Mitsubishi Galant 9G. Manual — part 786

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-586

.

CIRCUIT OPERATION

• The EGR valve power is supplied from the MFI

relay (terminal No. 4).

• The PCM (terminals No. 124, No. 130, No. 136,

No. 142) drives the stepper motor by sequentially
turning "ON" the power transistors in the PCM
and providing ground to the idle air control motor
(terminal No. 1, No. 3, No. 4, No. 6).

.

TECHNICAL DESCRIPTION

• To judge if there is open circuit in the EGR valve

(stepper motor) drive circuit, PCM measure the
surge voltage of the EGR valve motor coil.

.

DESCRIPTIONS OF MONITOR METHODS

Off-surge does not occur after stepper motor is oper-

ated on to off.

.

MONITOR EXECUTION

Continuous

.

MONITOR EXECUTION CONDITIONS
(Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored

in memory for the item monitored below)

• EGR stepper motor monitor

Sensor (The sensor below is determined to be

normal)

• Mass airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

• Barometric pressure sensor

• Throttle position sensor

• Accelerator pedal position sensor

• Manifold absolute pressure sensor

.

AK303865

AK303865AB

CONNECTOR: B-105

B-105 (GR)

EXHAUST GAS
RECIRCULATION
VALVE

AK303059

CONNECTOR: B-23

PCM

AB

AIR CLEANER

B-23

AK303803AB

CONNECTOR: B-17X

MFI RELAY

B-17X

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-587

DTC SET CONDITIONS
Logic Flow Chart

.

Check Conditions

• Battery positive voltage is higher than 10.3 volts.

• In a few seconds, just after ignition switch is

turned to the "ON" position from the
"LOCK"(OFF) position. (While EGR valve is ini-
tialized.)

Judgment Criteria

• The EGR valve motor coil surge voltage (battery

positive voltage +2 volts) is not detected for 3
seconds.

Check Conditions

• Battery positive voltage is higher than 10.3 volts.

• EGR valve is in operation after the engine start-

ing process is complete.

Judgment Criteria

• The EGR valve motor coil surge voltage (battery

positive voltage +2 volts) is not detected for 30
seconds.

.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function

− OBD-II Drive Cycle −

Procedure 6

− Other Monitor

P.13A-6

.

.

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

• EGR valve (stepper motor) failed.

• Open or shorted EGR valve (stepper motor) cir-

cuit, harness damage or connector damage.

• PCM failed.

START

END

MALFUNCTION

GOOD

MONITORING

CONDITIONS

WAS SURGE VOLTAGE

(> V

B

+2V) DETECTED?

NO

NO

YES

YES

AK204017

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-588

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

• MB991658: Test Harness Set

• MB991923: Power Plant ECU Check Harness

STEP 1. Check harness connector B-105 at EGR valve for
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 2.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 12.

AK303866

1

2

3

4

5

6

AB

CONNECTOR: B-105

B-105 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-589

STEP 2. Measure the EGR valve motor coil resistance.
(1) Disconnect the EGR valve connector B-105.

(2) Measure the resistance between EGR valve connector

terminal No. 2 and either terminal No. 4 or terminal No. 6.

Standard value: 20

− 24 ohms [at 20°C (68°F)]

(3) Measure the resistance between EGR valve connector

terminal No. 5 and either terminal No. 1 or terminal No. 3.

Standard value: 20

− 24 ohms [at 20°C (68°F)]

Q: Is the measured resistance between 20 and 24 ohms [at

20

°C (68°F)]?

YES : Go to Step 3.
NO : Replace the EGR valve. Then go to Step 12.

AK303866

1

2

3

4

5

6

AB

CONNECTOR: B-105

B-105 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE

1

2 3

4

5 6

1

2 3

4

5 6

AK202951