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Inspection Procedure 1: Communication With Scan MB991958 Is Impossible.: Diagnosis

WARNING: This page is about a different variant/trim than selected.

Required Special Tools: 

  1. STEP 1. Check if scan tool MB991958 can communicate with the MFI system and if an MFI system DTC other than P0513 is output. 
    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.
      Fig 1: Connecting Scan Tool MB991958 To Data Link Connector
      G01077478Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    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? 

    1. YES:  Go to Step 2.
    2. NO:  Refer to MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS .
  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? 

    Fig 2: View Of Connector C-22
    G01077479Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    1. YES:  Go to Step 3.
    2. NO:  Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION . Confirm that scan tool MB991958 communicates normally.
  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.
      Fig 3: Locating Connector C-22
      G01077480Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Turn the ignition switch to the "ON" position.
    3. Measure the voltage between terminal 7 and ground.
    Fig 4: Measuring Voltage Between Connector C-22 Terminal 7 And Ground
    G01077481Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

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

    1. YES:  Go to  Step 6.
    2. NO:  Go to Step 4.
  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? 

    Fig 5: View Of Connector B-12X
    G01077482Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    1. YES:  Go to Step 5.
    2. NO:  Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION . Confirm that scan tool MB991958 communicates normally.
  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 Connector B-12X
    G01077483Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 7: Identifying Connector Terminals
    G01077484Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    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? 

    1. YES:  There is no action to be taken.
    2. 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: View Of Connector C-22
      G01077485Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Measure the resistance between terminal 3 and ground.
    Fig 9: Measuring Resistance Between Connector C-22 Terminal 3 And Ground
    G01077486Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Is the resistance less than 2 ohms? 

    1. YES:  Go to  Step 8.
    2. NO:  Go to Step 7.
  7. STEP 7. Check the harness wire between immobilizer-ECU connector C-22 (terminal 3) and ground. 
    Fig 10: Identifying Connector C-22
    G01077487Courtesy 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 .
    Fig 11: Locating Connector C-06
    G01077488Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

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

    1. YES:  There is no action to be taken.
    2. NO:  Repair or replace the damaged component(s). Confirm that scan tool MB991958 communicates normally.
  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? 

    1. YES:  Go to Step 9.
    2. NO:  Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION . Confirm that scan tool MB991958 communicates normally.
    Fig 12: View Of Connector C-117
    G01077489Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  9. STEP 9. Check the harness wires between immobilizer-ECU connector C-22 (terminal 5) and ECM connector C-117 (terminal 51). 
    Fig 13: Identifying Connector Terminals
    G01077490Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 14: Identifying Connector C-117
    G01077491Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    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 51) in good condition? 

    1. YES:  Go to Step 10.
    2. 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? 

    1. YES:  Register the password (secret code) and encrypted code P.54A-37. Confirm that scan tool MB991958 communicates normally
    2. NO:  Go to Step 11.
  11. STEP 11. Recheck for malfunction. 

    Q: Is a malfunction eliminated? 

    1. 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 MALFUNCTIONS ).
    2. NO:  Replace the immobilizer-ECU or ECM.
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