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

Required Special Tools: 

  1. STEP 1. Using scan toll MB991958, read the MFI system diagnostic trouble code. 
    CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool 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 To Data Link Connector
      G02367439Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Turn the ignition switch "ON" to position.
    3. Read the MFI system diagnosis code.
    NOTE: If the scan tool MB991958 cannot communicate with the MFI system, Refer to SYMPTOM PROCEDURES .

    Q: Is an MFI system DTC P0513 output? 

    1. YES:  Refer to DIAGNOSTIC TROUBLE CODE CHART .
    2. NO:  Go to Step 2.
  2. STEP 2. Check the immobilizer-ECU power supply circuit by backprobing. 
    1. Do not disconnect immobilizer-ECU connector C-39.
      Fig 2: Identifying Immobilizer-ECU Connector C-39
      G02367440Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Turn the ignition switch to the "ON" position.
    3. Measure the voltage between terminal 1 and ground by backprobing.
      • The voltage should measure approximately 12 volts (battery positive voltage).
        Fig 3: Measuring Voltage Between Terminal 1 And Ground
        G02367441Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Is the measured voltage approximately 12 volts (battery positive voltage)? 

    1. YES:  Go to  Step 5.
    2. NO:  Go to Step 3.
  3. STEP 3. Check immobilizer-ECU connector C-39 and MFI relay connector B-15X for loose, corroded or damaged terminals, or terminals pushed back in the connector. 
    Fig 4: Identifying MFI Relay Connector B-15X
    G02367442Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 5: Identifying Immobilizer-ECU Connector C-39
    G02367443Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Are immobilizer-ECU connector C-39 and MFI relay connector B-15X in good condition? 

    1. YES:  Go to Step 4.
    2. NO:  Repair or replace the component(s). Refer to HARNESS CONNECTOR INSPECTION . Confirm that scan tool MB991958 communicates normally.
  4. STEP 4. Check the wiring harness between immobilizer-ECU connector C-39 (terminal 1) and MFI relay connector B-15X (terminal 4). 
    Fig 6: Identifying MFI Relay Connector B-15X
    G02367444Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 7: Identifying Immobilizer-ECU Connector C-39
    G02367445Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    NOTE: Also check intermediate connector A-13 and C-31, check the wires. If intermediate connector A-13 or C-31 are damaged, repair or replace them. Refer to HARNESS CONNECTOR INSPECTION .
    Fig 8: Identifying Intermediate Connector A-13
    G02367446Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 9: Identifying Intermediate Connector A-31
    G02367447Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 10: Identifying Connector C-310
    G02367448Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Are the wiring harness between immobilizer-ECU connector C-39 (terminal 1) and MFI relay connector B-15X (terminal 4) in good condition? 

    1. YES:  There is no action to be taken.
    2. NO:  Repair the wiring harness. Confirm that scan tool MB991958 communicates normally.
  5. STEP 5. Measure the resistance at immobilizer-ECU connector C-39. 
    1. Do not disconnect immobilizer-ECU connector C-39.
      Fig 11: Identifying Immobilizer-ECU Connector C-39
      G02367449Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Measure the resistance between terminal 2 and ground.
      Fig 12: Measuring Resistance Between Terminal 2 And Ground
      G02367450Courtesy 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 6.
  6. STEP 6. Check immobilizer-ECU connector C-39 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 
    Fig 13: Identifying Immobilizer-ECU Connector C-39
    G02367451Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Is immobilizer-ECU connector C-39 in good condition? 

    1. YES:  Go to Step 7.
    2. NO:  Repair or replace the component(s). Refer to HARNESS CONNECTOR INSPECTION . Confirm that scan tool MB991958 communicates normally.
  7. STEP 7. Check the wiring harness between immobilizer-ECU connector C-39 (terminal 2) and ground. 
    Fig 14: Identifying Immobilizer-ECU Connector C-39 And Ground
    G02367452Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    NOTE: Also check joint connector (2) C-104, check the wires. If joint connector (2) C-104 is damaged, repair or replace it. Refer to HARNESS CONNECTOR INSPECTION .
    Fig 15: Identifying Joint Connector C-104
    G02367453Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Is the wiring harness between immobilizer-ECU connector C-39 (terminal 2) and ground in good condition? 

    1. YES:  There is no action to be taken.
    2. NO:  Repair the wiring harness. Confirm that scan tool MB991958 communicates normally.
  8. STEP 8. Check immobilizer-ECU connector C-39 and PCM connector B-18 for loose, corroded or damaged terminals, or terminal pushed back in the connector. 
    Fig 16: Identifying PCM Connector B-18
    G02367454Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 17: Identifying Immobilizer-ECU Connector C-39
    G02367455Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Are immobilizer-ECU connector C-39 and PCM connector B-18 in good condition? 

    1. YES:  Go to Step 9.
    2. NO:  Repair or replace the component(s). Refer to HARNESS CONNECTOR INSPECTION . Confirm that scan tool MB991958 communicates normally.
  9. STEP 9. Check the wiring harness between immobilizer-ECU connector C-39 (terminal 3) and PCM connector B-18 (terminal 13). 
    Fig 18: Identifying PCM Connector B-18
    G02367456Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 19: Identifying Immobilizer-ECU Connector C-39
    G02367457Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Are the wiring harness between immobilizer-ECU connector C-39 (terminal 3) and PCM connector B-18 (terminal 13) in good condition? 

    1. YES:  Go to Step 10.
    2. NO:  Repair the wiring harness. Confirm that scan tool MB991958 communicates normally.
  10. STEP 10. Replace the immobilizer-ECU or PCM. 

    Replace the immobilizer-ECU or PCM.

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

    1. YES:  Register the password (secret code) and encrypted code P.54A-39.
    2. NO:  Replace the PCM. Then register the password (secret code) and encrypted code (Refer to ON-VEHICLE SERVICE  ).
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