Inspection Procedure 3: Abnormality in KOS-ECU power supply and ground circuits: Diagnosis

Required Special Tools: 

• MB992006: Extra fine probe
• MB991223: Harness set

1. STEP 1. Check KOS-ECU connector C-05 and ETACS-ECU connector C-317 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Is the KOS-ECU connector C-05 and ETACS-ECU connector C-317 in good condition? 

   1. YES:  Go to Step 2.
   2. NO:  Repair the defective connector.
2. STEP 2. Check the wiring harness between the KOS-ECU connector C-05 (terminal No. 38, 39) and the ETACS-ECU connector C-317 (terminal No. 10, 5) for open circuit. 
   1. Disconnect KOS-ECU connector C-05 and ETACS-ECU connector C-317, and check the wiring harness.
   2. Check the wiring harness between KOS-ECU connector C-05 (terminal No. 38) and ETACS-ECU connector C-317 (terminal No. 10)

      OK: Continuity exists (2 Ω or less) 

      Fig 1: Checking Wiring Harness Between KOS-ECU Connector C-05 And ETACS-ECU Connector C-317

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
   3. Check the wiring harness between KOS-ECU connector C-05 (terminal No. 39) and ETACS-ECU connector C-317 (terminal No. 5)

      OK: Continuity exists (2 Ω or less) 

      Q: Is the wiring harness between KOS-ECU connector C-05 (terminal No. 38, 39) and the ETACS-ECU connector C-317 (terminal No. 10, 5) in good condition? 

      1. YES:  Go to Step 3.
      2. NO:  Repair the wiring harness between KOS-ECU connector C-05 (terminal No. 38, 39) and the ETACS-ECU connector C-317 (terminal No. 10, 5).
         Fig 2: Checking Wiring Harness Between KOS-ECU Connector C-05 And ETACS-ECU Connector C-317

         Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
3. STEP 3. Check the wiring harness between the KOS-ECU connector C-05 (terminal No. 38, 39) and the ground for short circuit. 
   1. Disconnect KOS-ECU connector C-05, and check the wiring harness.
   2. Check the wiring harness between KOS-ECU connector C-05 (terminal No. 38) and ground

      OK: No continuity 

      Fig 3: Checking Wiring Harness Between KOS-ECU Connector C-05 (Terminal No. 38) And Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
   3. Check the wiring harness between KOS-ECU connector C-05 (terminal No. 39) and ground

      OK: No continuity 

      Q: Is the wiring harness between KOS-ECU connector C-05 (terminal No. 38, 39) and the ground in good condition? 

      1. YES:  Go to Step 4.
      2. NO:  Repair the wiring harness between KOS-ECU connector C-05 (terminal No. 38, 39) and the ground.
         Fig 4: Checking Wiring Harness Between KOS-ECU Connector C-05 And Ground

         Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
4. STEP 4. Check the wiring harness between the KOS-ECU connector C-05 and the ground for open circuit. 
   1. Disconnect KOS-ECU connector C-05, and check the wiring harness.
   2. Check the wiring harness between KOS-ECU connector C-05 (terminal No. 14) and ground.

      OK: Continuity exists (2 Ω or less) 

      Q: Is the wiring harness between KOS-ECU connector C-05 and the ground in good condition? 

      1. YES:  Go to Step 5.
      2. NO:  Repair the wiring harness between KOS-ECU connector C-07 and ground.
         Fig 5: Checking Wiring Harness Between KOS-ECU Connector C-05 (Terminal No. 14) And Ground

         Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
5. STEP 5. Retest the system 

   Q: Does the abnormality in KOS-ECU power supply and ground circuits in good condition? 

   1. YES:  The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
   2. NO:  Replace KOS-ECU and register the ID codes (Refer to ID CODES REGISTRATION JUDGMENT TABLE  ).