DIAGNOSTIC ITEM 4: Diagnose shorts in the ground to CAN-C bus line: Diagnosis

Required Special Tools: 

• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (V.C.I.)
  • MB991827: M.U.T.-III USB Cable
  • MB991910: M.U.T.-III Main Harness A
• MB992110: Power plant ECU check harness
• MB991997: ASC Check Harness

1. STEP 1. Check the wiring harness between joint connector (CAN2) C-104 and steering wheel sensor connector C-209 for a short to ground. Measure the resistance at joint connector (CAN2) C-104. 
   CAUTION: Disconnect the negative battery terminal. For details refer to SERVICE PRECAUTIONS  .
   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 joint connector (CAN2), and measure the resistance at the wiring harness side of joint connector (CAN2).
   2. Measure the resistance between joint connector (CAN2) terminal 7 and body ground.
      Fig 1: Measuring Resistance Between Joint Connector (CAN2) Terminal 7 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   3. Measure the resistance between joint connector (CAN2) terminal 20 and body ground.
      Fig 2: Measuring Resistance Between Joint Connector (CAN2) Terminal 20 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   Q: Do all the resistances measure 1 kilo ohm or more? 

   YES  : Go to Step 2.

   NO  : Go to Step  10.

2. STEP 2. Check the wiring harness between joint connector (CAN2) C-104 and S-AWC-ECU connector C-46 for a short to ground. Measure the resistance at joint connector (CAN2) C-104. 
   CAUTION: Disconnect the negative battery terminal. For details refer to SERVICE PRECAUTIONS  .
   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 joint connector (CAN2), and measure the resistance at the wiring harness side of joint connector (CAN2).
   2. Measure the resistance between joint connector (CAN2) terminal 5 and body ground.
      Fig 3: Measuring Resistance Between Joint Connector (CAN2) Terminal 5 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   3. Measure the resistance between joint connector (CAN2) terminal 16 and body ground.
      Fig 4: Measuring Resistance Between Joint Connector (CAN2) Terminal 16 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   Q: Do all the resistances measure 1 kilo ohm or more? 

   YES  : Go to Step 3.

   NO  : Go to Step  11.

3. STEP 3. Check the wiring harness between joint connector (CAN2) C-104 and ETACS-ECU connector C-301 for a short to ground. Measure the resistance at joint connector (CAN2) C-104. 
   CAUTION: Disconnect the negative battery terminal. For details refer to SERVICE PRECAUTIONS  .
   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 joint connector (CAN2), and measure the resistance at the wiring harness side of joint connector (CAN2).
   2. Measure the resistance between joint connector (CAN2) terminal 6 and body ground.
      Fig 5: Measuring Resistance Between Joint Connector (CAN2) Terminal 6 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   3. Measure the resistance between joint connector (CAN2) terminal 19 and body ground.
      Fig 6: Measuring Resistance Between Joint Connector (CAN2) Terminal 19 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   Q: Do all the resistances measure 1 kilo ohm or more? 

   YES  : Go to Step 4.

   NO  : Go to Step  12.

4. STEP 4. Check the wiring harness between joint connector (CAN3) C-127 and ASC-ECU connector A-05 for a short to ground. Measure the resistance at joint connector (CAN3) C-127. 
   CAUTION: Disconnect the negative battery terminal. For details refer to SERVICE PRECAUTIONS  .
   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 joint connector (CAN3), and measure the resistance at the wiring harness side of joint connector (CAN3).
   2. Measure the resistance between joint connector (CAN3) terminal 6 and body ground.
      Fig 7: Measuring Resistance Between Joint Connector (CAN3) Terminal 6 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   3. Measure the resistance between joint connector (CAN3) terminal 19 and body ground.
      Fig 8: Measuring Resistance Between Joint Connector (CAN3) Terminal 19 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   Q: Do all the resistances measure 1 kilo ohm or more? 

   YES < M/T >  : Go to Step 5.

   YES < TC-SST >  : Go to Step  6.

   NO  : Go to Step  13.

5. STEP 5. Check the wiring harness between joint connector (CAN3) C-127 and ECM connector B-10 < M/T > for a short to ground. Measure the resistance at joint connector (CAN3) C-127. 
   CAUTION: Disconnect the negative battery terminal. For details refer to SERVICE PRECAUTIONS  .
   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 joint connector (CAN3), and measure the resistance at the wiring harness side of joint connector (CAN3).
   2. Measure the resistance between joint connector (CAN3) terminal 4 and body ground.
      Fig 9: Measuring Resistance Between Joint Connector (CAN3) Terminal 4 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   3. Measure the resistance between joint connector (CAN3) terminal 15 and body ground.
      Fig 10: Measuring Resistance Between Joint Connector (CAN3) Terminal 15 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   Q: Do all the resistances measure 1 kilo ohm or more? 

   YES  : Check intermediate connector C-131, and repair if necessary. If the intermediate connector is in good condition, repair the wiring harness between joint connector (CAN2) C-104 and joint connector (CAN3) C-127.

   NO  : Go to Step  14.

6. STEP 6. Check the wiring harness between joint connector (CAN3) C-127 and shift lever connector C-27 < TC-SST > for a short to ground. Measure the resistance at joint connector (CAN3) C-127. 
   CAUTION: Disconnect the negative battery terminal. For details refer to SERVICE PRECAUTIONS  .
   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 joint connector (CAN3), and measure the resistance at the wiring harness side of joint connector (CAN3).
   2. Measure the resistance between joint connector (CAN3) terminal 7 and body ground.
      Fig 11: Measuring Resistance Between Joint Connector (CAN3) Terminal 7 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   3. Measure the resistance between joint connector (CAN3) terminal 20 and body ground.
      Fig 12: Measuring Resistance Between Joint Connector (CAN3) Terminal 20 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   Q: Do all the resistances measure 1 kilo ohm or more? 

   YES  : Go to Step 7.

   NO  : Go to Step  15.

7. STEP 7. Check the wiring harness between joint connector (CAN4) A-14 and ECM connector B-10 < TC-SST > for a short to ground. Measure the resistance at joint connector (CAN4) A-14. 
   CAUTION: Disconnect the negative battery terminal. For details refer to SERVICE PRECAUTIONS  .
   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 joint connector (CAN4), and measure the resistance at the wiring harness side of joint connector (CAN4).
   2. Measure the resistance between joint connector (CAN4) terminal 7 and body ground.
      Fig 13: Measuring Resistance Between Joint Connector (CAN4) Terminal 7 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   3. Measure the resistance between joint connector (CAN4) terminal 20 and body ground.
      Fig 14: Measuring Resistance Between Joint Connector (CAN4) Terminal 20 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   Q: Do all the resistances measure 1 kilo ohm or more? 

   YES  : Go to Step 8.

   NO  : Go to Step  14.

8. STEP 8. Check the wiring harness between joint connector (CAN4) A-14 and transaxle assembly connector B-107 < TC-SST > for a short to ground. Measure the resistance at joint connector (CAN4) A-14. 
   CAUTION: Disconnect the negative battery terminal. For details refer to SERVICE PRECAUTIONS  .
   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 joint connector (CAN4), and measure the resistance at the wiring harness side of joint connector (CAN4).
   2. Measure the resistance between joint connector (CAN4) terminal 6 and body ground.
      Fig 15: Measuring Resistance Between Joint Connector (CAN4) Terminal 6 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   3. Measure the resistance between joint connector (CAN4) terminal 19 and body ground.
      Fig 16: Measuring Resistance Between Joint Connector (CAN4) Terminal 19 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   Q: Do all the resistances measure 1 kilo ohm or more? 

   YES  : Go to Step 9.

   NO  : Go to Step  16.

9. STEP 9. Check the wiring harness between joint connector (CAN3) C-127 and joint connector (CAN2) C-104 for a short to ground. Measure the resistance at joint connector (CAN3) C-127. 
   CAUTION: Disconnect the negative battery terminal. For details refer to SERVICE PRECAUTIONS  .
   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 joint connector (CAN3), and measure the resistance at the wiring harness side of joint connector (CAN3).
   2. Measure the resistance between joint connector (CAN3) terminal 5 and body ground.
      Fig 17: Measuring Resistance Between Joint Connector (CAN3) Terminal 5 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   3. Measure the resistance between joint connector (CAN3) terminal 16 and body ground.
      Fig 18: Measuring Resistance Between Joint Connector (CAN3) Terminal 16 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

      OK: 1 kilo ohm or more 

   Q: Do all the resistances measure 1 kilo ohm or more? 

   YES  : Check intermediate connector A-13, and repair if necessary. If the intermediate connector is in good condition, repair the wiring harness between joint connector (CAN3) C-127 and joint connector (CAN4) A-14.

   NO  : Check intermediate connector C-131, and repair if necessary. If the intermediate connector is in good condition, repair the wiring harness between joint connector (CAN3) C-127 and joint connector (CAN2) C-104.

10. STEP 10. Using scan tool MB991958, diagnose the CAN bus line. (checking the steering wheel sensor for internal short to ground) 
    CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to SERVICE PRECAUTIONS  .
    CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
    1. Disconnect steering wheel sensor connector C-209.
    2. Connect scan tool MB991958 to the data link connector.
    Fig 19: Connecting Scan Tool To Data Link Connector
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. Turn the ignition switch to the "ON" position.
    4. Diagnose CAN bus lines, and check if the scan tool MB991958 screen is as shown in the figure.
       Fig 20: Checking Scan Tool Screen While Diagnose CAN Bus Lines (M/T)

       Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
       Fig 21: Checking Scan Tool Screen While Diagnose CAN Bus Lines (TC-SST)

       Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

       OK: The display of the scan tool MB991958 is as shown in the figure. 

    Q: Does scan tool MB991958 screen correspond to the illustration? 

    YES  : Repair the wiring harness between steering wheel sensor connector C-209 and joint connector (CAN2) C-104.

    NO  : Check steering wheel sensor connector C-209, and repair if necessary. If the steering wheel sensor connector is in good condition, replace the steering wheel sensor.

11. STEP 11. Using scan tool MB991958, diagnose the CAN bus line. (checking the S-AWC-ECU for internal short to ground) 
    CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to SERVICE PRECAUTIONS  .
    CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
    1. Disconnect S-AWC-ECU connector C-46.
    2. Connect scan tool MB991958 to the data link connector.
    Fig 22: Connecting Scan Tool To Data Link Connector
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. Turn the ignition switch to the "ON" position.
    4. Diagnose CAN bus lines, and check if the scan tool MB991958 screen is as shown in the figure.
       Fig 23: Checking Scan Tool Screen While Diagnose CAN Bus Lines (M/T)

       Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
       Fig 24: Checking Scan Tool Screen While Diagnose CAN Bus Lines (TC-SST)

       Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

       OK: The display of the scan tool MB991958 is as shown in the figure. 

    Q: Does scan tool MB991958 screen correspond to the illustration? 

    YES  : Repair the wiring harness between S-AWC-ECU connector C-46 and joint connector (CAN2) C-104.

    NO  : Check S-AWC-ECU connector C-46, and repair if necessary. If the S-AWC-ECU connector is in good condition, replace the S-AWC-ECU.

12. STEP 12. Check the wiring harness between joint connector (CAN2) C-104 and ETACS-ECU connector C-301 for a short to ground. 
    CAUTION: Disconnect the negative battery terminal. For details refer to SERVICE PRECAUTIONS  .
    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  .
    CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to SERVICE PRECAUTIONS  .
    1. Disconnect ETACS-ECU connector and joint connector (CAN2), and measure at the wiring harness side.
    2. Measure the resistance between joint connector (CAN2) terminal 6 and body ground.
       Fig 25: Measuring Resistance Between Joint Connector (CAN2) Terminal 6 And Body Ground

       Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

       OK: 1 kilo ohm or more 

    3. Measure the resistance between joint connector (CAN2) terminal 19 and body ground.
       Fig 26: Measuring Resistance Between Joint Connector (CAN2) Terminal 19 And Body Ground

       Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

       OK: 1 kilo ohm or more 

    Q: Do all the resistances measure 1 kilo ohm or more? 

    YES  : Check ETACS-ECU connector C-301, and repair if necessary. If the ETACS-ECU connector is in good condition, replace the ETACS-ECU.

    NO  : Repair the wiring harness between ETACS-ECU connector C-301 and joint connector (CAN2) C-104.

13. STEP 13. Using scan tool MB991958, diagnose the CAN bus line. (checking the ASC-ECU for internal short to ground) 
    CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to SERVICE PRECAUTIONS  .
    CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
    1. Disconnect ASC-ECU connector A-05.
    2. Connect scan tool MB991958 to the data link connector.
    Fig 27: Connecting Scan Tool To Data Link Connector
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. Turn the ignition switch to the "ON" position.
    4. Diagnose CAN bus lines, and check if the scan tool MB991958 screen is as shown in the figure.
       Fig 28: Checking Scan Tool Screen While Diagnose CAN Bus Lines (M/T)

       Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
       Fig 29: Checking Scan Tool Screen While Diagnose CAN Bus Lines (TC-SST)

       Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

       OK: The display of the scan tool MB991958 is as shown in the figure. 

    Q: Does scan tool MB991958 screen correspond to the illustration? 

    YES  : Repair the wiring harness between ASC-ECU connector A-05 and joint connector (CAN3) C-127.

    NO  : Check ASC-ECU connector A-05, and repair if necessary. If the ASC-ECU connector is in good condition, replace the ASC-ECU.

14. STEP 14. Using scan tool MB991958, diagnose the CAN bus line. (checking the ECM for internal short to ground) 
    CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to SERVICE PRECAUTIONS  .
    CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
    1. Disconnect ECM connector B-10.
    2. Connect scan tool MB991958 to the data link connector.
    Fig 30: Connecting Scan Tool To Data Link Connector
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. Turn the ignition switch to the "ON" position.
    4. Diagnose CAN bus lines, and check if the scan tool MB991958 screen is as shown in the figure.

       OK: The display of the scan tool MB991958 is as shown in the figure. 

    Q: Does scan tool MB991958 screen correspond to the illustration? 

    YES  : Repair the wiring harness between ECM connector B-10 and joint connector (CAN3) C-127 < M/T >, or check intermediate connector A-13, and repair if necessary. If the intermediate connector is in good condition, repair the wiring harness between ECM connector B-10 and joint connector (CAN4) A-14 < TC-SST >.

    Fig 31: Checking Scan Tool Screen While Diagnose CAN Bus Lines (M/T)

    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

    NO  : Check ECM connector B-10, and repair if necessary. If the ECM connector is in good condition, replace the ECM.

    Fig 32: Checking Scan Tool Screen While Diagnose CAN Bus Lines (TC-SST)

    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
15. STEP 15. Using scan tool MB991958, diagnose the CAN bus line. (checking the shift lever for internal short to ground) 
    CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to SERVICE PRECAUTIONS  .
    CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
    1. Disconnect shift lever connector C-27.
    2. Connect scan tool MB991958 to the data link connector.
    Fig 33: Connecting Scan Tool To Data Link Connector
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. Turn the ignition switch to the "ON" position.
    4. Diagnose CAN bus lines, and check if the scan tool MB991958 screen is as shown in the figure.
       Fig 34: Checking Scan Tool Screen While Diagnose CAN Bus Lines (M/T)

       Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
       Fig 35: Checking Scan Tool Screen While Diagnose CAN Bus Lines (TC-SST)

       Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

       OK: The display of the scan tool MB991958 is as shown in the figure. 

    Q: Does scan tool MB991958 screen correspond to the illustration? 

    YES  : Repair the wiring harness between shift lever connector C-27 and joint connector (CAN3) C-127.

    NO  : Check shift lever connector C-27, and repair if necessary. If the shift lever connector is in good condition, replace the shift lever.

16. STEP 16. Using scan tool MB991958, diagnose the CAN bus line. (checking the TC-SST-ECU for internal short to ground) 
    CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to SERVICE PRECAUTIONS  .
    CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
    1. Disconnect transaxle assembly connector B-107.
    2. Connect scan tool MB991958 to the data link connector.
    Fig 36: Connecting Scan Tool To Data Link Connector
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    3. Turn the ignition switch to the "ON" position.
    4. Diagnose CAN bus lines, and check if the scan tool MB991958 screen is as shown in the figure.
       Fig 37: Checking Scan Tool Screen While Diagnose CAN Bus Lines (M/T)

       Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
       Fig 38: Checking Scan Tool Screen While Diagnose CAN Bus Lines (TC-SST)

       Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

       OK: The display of the scan tool MB991958 is as shown in the figure. 

    Q: Does scan tool MB991958 screen correspond to the illustration? 

    YES  : Repair the wiring harness between transaxle assembly connector B-107 and joint connector (CAN4) A-14.

    NO  : Check transaxle assembly connector B-107, and repair if necessary. If the transaxle assembly connector is in good condition, replace the transaxle assembly.