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Mitsubishi Lancer Evolution X. Manual - part 316

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-329

CIRCUIT OPERATION

• The injector power is supplied from the injector

relay (terminal No. 3).

• The ECM controls the injector by turning the

power transistor in the ECM "ON" and "OFF".

TECHNICAL DESCRIPTION

• The amount of fuel injected by the injector is con-

trolled by the amount of continuity time the coil is
grounded by the ECM.

DESCRIPTIONS OF MONITOR METHODS

The ECM detects open circuit and short malfunction.

MONITOR EXECUTION

Continuous

AK704256

Connectors: A-25X, A-34X

MFI relay

Injector relay

A-34X

A-25X

AK704255AB

Connector: A-39

A-39 (B)

AK704227

Connector: B-09

ECM

B-09 (GR)

AK704266 AB

Connector: B-104

B-104 (GR)

Injector No. 4

AK704258 AB

Connector: C-50

C-50 (B)

AK704259AB

Connectors: C-304, C-317

ETACS-ECU

C-304

C-317

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-330

MONITOR EXECUTION CONDITIONS
(Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored

in memory for the item monitored below)

• Not applicable

Sensor (The sensor below is determined to be

normal)

• Not applicable

DTC SET CONDITIONS <Circuit continuity − open circuit and shorted low>

Logic Flow Chart

Check Condition

• Engine is running.

Judgement Criterion

• The supply voltage is 3 volts or less without the

injector driving for 2 seconds.

Good

Malfunction

Injector voltage < = 3V

Start

Continuous

failure for 2secs

End

Yes

AK700479

Monitoring

condition

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-331

DTC SET CONDITIONS <Circuit continuity − shorted high>

Logic Flow Chart

Check Condition

• Engine is running.

Judgement Criterion

• The coil current is 4.5 ampere or more with the

injector driving for 2 seconds.

FAIL-SAFE AND BACKUP FUNCTION

• None

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function − OBD-II Drive Cycle −

Pattern 23

P.13A-9

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

• No. 4 cylinder injector failed.
• Open or shorted No. 4 cylinder injector circuit,

harness damage or connector damage.

• ECM failed.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: V.C.I.
• MB991827: USB Cable
• MB991910: Main Harness A

• MB991658: Test Harness
• MB992110: Power Plant ECU Check Harness

Good

Malfunction

Current >= 4.5A

End

Yes

AK604332

Start

Yes

Continuous

failure for 2secs

Monitoring
condition

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-332

STEP 1. Using scan tool MB991958, check actuator test
item 1: Injectors.

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 actuator testing mode for

item 1, Injectors.

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

to 95° C (176° F to 203° F).

• The idle should become slightly rougher.

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

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

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

Cope with Intermittent Malfunctions

P.00-15

NO : Go to Step 2.

STEP 2. Check harness connector B-104 at No. 4 cylinder
injector for damage.
Q: Is the harness 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 20.

STEP 3. Check the No. 4 cylinder injector.
(1) Disconnect the No. 4 cylinder injector connector B-104.
(2) Measure the resistance between injector side connector

terminal No. 1 and No. 2.

Standard value: 10.5 − 13.5 Ω [at 20° C (68° F)]

Q: Is the measured resistance between 10.5 and 13.5 Ω [at

20° C (68° F)]?
YES : Go to Step 4.
NO : Replace the No. 4 cylinder injector. Then go to Step

20.

AC608435

Data link connector

MB991827

MB991824

MB991910

AK604038

1 2

Injector side
connector

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