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INSPECTION PROCEDURE 1: Communication with Scan Tool MB991502 is Impossible: Diagnosis

Required Special Tools: 

  1. STEP 1. Check scan tool MB991502 communicates with the MFI system and MFI system DTC output other than P1610. 

    Q: Can scan tool MB991502 communicate with the MFI system? Does MFI system DTC other than P1610 reset? 

    1. YES:  Go to Step 2.
    2. NO:  Refer to SELF-DIAGNOSTICS - 2.4L or SELF-DIAGNOSTICS - 3.0L .
  2. STEP 2. Check the immobilizer-ECU power supply circuit by backprobing. 
    1. Do not disconnect immobilizer-ECU connector C-79.
    2. Turn the ignition switch to the "ON" position.
      Fig 1: Identifying Immobilizer-ECU Connector C-79 Location And Terminal View
      G01890177Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. Measure the voltage between terminal 7 and ground by backprobing.
      • The measured value should be approximately 12 volts (battery positive voltage).
      Fig 2: Checking Immobilizer-ECU Power Supply Circuit By Backprobing
      G01890178Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Does the measured voltage correspond with this range? 

    1. YES:  Go to Step  5 .
    2. NO:  Go to Step 3.
  3. STEP 3. Check immobilizer-ECU connector C-79 and MFI relay connector A-18X for damage. 

    Q: Are immobilizer-ECU connector C-79 and MFI relay connector A-18X damaged? 

    1. YES:  Repair or replace the connector. Confirm that scan tool MB991502 communicates normally.
    2. NO:  Go to Step 4.
      Fig 3: Identifying MFI Relay Connector A-18X Location And Terminal View
      G01890179Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
      Fig 4: Identifying Immobilizer-ECU Connector C-79 Location And Terminal View
      G01890180Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  4. STEP 4. Check the wiring harness between immobilizer-ECU connector C-79 (terminal 7) and MFI relay connector A-18X (terminal 4). 
    NOTE: After checking intermediate connector C-28, check the wires. If intermediate connector C-28 is damaged, repair or replace the wiring harness.
    Fig 5: Identifying MFI Relay Connector A-18X Location And Terminal View
    G01890181Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 6: Identifying Immobilizer-ECU Connector C-79 Location And Terminal View
    G01890182Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 7: Identifying Connector C-28 Location And Terminal View
    G01890183Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Are the wiring harness between immobilizer-ECU connector C-79 (terminal 7) and MFI relay connector A-18X (terminal 4) damaged? 

    1. YES:  Replace the wiring harness. Confirm that scan tool MB991502 communicates normally.
    2. NO:  There is no action to be taken.
  5. STEP 5. Check the immobilizer-ECU ground circuit by backprobing. 
    1. Do not disconnect immobilizer-ECU connector C-79.
      Fig 8: Identifying Immobilizer-ECU Connector C-79 Location And Terminal View
      G01890184Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Measure the resistance between terminal 3 and ground by backprobing.
      • The measured value should be 2 ohm or less.
      Fig 9: Checking Immobilizer-ECU Ground Circuit By Backprobing
      G01890185Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Does the measured resistance value correspond with this range? 

    1. YES:  Go to Step 6.
    2. NO:  Go to Step  8 .
  6. STEP 6. Check immobilizer-ECU connector C-79 for damage. 

    Q: Is immobilizer-ECU connector C-79 in good condition? 

    1. YES:  Go to Step 7.
    2. NO:  Repair or replace the connector. Confirm that scan tool MB991502 communicates normally.
      Fig 10: Identifying Immobilizer-ECU Connector C-79 Location And Terminal View
      G01890186Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  7. STEP 7. Check the wiring harness between immobilizer-ECU connector C-79 (terminal 3) and ground. 

    Q: Is the wiring harness between immobilizer-ECU connector C-79 (terminal 3) and ground damaged? 

    1. YES:  Repair the wiring harness. Confirm that scan tool MB991502 communicates normally.
    2. NO:  There is no action to be taken.
      Fig 11: Identifying Immobilizer-ECU Connector C-79 Location And Terminal 3 View
      G01890187Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  8. STEP 8. Check the wiring harness between immobilizer-ECU connector C-79 (terminal 5) and ECM connector C-56 (terminal 51) < 2.4L M/T >, C-62 (terminal 98) < 3.0L M/T > or PCM connector C-61 (terminal 111) < 2.4L A/T >, C-63 (terminal 111) < 3.0L A/T >. 

    Q: Are the wiring harness between immobilizer-ECU connector C-79 and ECM connector C-56 (terminal 51) < 2.4L M/T >, C-62 (terminal 98) < 3.0L M/T > or PCM connector C-61 (terminal 111) < 2.4L A/T >, C-63 (terminal 111) < 3.0L A/T > damaged? 

    1. YES:  Repair the wiring harness. Confirm that scan tool MB991502 communicates normally.
    2. NO:  Go to Step 9.
      Fig 12: Identifying Immobilizer-ECU Connector C-79 Location And Terminal 5 View
      G01890188Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
      Fig 13: Identifying ECM Connectors Terminals View
      G01890189Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  9. STEP 9. Replace the immobilizer-ECU. 

    Q: Did the communication with MUT-II become possible after replacing the immobilizer-ECU? 

    1. YES:  Register the password (secret code) and encrypted code (Refer to IMMOBILIZER ENCRYPTED CODE REGISTRATION  ). Confirm that scan tool MB991502 communicates normally.
    2. NO:  Go to Step 10.
  10. STEP 10. Recheck for malfunction 

    Q: Is a malfunction eliminated? 

    1. YES:  Go to Step 11.
    2. NO:  Replace the immobilizer-ECU.
  11. STEP 11. Replace the ECM (M/T) or PCM (A/T). 

    Q: Did the communication with MUT-II become possible after replacing the Engine control module < M/T > or the powertrain control module < A/T >? 

    1. YES:  Register the password (secret code) and encrypted code (Refer to IMMOBILIZER ENCRYPTED CODE REGISTRATION  .). Confirm that scan tool MB991502 communicates normally.
    2. NO:  Go to Step 12.
  12. STEP 12. Recheck for malfunction 

    Q: Is a malfunction eliminated? 

    1. YES:  This diagnosis is complete. If no malfunction are not found in all steps, an intermittent malfunction is suspected. Refer to INTERMITTENTS in TROUBLE SHOOTING - NO CODES - EXCEPT LANCER TURBO .
    2. NO:  Replace the ECM < M/T > or PCM < A/T >.
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