LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mitsubishi >> 2005 >> Galant LS >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Communication Devices >> Controller Area Network (Can) >> Diagnosis >> Can Bus Diagnostics >> DIAGNOSTIC ITEM 18: Diagnose The Lines Between CAN Main Bus Line And The Powertrain Control Module < Vehicles With ABS > >> Diagnosis
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DIAGNOSTIC ITEM 18: Diagnose The Lines Between CAN Main Bus Line And The Powertrain Control Module < Vehicles With ABS >: Diagnosis

Required Special Tools: 

  1. STEP 1. Check ABS-ECU connector A-02 and powertrain control module connector B-19 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 
    CAUTION: The strand end of the twisted wire should be within 10 cm (4 inches) from the connector. For details, refer to SERVICE PRECAUTIONS .

    Q: Are ABS-ECU connector A-02 and powertrain control module connector B-19 in good condition? 

    1. YES:  Go to Step 2.
    2. NO:  Repair the damaged parts.
      Fig 1: Identifying ABS-ECU Connector A-02
      G02378132Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
      Fig 2: Identifying Powertrain Control Module Connector B-19
      G02378133Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  2. STEP 2. Check the CAN bus lines between the ABS-ECU and the powertrain control module. Measure the resistance between ABS-ECU connector A-02 and powertrain control module connector B-19. 
    CAUTION: A digital multimeter should be used. For details, refer to SERVICE PRECAUTIONS .
    CAUTION: The test wiring harness should be used. For details, refer to SERVICE PRECAUTIONS .
    1. Disconnect ABS-ECU connector A-02 and powertrain control module connector B-19, and measure the resistance between each wiring harness side connector.
    2. Turn the ignition switch to the "LOCK" (OFF) position.
      CAUTION: Disconnect the negative battery terminal. For details, refer to SERVICE PRECAUTIONS .
    3. Disconnect the negative battery terminal.
      Fig 3: Identifying ABS-ECU Connector A-02
      G02378134Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
      Fig 4: Identifying Powertrain Control Module Connector B-19
      G02378135Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    4. Measure the resistance between ABS-ECU connector terminal 23 and powertrain control module connector terminal 18.

      OK: 2 ohms or less 

      Fig 5: Measuring Resistance Between ABS-ECU Connector Terminal 23 And Powertrain Control Module Connector Terminal 18
      G02378136Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    5. Measure the resistance between ABS-ECU connector terminal 24 and powertrain control module connector terminal 17.

      OK: 2 ohms or less 

      CAUTION: Strictly observe the specified wiring harness repair procedure. For details, refer to PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES .
      Fig 6: Measuring Resistance Between ABS-ECU Connector Terminal 24 And Powertrain Control Module Connector Terminal 17
      G02378137Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Do all the resistances measure 2 ohms or less? 

    1. YES:  If all the resistances measure 2 ohms or less, go to Step 3.
    2. NO:  If either of the resistances measures more than 2 ohms or all the resistances measure more than 2 ohms, repair the wiring harness between ABS-ECU connector and the powertrain control module connector.
    3. Measure the resistance between ABS-ECU connector terminal 24 and powertrain control module connector terminal 17
  3. STEP 3. Check the CAN bus lines inside the ABS-ECU. Measure the resistance at ABS-ECU connector A-02. 
    CAUTION: A digital multimeter should be used. For details, refer to SERVICE PRECAUTIONS .
    CAUTION: The test wiring harness should be used. For details, refer to SERVICE PRECAUTIONS .
    1. Disconnect ABS-ECU connector A-02, and measure the resistance at the component side of ABS-ECU connector A-02.
    2. Turn the ignition switch to the "LOCK" (OFF) position.
      CAUTION: Disconnect the negative battery terminal. For details, refer to SERVICE PRECAUTIONS .
    3. Disconnect the negative battery terminal.
      Fig 7: Identifying ABS-ECU Connector A-02
      G02378138Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    4. Measure the resistance between ABS-ECU connector terminals 7 and 23.

      OK: 2 ohms or less 

      Fig 8: Measuring Resistance Between ABS-ECU Connector Terminals 7 And 23
      G02378139Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    5. Measure the resistance between ABS-ECU connector terminals 24 and 25.

      OK: 2 ohms or less 

      CAUTION: Strictly observe the specified wiring harness repair procedure. For details, refer to PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES .
      Fig 9: Measuring Resistance Between ABS-ECU Connector Terminals 24 And 25
      G02378140Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    Q: Do all the resistances measure 2 ohms or less? 

    1. YES:  If all the resistances measure 2 ohms or less, power supply to the powertrain control module may be suspected. Diagnose the engine. Refer to INSPECTION PROCEDURE 2: SCAN TOOL COMMUNICATION WITH PCM IS NOT POSSIBLE on < 2.4L Engine > or INSPECTION PROCEDURE 2: SCAN TOOL COMMUNICATION WITH PCM IS NOT POSSIBLE on < 3.8L ENGINE >.
    2. NO:  If either of the resistances measures more than 2 ohms or all the resistances measure more than 2 ohms, replace the ABS-ECU.
scientia non olet · About LEMON Manuals