DIAGNOSTIC ITEM 12: Diagnose when the scan tool cannot receive the data sent by ECM: Diagnosis

Required Special Tools: 

• MB991223: Harness Set
• MB992006: Extra Fine Probe

1. STEP 1. Check joint connector (CAN3) C-124 <except RALLIART>, joint connector (CAN4) A-55 <RALLIART>, ECM connector B-109 and intermediate connector A-54 <RALLIART> 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 joint connector (CAN3) C-124 <except RALLIART>, joint connector (CAN4) A-55 <RALLIART>, ECM connector B-109 and intermediate connector A-54 <RALLIART> in good condition? 

   1. YES:  Go to Step 2.
   2. NO:  Repair the damaged parts.
2. STEP 2. Check the wiring harness between joint connector (CAN3) C-124 <except RALLIART> or joint connector (CAN4) A-55 <RALLIART> and ECM connector B-109. 
   CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to SERVICE PRECAUTIONS  .
   1. Disconnect joint connector (CAN3) C-124 <except RALLIART> or joint connector (CAN4) A-55 <RALLIART> and ECM connector B-109, and check the wiring harness.
   2. Check the wiring harness between joint connector (CAN3) C-124 (terminal 4) and ECM connector B-109 (terminal 90) <except RALLIART>

      OK: Continuity exists (2 Ω or less) 

      Fig 1: Checking Wiring Harness Between Joint Connector C-124 And ECM Connector B-109

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
   3. Check the wiring harness between joint connector (CAN3) C-124 (terminal 15) and ECM connector B-109 (terminal 91) <except RALLIART>

      OK: Continuity exists (2 Ω or less) 

      Fig 2: Checking Wiring Harness Between Joint Connector C-124 (Terminal 15) And ECM Connector B-109

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
   4. Check the wiring harness between joint connector (CAN4) A-55 (terminal 6) and ECM connector B-109 (terminal 90) <RALLIART>

      OK: Continuity exists (2 Ω or less) 

      Fig 3: Checking Wiring Harness Between Joint Connector A-55 And ECM Connector B-109

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
   5. Check the wiring harness between joint connector (CAN4) A-55 (terminal 19) and ECM connector B-109 (terminal 91) <RALLIART>

      OK: Continuity exists (2 Ω or less) 

      Q: Is the wiring harness between joint connector (CAN3) C-124 <except RALLIART> or joint connector (CAN4) A-55 <RALLIART> and ECM connector B-109 in good condition? 

      1. YES:  Check the power supply circuit of the ECM. Refer to TROUBLESHOOTING <2000-PETROL (except RALLIART)>, TROUBLESHOOTING <RALLIART> or TROUBLESHOOTING <2400>.
      2. NO:  Repair the wiring harness between joint connector (CAN3) C-124 <except RALLIART> or joint connector (CAN4) A-55 <RALLIART> and ECM connector B-109.
         Fig 4: Checking Wiring Harness Between Joint Connector A-55 And ECM Connector B-109

         Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.