INSPECTION PROCEDURE 1: Communication with Scan Tool MB991958 is Impossible.: Diagnosis

Required Special Tools: 

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (V.C.I.)
  • MB991827: M.U.T.-III USB Cable
  • MB991911: M.U.T.-III Main Harness B

1. STEP 1. Using scan tool MB991958, read the MFI system diagnostic trouble code. 
   CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502 or MB991958.

   Use scan tool MB991958 to confirm the MFI system DTC.

   1. Connect scan tool MB991958 to the data link connector.
   2. Turn the ignition switch "ON" position.
   3. Read the MFI system diagnosis code.

   Q: Can scan tool MB991958 communicate with the MFI system? Is an MFI system DTC other than P0513 output? 

   YES:  Go to Step 2.

   NO:  Refer to MULTIPORT FUEL INJECTION (MFI) - LANCER EVOLUTION .

   Fig 1: Connecting Scan Tool To Data Link Connector

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Check immobilizer-ECU connector C-22 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Is immobilizer-ECU connector C-22 in good condition? 

   YES:  Go to Step 3.

   NO:  Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION . Confirm that scan tool MB991958 communicates normally.

   Fig 2: Identifying Immobilizer-ECU Connector C-22

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3. STEP 3. Check the battery power supply (MFI relay) circuit to the immobilizer-ECU. Measure the voltage at immobilizer-ECU connector C-22. 
   1. Disconnect immobilizer-ECU connector C-22 and measure the voltage available at the wiring harness side of the connector.
   2. Turn the ignition switch to the "ON" position.
      Fig 3: Identifying Immobilizer-ECU Connector C-22

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   3. Measure the voltage between terminal 7 and ground.

   Q: Is battery voltage (approximately 12 volts) present? 

   YES:  Go to  Step 6.

   NO:  Go to Step 4.

   Fig 4: Measuring Voltage Between Terminal 7 And Ground

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4. STEP 4. Check MFI relay connector B-12X for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Is MFI relay connector B-12X in good condition? 

   YES:  Go to Step 5.

   NO:  Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION . Confirm that scan tool MB991958 communicates normally.

   Fig 5: Identifying MFI Relay Connector B-12X

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5. STEP 5. Check the harness wires between immobilizer-ECU connector C-22 (terminal 7) and MFI relay connector B-12X (terminal 4). 
   Fig 6: Identifying MFI Relay Connector B-12X

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   Fig 7: Identifying Immobilizer-ECU Connector C-22

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   NOTE: Also check intermediate connector C-123, joint connector C-21 and C-105 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-123, joint connector C-21 or C-105 is damaged, Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .

   Q: Are the harness wires between immobilizer-ECU connector C-22 (terminal 7) and MFI relay connector B-12X (terminal 4) in good condition? 

   YES:  There is no action to be taken.

   NO:  Replace damaged component(s). Confirm that scan tool MB991958 communicates normally.

6. STEP 6. Check the ground circuit to the immobilizer-ECU. Measure the resistance at immobilizer-ECU connector C-22. 
   1. Disconnect immobilizer-ECU connector C-22 and measure the resistance available at the wiring harness side of the connector.
      Fig 8: Identifying Immobilizer-ECU Connector C-22

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   2. Measure the resistance between terminal 3 and ground.

   Q: Is the resistance less than 2 ohms? 

   YES:  Go to  Step 8.

   NO:  Go to Step 7.

   Fig 9: Measuring Resistance Between Terminal 3 And Ground

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7. STEP 7. Check the harness wire between immobilizer-ECU connector C-22 (terminal 3) and ground. 
   Fig 10: Identifying Immobilizer-ECU Connector C-22

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
   NOTE: Also check joint connector C-06 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector C-06 is damaged, Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .

   Q: Is the harness wire between immobilizer-ECU connector C-22 (terminal 3) and ground in good condition? 

   YES:  There is no action to be taken.

   NO:  Repair or replace the damaged component(s). Confirm that scan tool MB991958 communicates normally.

   Fig 11: Identifying Joint Connector C-06

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
8. STEP 8. Check ECM connector C-117 for loose, corroded or damaged terminals, or terminal pushed back in the connector. 

   Q: Is ECM connector C-117 in good condition? 

   YES:  Go to Step 9.

   NO:  Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION . Confirm that scan tool MB991958 communicates normally.

   Fig 12: Identifying ECM Connector C-117

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9. STEP 9. Check the harness wires between immobilizer-ECU connector C-22 (terminal 5) and ECM connector C-117 (terminal 98). 
   Fig 13: Identifying ECM Connector C-117

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   Fig 14: Identifying Immobilizer-ECU Connector C-22

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   NOTE: Also check intermediate connector C-124 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-124 is damaged, Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .

   Q: Are the harness wires between immobilizer-ECU connector C-22 (terminal 5) and ECM connector C-117 (terminal 98) in good condition? 

   YES:  Go to Step 10.

   NO:  Repair or replace the damaged component(s). Confirm that scan tool MB991958 communicates normally.

10. STEP 10. Replace the immobilizer-ECU or ECM. 

    Replace the immobilizer-ECU or ECM.

    Q: Did the communication with the scan tool become possible after replacing the immobilizer-ECU or the engine control module? 

    YES:  Register the password (secret code) and encrypted code HOW TO REGISTER ENCRYPTED CODE  . Confirm that scan tool MB991958 communicates normally

    NO:  Go to Step 11.

11. STEP 11. Recheck for malfunction. 

    Q: Is a malfunction eliminated? 

    YES:  The procedure is complete. (If no malfunctions are found in all steps, an intermittent malfunction is suspected. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).

    NO:  Replace the immobilizer-ECU or ECM.