Mitsubishi Eclipse. Manual - part 135

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-33

DTC SET CONDITIONS <Range/Performance problem-high input>

Logic Flow Chart

Check Conditions

• Throttle position sensor output voltage is 2 volts 

or lower.

• Engine speed is lower than 2,000 r/min.

Judgement Criteria

• Volume airflow sensor output frequency has con-

tinued to be 800 Hz or higher for 2 seconds.

.

START

MONITORING

CONDITIONS

END

NO

YES

NO

YES

NO

YES

MALFUNCTION

GOOD

OUTPUT FREQUENCY

> =800Hz

CONTINUOUS

FAILURE FOR 2 secs

AK301411

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-34

DTC SET CONDITIONS <Range/Performance problem-low input>

Logic Flow Chart

Check Conditions

• Throttle position sensor output voltage is 1.5 volts 

or higher.

• Engine speed is higher than 2,000 r/min.

Judgement Criteria

• Volume airflow sensor output frequency has con-

tinued to be 60 Hz or lower for 2 seconds.

.

OBD-ll DRIVE CYCLE PATTERN
Refer to Diagnostic Function 

− OBD-ll Drive Cycle − 

Procedure 6 

− Other Monitor 

P.13A-5

.

.

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

• Volume airflow sensor failed.

• Open or shorted volume airflow sensor circuit, or 

connector damage.

• ECM failed. <M/T>

• PCM failed. <A/T>

DIAGNOSIS

Required Special Tools:

• MB991958 (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991911: Main Harness B

START

MONITORING

CONDITIONS

END

NO

YES

NO

YES

NO

YES

MALFUNCTION

GOOD

OUTPUT FREQUENCY

< =60Hz

CONTINUOUS

FAILURE FOR 2 secs

AK301412

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-35

STEP 1. Using scan tool MB991958, check data list item 12: 
Volume 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 

12, Volume Airflow Sensor.

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

°C 

to 96

°C (176°F to 205°F).

• The standard value during idling should be 10 Hz or 

more.

• When the engine is revved, the frequency should 

increase according to the increase in engine speed.

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

YES : It can be assumed that this malfunction is intermittent. 

Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

P.00-6

.

NO :  Go to Step 2.

STEP 2. Measure the reset signal voltage at volume airflow 
sensor connector B-14 by backprobing.
(1) Do not disconnect the connector B-14.
(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 7 and ground by 

backprobing.

• Voltage should be between 6.0 and 9.0 volts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 6.0 and 9.0 volts?

YES : Go to Step 5.
NO :  Go to Step 3.

AK300810

AB

MB991911

16-PIN

MB991827

MB991824 

AK300078

3

4

5

1

2

6

7

CONNECTOR: B-14

AB

B-14 (B)

HARNESS 
CONNECTOR:
COMPONENT SIDE

AKX01515 AG

B-14 HARNESS
CONNECTOR:
HARNESS SIDE

1 2 3 4 5 6 7

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-36

STEP 3. Check connector B-14 at volume airflow sensor 
and connector C-49 at ECM <M/T> or connector C-50 at 
PCM <A/T> for damage.
Q: Is the connector in good condition?

YES : Go to Step 4.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 9.

AK300078

3

4

5

1

2

6

7

CONNECTOR: B-14

AB

B-14 (B)

HARNESS 
CONNECTOR:
COMPONENT SIDE

AK300413

1

14

4

19

5

22

6

17

8

15

9

18

7

20

16

2

21

23

26

24

25

3

10

11

12

13

CONNECTOR: C-49 <M/T>

C-49 (G)

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AK300414

2

3

4

5

6

7

8

9

11

12

13

14

15

16

17

18

19

20

30

21

22

23

24

25

26

27

28

29

31

32

33

34

35

1

10

C-50 (GR)

CONNECTOR: C-50 <A/T>

AB

HARNESS CONNECTOR:
COMPONENT SIDE