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Home >> Mitsubishi >> 2013 >> Lancer Evolution MR >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 1 (MITSUBISHI Multi-Communication System (MMCS) - Lancer Evolution) >> Symptom Procedures >> Inspection Procedure 12: Check The CAN Box Unit Power Supply Circuit >> Diagnosis
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Inspection Procedure 12: Check The CAN Box Unit Power Supply Circuit: Diagnosis

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

Required Special Tools: 

  1. STEP 1. Check CAN box unit connectors C-15 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

    Q: Is CAN box unit connectors C-15 in good condition? 

  2. STEP 2. Check the ground circuit to the CAN box unit. Measure the resistance at CAN box unit connector C-15. 
    1. Disconnect CAN box unit connector C-15 and measure the resistance available at the wiring harness side of the connector.
    2. Measure the resistance value between CAN box unit connector C-15 terminal 1 and ground.

      OK: The resistance should be 2 ohms or less. 

      Fig 1: Measuring Resistance Value Between CAN Box Unit Connector C-15 Terminal 1 & Ground
      G07667316Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Is the measured resistance 2 ohms or less? 

    • YES:  Go to  Step 4.
    • NO:  Go to Step 3.
  3. STEP 3. Check the wiring harness between CAN box unit connector C-15 (terminal 1) and the ground. 
    • Check the ground wires for open circuit.
    NOTE: Also check intermediate connector C-108 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-108 is damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .

    Q: Is the wiring harness between CAN box unit connector C-15 (terminal 1) and the ground in good condition? 

    • YES:  Go to Step 4.
    • NO:  The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.
  4. STEP 4. Check the battery power supply circuit to the CAN box unit. Measure the voltage at CAN box unit connectors C-15. 
    1. Disconnect CAN box unit connectors C-15 measure the voltage available at the wiring harness side of the connector.
    2. Measure the voltage between CAN box unit connector C-15 terminal 2 and ground.

      OK: Battery positive voltage. 

      Fig 2: Measuring Voltage Between CAN Box Unit Connector C-15 Terminal 2 & Ground
      G07667317Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Is the measured voltage battery positive voltage? 

    • YES:  Go to  Step 6.
    • NO:  Go to Step 5.
  5. STEP 5. Check the wiring harness between CAN box unit connector C-15 (terminal 2) and fusible link (36). 
    • Check the power supply line for open circuit and short circuit.
    NOTE: Also check intermediate connector C-108 and ETACS-ECU connectors C-307 and C-317 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-108 or ETACS-ECU connector C-307 or C-317 is damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .

    Q: Is the wiring harness between CAN box unit connector C-15 (terminal 2) and fusible link (36) in good condition? 

    • YES:  Go to Step 6.
    • NO:  The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. The system should communicate with the CAN box unit normally.
  6. STEP 6. Using scan tool MB991958, check data list. 

    Check the input signal of ACC relay.

    • Turn the ignition switch to the ACC position.
      ACC SWITCH REFERENCE CHART

      Item No. Item name Normal conditions
      Item 288 ACC switch ON

      OK: Normal condition is displayed. 

    Q: Is the check result normal? 

  7. STEP 7. Check ETACS-ECU connector C-315 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

    Q: Is ETACS-ECU connector C-315 in good condition? 

  8. STEP 8. Check the battery power supply circuit to the CAN box unit. Measure the voltage at CAN box unit connectors C-15. 
    1. Disconnect CAN box unit connectors C-15 measure the voltage available at the wiring harness side of the connector.
    2. Measure the voltage between CAN box unit connector C-15 terminal 10 and ground.

      OK: Battery positive voltage. 

      Fig 3: Measuring Voltage Between CAN Box Unit Connector C-15 Terminal 10 & Ground
      G07667318Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Is the measured voltage battery positive voltage? 

    • YES:  Replace the CAN box unit.
    • NO:  Go to Step 9.
  9. STEP 9. Check the wiring harness between CAN box unit connectors C-15 (terminal 10) and ETACS-ECU connector C-315 (terminal 9). 
    • Check the power supply line for open circuit and short circuit.
    NOTE: Also check intermediate connector C-108 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-108 is damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .

    Q: Is the wiring harness between CAN box unit connectors C-15 (terminal 10) and ETACS-ECU connector C-315 (terminal 9) in good condition? 

    • YES:  No action is necessary and testing is complete.
    • NO:  The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. The system should communicate with the CAN box unit normally.
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