Mitsubishi Galant. Manual — part 280

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-345

STEP 12. Check for harness damage between MFI relay
connector A-21X terminal 1 and idle air control motor
connector B-06 terminal 2, 5.
Q: Is the harness wire in good condition?

YES : Go to Step 13.
NO : Repair it. Then go to Step 14.

STEP 13. Check for harness damage between idle air
control motor connector B-06 and PCM connector C-39.

a. Idle air control motor connector B-06 terminal 1 and PCM

connector C-39 terminal 14.

b. Idle air control motor connector B-06 terminal 3 and PCM

connector C-39 terminal 28.

c. Idle air control motor connector B-06 terminal 4 and PCM

connector C-39 terminal 15.

d. Idle air control motor connector B-06 terminal 6 and PCM

connector C-39 terminal 29.

Q: Is the harness wire in good condition?

YES : Replace the PCM. Then go to Step 14.
NO : Repair it. Then go to Step 14.

AK000555AB

CONNECTOR : A-21X

MFI RELAY

ACX02523AG

IDLE AIR
CONTROL
MOTOR

CONNECTOR:B-06

ACX02523AG

IDLE AIR
CONTROL
MOTOR

CONNECTOR:B-06

AK000280

CONNECTOR : C-39

PCM

AW

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-346

STEP 14. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to,

Procedure 6

−

Other Monitor(

P.13B-4

).

(2) Check the diagnostic trouble code (DTC).

Q: Is the DTC P0506 is output?

YES : Retry the troubleshooting.
NO : The inspection is complete.

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-347

DTC P0507: Idle Control System RPM Higher Than Expected

AK000515

1 2
3 4

1 2
4 5 6

3

RED-

WHITE

RED-

WHITE

RED-

WHITE

RED

RED

RED

RED-BLA

CK

BR

O

WN-WHITE

GREEN-YELLO

W

BLA

CK-YELLO

W

B-06

IDLE AIR
CONTROL(IAC)
MOTOR

A-21X

BATTERY

MFI
RELAY

1

1

2

2

3

3

4

4

5

6

POWERTRAIN CONTROL
MODULE(PCM)

14

28

15

29

C-39
(MU803784)

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

3132 33

34 35

1

10

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-348

CIRCUIT OPERATION

•

The idle air control motor power is supplied from
the MFI relay (terminal 1).

•

The PCM (terminals 14, 15, 28, 29) drives the
stepper motor by sequentially turning "ON" the
power transistors in the PCM and providing
ground to the idle air control motor (terminals 1,
3, 4, 6).

TECHNICAL DESCRIPTION

•

The amount of air taken in during idling is
regulated by the opening and closing of the servo
valve located in the air passage that bypasses
the throttle body.

•

If there is a malfunction of the IAC system, the
actual engine speed will not be identical to the
target engine speed.

•

The PCM checks the difference between the
actual engine speed and the target engine speed.

DTC SET CONDITIONS

Check Conditions

•

Vehicle speed has reached 1.5 km/h (0.93 mph)
or more at least once.

•

Under the closed loop idle speed control.

Judgment Criteria

•

Actual idle speed has continued to be higher than
the target idle speed by 300 r/min or more for 12
seconds.

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

•

Idle air control motor failed.

•

Open or shorted idle air control motor circuit, or
loose connector.

•

PCM failed.

DIAGNOSIS

Required Special Tools
MB991502: Scan Tool (MUT-II)
MB991709: Test harness

ACX02523AG

IDLE AIR
CONTROL
MOTOR

CONNECTOR:B-06

AK000555AB

CONNECTOR : A-21X

MFI RELAY

AK000280

CONNECTOR : C-39

PCM

AW