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Mitsubishi Lancer Evolution X. Manual - part 400

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-665

DTC SET CONDITIONS <Range/Performance problem -relation between main and
sub>

Logic Flow Chart

Check Conditions

• Change of accelerator pedal position sensor

(sub) output voltage per 25 milliseconds is lower
than 0.06 volt.

Judgement Criterion

• Voltage obtained with the formula given below is

0.4 volt or higher for 0.2 second: [accelerator
pedal position sensor (main) voltage − accelerator

pedal position sensor (sub) voltage].

NOTE: The accelerator pedal position sensor
voltage used for the judgement is converted into
the accelerator pedal position sensor voltage for
the internal processing by the ECM.

FAIL-SAFE AND BACKUP FUNCTION

• Throttle opening degree is restricted.
• Throttle opening degree position is in default

position if accelerator pedal position sensor (sub)
fails.

AK604364

Start

Yes

{APS (main) - APS (sub)}

>= 0.4V

Continuous

failure for 0.2sec

Malfunction

End

Good

Monitoring
conditions

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-666

OBD-II DRIVE CYCLE PATTERN

None.

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

• Accelerator pedal position sensor failed.
• Harness damage in accelerator pedal position

sensor circuit 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

STEP 1. Check harness connector C-01 at accelerator
pedal position sensor 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 16.

STEP 2. Check the continuity at accelerator pedal position
sensor harness side connector C-01.
(1) Disconnect the connector C-01 and measure at the harness

side.

(2) Measure the continuity between terminal No. 2 and ground.

• Continuity (2 ohms or less)

Q: Does continuity exist?

YES : Go to Step 6.
NO : Go to Step 3.

STEP 3. Check harness connector B-10 at ECM for
damage.
Q: Is the harness 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 16.

STEP 4. Check for harness damage between accelerator
pedal position sensor connector C-01 (terminal No. 2) and
ECM connector B-10 (terminal No. 76).
Q: Is the harness wire in good condition?

YES : Go to Step 5.
NO : Repair it. Then go to Step 16.

AK704747

6 5 4 3 2

C-01 harness
connector:
component side

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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STEP 5. 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) After the DTC has been deleted, read the DTC again.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC P2138 set?

YES : Replace the ECM. When the ECM is replaced,

P.42B-11

or GROUP 42C, ID Codes

Registration Judgment Table <Vehicles with WCM>

P.42C-9

. Then go to Step 16.

NO : 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

STEP 6. Check the continuity at accelerator pedal position
sensor harness side connector C-01.
(1) Disconnect the connector C-01 and measure at the harness

side.

(2) Measure the continuity between terminal No. 5 and ground.

• Continuity (2 ohms or less)

Q: Does continuity exist?

YES : Go to Step 10.
NO : Go to Step 7.

STEP 7. Check harness connector B-10 at ECM for
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 8.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 16.

AC608435

Data link connector

MB991827

MB991824

MB991910

AK704745

6 5 4 3 2

C-01 harness
connector:
component side

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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STEP 8. Check for harness damage between accelerator
pedal position sensor connector C-01 (terminal No. 5) and
ECM connector B-10 (terminal No. 79).
Q: Is the harness wire in good condition?

YES : Go to Step 9.
NO : Repair it. Then go to Step 16.

STEP 9. Using scan tool MB991958, read the diagnostic
trouble code (DTC).

CAUTION

YES : Replace the ECM. When the ECM is replaced,

P.42B-11

or GROUP 42C, ID Codes

Registration Judgment Table <Vehicles with WCM>

P.42C-9

. Then go to Step 16.

NO : 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

STEP 10. Check harness connector B-10 at ECM for
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 11.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 16.

STEP 11. Check for harness damage between accelerator
pedal position sensor connector C-01 (terminal No. 1) and
ECM connector B-10 (terminal No. 75).
Q: Is the harness wire in good condition?

YES : Go to Step 12.
NO : Repair it. Then go to Step 16.

AC608435

Data link connector

MB991827

MB991824

MB991910

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