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Home >> Mitsubishi >> 2003 >> Lancer Evolution >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Anti-Theft Systems >> Ignition Switch & Immobilizer System - Evolution >> Immobilizer System Diagnosis >> Symptom Procedures >> INSPECTION PROCEDURE 1: Communication with Scan Tool MB991502 or MB991958 is Impossible. >> Diagnosis
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INSPECTION PROCEDURE 1: Communication with Scan Tool MB991502 or MB991958 is Impossible.: Diagnosis

Required Special Tools: 

  1. STEP 1. Check if scan tool MB991502 or 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 MB991502 or MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502 or MB991958.

    Use scan tool MB991502 or MB991958 to confirm the MFI system DTC.

    1. Connect scan tool MB991502 or MB991958 to the data link connector.
    2. Turn the ignition switch "ON" position.
    3. Read the MFI system diagnosis code.
      Fig 1: Connecting Scan Tool To Data Link Connector
      G01881133Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Can scan tool MB991502 or 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 SELF-DIAGNOSTICS - 2.0L TURBO article.
    Fig 2: Connecting Scan Tool To Data Link Connector And Personal Computer
    G01881134Courtesy 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? 

    1. YES :  Go to Step 3.
    2. NO :  Repair or replace the damaged component(s). Confirm that scan tool MB991502 or MB991958 communicates normally.
    Fig 3: Locating Immobilizer ECU Connector C-22
    G01881135Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  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 4: Locating Immobilizer ECU Connector C-22
      G01881136Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. Measure the voltage between terminal 7 and ground.

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

    1. YES :  Go to Step  6 .
    2. NO :  Go to Step 4.
    Fig 5: Measuring Voltage Between Terminal 7 And Ground (Connector C-22)
    G01881137Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  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? 

    1. YES :  Go to Step 5.
    2. NO :  Repair or replace the damaged component(s). Confirm that scan tool MB991502 or MB991958 communicates normally.
    Fig 6: Locating MFI Relay Connector B 12X
    G01881138Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  5. STEP 5. Check the harness wires between immobilizer-ECU connector C-22 (terminal 7) and MFI relay connector B-12X (terminal 4). 
    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).
    Fig 7: Locating MFI Relay Connector B 12X
    G01881139Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    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 MB991502 or MB991958 communicates normally.
    Fig 8: Locating Connectors C21, C22, C105 And C123
    G01881140Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  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 9: Locating Immobilizer ECU Connector C22
      G01881141Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    2. Measure the resistance between terminal 3 and ground.

    Q: Is the resistance less than 2 ohms? 

    1. YES :  Go to Step  8 .
    2. NO :  Go to Step 7.
    Fig 10: Measuring Resistance Between Terminal 3 And Ground (Connector C22)
    G01881142Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  7. STEP 7. Check the harness wire between immobilizer-ECU connector C-22 (terminal 3) and ground. 
    Fig 11: Locating Immobilizer ECU Connector C-22
    G01881143Courtesy 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).
    Fig 12: Locating Joint Connector C-06
    G01881144Courtesy 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 MB991502 or 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). Confirm that scan tool MB991502 or MB991958 communicates normally.
    Fig 13: Locating ECM Connector C-117
    G01881145Courtesy 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). 
    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).
    Fig 14: Locating Immobilizer ECU Connector C-22 And Intermediate Connector C-124
    G01881146Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    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 MB991502 or MB991958 communicates normally.
    Fig 15: Locating ECM Connector C-117
    G01881147Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  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 ON-VEHICLE SERVICE  . 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 malfunction are not found in all steps, an intermittent malfunction is suspected.
    2. NO :  Replace the immobilizer-ECU or ECM.
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