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991911: Main Harness B

AK300810

AB

MB991911

16-PIN

MB991827

MB991824 

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-780

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 DTC set?

YES : Refer to, Diagnostic Trouble Code Chart 

P.13A-24

.

NO :  Go to Step 2.

STEP 2. Check the idle air control (IAC) motor operation 
sound.
(1) Check that the engine coolant temperature is 20

°C (68°F) 

or below.
NOTE: If necessary, you can disconnect the engine coolant 
temperature sensor connector and connect the harness 
side of the connector to another engine coolant temperature 
sensor that is at 20

°

C (68

°

F) or below.

(2) Check that the operation sound of the IAC motor can be 

heard after the ignition is switched to the "ON" position (but 
without starting the engine).

• An operation sound should be heard.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Did you hear the operation sound?

YES : Go to Step 3.
NO :  Refer to, DTC P0506 

− Idle Control System RPM 

Lower Than Expected 

P.13A-625

, DTC P0507 

− Idle 

Control System RPM Higher Than Expected 

P.13A-640

.

AK300810

AB

MB991911

16-PIN

MB991827

MB991824 

AK300408

1

2

3

4

5

6

CONNECTOR: B-34

AB

B-34 (B)

HARNESS CONNECTOR:
COMPONENT SIDE