Mitsubishi Eclipse. Manual - part 565

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-803

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991911: Main Harness B

• MB991709: Test Harness

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) Set scan tool MB991958, read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC P0507 set?

YES : Refer to Diagnostic Trouble Code Chart 

P.13B-23

.

NO :  Go to Step 2.

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

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

STEP 3. Check connector B-34 at idle air control motor 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 14.

AK300810

AB

MB991911

16-PIN

MB991827

MB991824 

AK300438

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) <3.0L>

13B-804

STEP 4. Check the idle air control motor coil resistance.
(1) Disconnect the idle air control motor connector B-34.

(2) Measure the resistance between idle air control motor 

connector terminal No. 2 and either terminal No. 1 or 
terminal No. 3.

Standard value: 28 

− 33 ohms [at 20°C (68°F)]

(3) Measure the resistance between idle air control motor 

connector terminal No. 5 and either terminal No. 4 or 
terminal No. 6.

Standard value: 28 

− 33 ohms [at 20° C (68° F)]

Q: Is the measured resistance between 28 and 33 ohms?

YES : Go to Step 5.
NO :  Replace the idle air control motor. Then go to Step 14.

AK300438

1

2

3

4

5

6

CONNECTOR: B-34

AB

B-34 (B)

HARNESS CONNECTOR:
COMPONENT SIDE

AKX01561

1 2 3
4 5 6

1 2 3
4 5 6

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-805

STEP 5. Check the power supply voltage at idle air control 
motor harness side connector B-34.
(1) Disconnect the connector B-34 and measure at the harness 

side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 2, No. 5 and 

ground.

• Voltage should be battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is battery positive voltage (approximately 12 volts) 

present?
YES : Go to Step 7.
NO :  Go to Step 6.

STEP 6. Check connector A-18X at MFI relay for damage.
Q: Is the connector in good condition?

YES : Repair harness wire between MFI relay connector 

A-18X (terminal No. 4) and idle air control motor 
connector B-34 (terminal No. 2, No. 5) because of 
open circuit or short circuit to ground. Then go to Step 
14.

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

Connector Inspection 

P.00E-2

. Then go to Step 14.

AK300438

1

2

3

4

5

6

CONNECTOR: B-34

AB

B-34 (B)

HARNESS CONNECTOR:
COMPONENT SIDE

AKX01428

3 2 1

B-34 HARNESS 
CONNECTOR: 
HARNESS SIDE

AO

6 5 4

AK300454

2

1

3

4

CONNECTOR: A-18X

AB

A-18X

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-806

STEP 7. Check the power supply voltage at ECM connector 
C-51 <M/T> or PCM connector C-52 <A/T> by backprobing.
(1) Do not disconnect the connector C-51 <M/T> or C-52 

<A/T>.

(2) Measure the voltage between terminals No. 14, No. 15, No. 

28, No. 29 and ground by backprobing.

• The voltage is 1 volt or lower for approximately 3 sec-

onds, then changes to the battery positive voltage when 
the Ignition switch is turned from the "LOCK" (OFF) 
position to the "ON" position.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?

YES : Go to Step 10.
NO :  Go to Step 8.

AK300458

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

CONNECTOR: C-52 <A/T>

C-52 (GR)

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AK300443

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

CONNECTOR: C-51 <M/T>

C-51 (GR)

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AKX01550

1

2

3 4

5 6

7 8

10 11 12 13 14 15 16 17 18 19 20 21 22 23

24 25

26 27 28 29

30 31 32 33

34 35

C-51<M/T>, C-52<A/T>
HARNESS CONNECTOR:
HARNESS
SIDE 

AG

9