Mitsubishi Lancer Evolution X. Manual - part 425

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-765

STEP 10. Check for continuity at ETACS-ECU side 
connector C-304 and C-317.
(1) Disconnect the connector C-304, C-317 and measure at the 

ETACS-ECU side.

(2) Measure the resistance between connector C-304 (terminal 

No. 10) and connector C-317 (terminal No. 6).
NOTE: Connect the (+) side of circuit tester to connector 
C-304 (terminal No. 10).

• Should be less than 2 ohms

Q: Is the harness wire in good condition?

YES : Check harness connector C-50 at intermediate 

connector for damage, and repair or replace as 
required. Refer to GROUP 00E, Harness Connector 
Inspection 

P.00E-2

. If intermediate connector is in 

good condition, repair harness wire between 
ETACS-ECU connector C-304 (terminal No. 10) and 
ECM connector B-10 (terminal No. 92) because of 
open circuit or short circuit to ground. Then confirm 
that the malfunction symptom is eliminated.

NO :  Replace the ETACS-ECU. Then confirm that the 

malfunction symptom is eliminated.

STEP 11. Check harness connector C-304, C-317 at 
ETACS-ECU connector for damage.
Q: Is the connector in good condition?

YES : Go to Step 12.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then confirm that the 

malfunction symptom is eliminated.

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AK704304

C-317 ETACS-ECU
side connector

C-304 ETACS-ECU
side connector

(  )

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AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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STEP 12. Check for continuity at ETACS-ECU side 
connector C-304 and C-317.
(1) Disconnect the connector C-304, C-317 and measure at the 

ETACS-ECU side.

(2) Measure the resistance between connector C-304 (terminal 

No. 10) and connector C-317 (terminal No. 6).
NOTE: Connect the (+) side of circuit tester to connector 
C-304 (terminal No. 10).

• Should be less than 2 ohms

Q: Is the harness wire in good condition?

YES : Go to Step 13.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

.

STEP 13. Check harness connector C-210 ignition switch 
connector for damage.
Q:  Is the connector in good condition?

YES : Go to Step 14.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then confirm that the 

malfunction symptom is eliminated.

STEP 14. Check for harness damage between ignition 
switch connector C-210 (terminal No. 2) and ETACS-ECU 
connector C-317 (terminal No. 6).
Q: Is the harness wire in good condition?

YES : Go to Step 15.
NO :  Repair it. Then confirm that the malfunction symptom 

is eliminated.

STEP 15. Check for harness damage between ETACS-ECU 
connector C-304 (terminal No. 10) and ECM connector B-10 
(terminal No. 92).
Q: Is the harness wire in good condition?

YES : Go to Step 16.
NO :  Repair it. Then confirm that the malfunction symptom 

is eliminated.

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AK704304

C-317 ETACS-ECU
side connector

C-304 ETACS-ECU
side connector

(  )

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AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-767

STEP 16. Measure the backup power supply voltage at 
ECM harness side connector B-10.
(1) Disconnect the connector B-10 and measure at the harness 

side.

(2) Measure the voltage between terminal No. 104 and ground.

• Voltage should be battery positive voltage.

Q: Is battery positive voltage (approximately 12 volts) 

present?
YES : Go to Step 17.
NO :  Repair harness wire between fusible link (36) and 

ECM connector B-10 (terminal No. 104) because of 
short circuit to ground. Then confirm that the 
malfunction symptom is eliminated.

STEP 17. Check for continuity at ECM harness side 
connector B-10.
(1) Disconnect the connector B-10 and measure at the harness 

side.

(2) Check for the continuity between terminals (No. 81, No. 93) 

and ground.

• Continuity (2 Ω or less)

Q: Does continuity exist?

YES : Go to Step 18.
NO :  Repair harness wire between ECM connector B-10 

(terminal No. 81, No. 93) and ground because of open 
circuit or harness damage. Then confirm that the 
malfunction symptom is eliminated.

AK604223

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B-10 harness
connector: component side

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AK704306 AC

B-10 harness
connector:
component side

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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STEP 18. Measure the power supply voltage at ECM 
harness side connector B-10.
(1) Disconnect the connector B-10 and measure at the harness 

side.

(2) Measure the voltage between terminal No. 73 and ground.

• Voltage should be battery positive voltage.

Q: Is battery positive voltage (approximately 12 volts) 

present?
YES : Go to Step 19.
NO :  Repair harness wire between MFI relay connector 

A-34X (terminal No. 1) and ECM connector B-10 
(terminal No. 73) because of open circuit. Then 
confirm that the malfunction symptom is eliminated.

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AK604047 AC

B-10 harness
connector:
component side