Mitsubishi Galant. Manual — part 258

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-257

•

Barometric pressure is higher than 76 kPa (11
psi).

•

Vehicle speed is 30 km/h (18.7 mph) or more.

•

At least ninety seconds have passed since
manifold differential pressure sensor output
voltage fluctuated 1.5 volts or more.

•

The throttle valve is closed.

•

Volumetric efficiency is lower than 28 percent.

•

Monitoring time: 2 seconds.

Judgement Criteria

•

The intake manifold pressure fluctuations are
minimal. When the EGR solenoid is turned ON.

•

Three monitors during one drive cycle

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

•

EGR valve does not open.

•

EGR control vacuum is too low.

•

EGR solenoid failed.

•

Open or shorted EGR solenoid circuit, or loose
connector.

•

Manifold differential pressure sensor failed.

•

PCM failed.

DIAGNOSIS

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

STEP 1. Check the EGR system
Refer to GROUP 17, Emission Control System

−

Exhaust Gas

Recirculation (EGR) System - EGR System Check (

P.17-91

).

Q: Are there any abnormalities?

YES : Go to Step 2.
NO : Repair it. Then go to Step 3.

STEP 2. Using scan tool MB991502, check data list item 95:
Manifold Differential Pressure Sensor.

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK"(OFF) position before
connecting or disconnecting scan tool MB991502.
(1) Connect scan tool MB991502 to the data link connector.
(2) Start the engine and run at idle.
(3) Set scan tool MB991502 to the data reading mode for item

95, Manifold Differential Pressure Sensor.

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

°

C to 96

°

C(176

°

F to 205

°

F).

•

Should be between 62

−

76 kPa at engine idling.

(5) Turn the ignition switch to the "LOCK"(OFF) position.

Q: Is the sensor operating properly?

YES : Clean the EGR valve and EGR passage. Then go to

Step 3.

NO : Refer to, DTC P1400

−

Manifold Differential Pressure

Sensor Circuit Malfunction(

P.13B-372

).

STEP 3. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to,

Procedure 5

−

Exhaust Gas Recirculation (EGR) System

Monitor(

P.13B-4

).

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

Q: Is the DTC P0401 is output?

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

AC003081 AB

16 PIN

MB991502

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-258

DTC P0403: Exhaust Gas Recirculation Solenoid Malfunction

AK000514

3 4

1 2

RED-

WHITE

RED-

WHITE

RED-

WHITE

BLUE-BLA

CK

RED

BATTERY

MFI
RELAY

A-21X

EGR SOLENOID

1

1

2

2

3

4

6

POWERTRAIN CONTROL
MODULE(PCM)

C-39
(MU803784)

2

3 4

5 6

7 8

9

11 12 13 14 15 16 17 18 19 20

30

2122 23

24 25

26 27 28 29

31 32 33

34 35

1

10

2

1

B-03

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-259

TECHNICAL DESCRIPTION

•

The EGR solenoid power is supplied from the
MFI relay (terminal 1).

•

The PCM controls the EGR solenoid ground by
turning the power transistor in the PCM "ON" and
"OFF."

BACKGROUND

•

The PCM checks current flows in the EGR
solenoid drive circuit when the EGR solenoid is
"ON" and "OFF."

DTC SET CONDITIONS

Check Conditions

•

Battery positive voltage is higher than 10 volts.

Judgment Criteria

•

The EGR solenoid coil surge voltage (battery
positive voltage + 2 volts) is not detected when
the EGR solenoid is turned from "ON" to "OFF."

•

Only one monitor during one drive cycle

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

•

EGR solenoid failed.

•

Open or shorted EGR solenoid circuit, or loose
connector.

•

PCM failed.

DIAGNOSIS

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

ACX02514

CONNECTOR:B-03

EGR
SOLENOID
VALVE

AH

AK000280

CONNECTOR : C-39

PCM

AW

AK000555AB

CONNECTOR : A-21X

MFI RELAY

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-260

STEP 1. Using scan tool MB991502, check actuator test
item 10: EGR solenoid.

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK"(OFF) position before
connecting or disconnecting scan tool MB991502.
(1) Connect scan tool MB991502 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991502 to the actuator test mode for item

10, EGR solenoid.

•

An operation sound should be heard and vibration
should be felt when the EGR solenoid is operated.

(4) Turn the ignition switch to the "LOCK"(OFF) position.

Q: Is the solenoid operating properly?

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

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

P.00-8

).

NO : Go to Step 2.

STEP 2. Check connector B-03 at the EGR solenoid for
damage.
Q: Is the connector in good condition?

YES : Go to Step 3.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection(

P.00E-2

). Then go to Step 12.

AC003081 AB

16 PIN

MB991502

ACX02514

CONNECTOR:B-03

EGR
SOLENOID
VALVE

AH