DTC B2101: IG SW Start POS. Circuit Low; DTC B2102: IG SW Start POS. Circuit High: Diagnosis

Required Special Tools: 

• 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

1. STEP 1. Using scan tool MB991958, diagnose the CAN bus line. 
   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. Connect scan tool MB991958 to the data link connector.
   2. Turn the ignition switch to the "ON" position.
   3. Diagnose the CAN bus line.
   4. Turn the ignition switch to the "LOCK" (OFF) position.

      Q: Is the CAN bus line found to be normal? 

      1. YES:  Go to Step 2.
      2. NO:  Repair the CAN bus line (Refer to DIAGNOSIS ).
         Fig 1: Connecting Scan Tool To Data Link Connector

         Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Check ETACS-ECU connector C-317 and WCM connector C-07 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Is ETACS-ECU connector C-317 and WCM connector C-07 in good condition? 

   1. YES:  Go to Step 3.
   2. NO:  Repair the defective connector.
3. STEP 3. Check the wiring harness between WCM connector C-07 (terminal No. 9) and the ETACS-ECU connector C-317 (terminal No. 5) for open circuit. 
   1. Disconnect WCM connector C-07 and ETACS-ECU connector C-317, and check the wiring harness.
   2. Check the wiring harness between WCM connector C-07 (terminal No. 9) and ETACS-ECU connector C-317 (terminal No. 5)

      OK: Continuity exists (2 Ω or less) 

      NOTE: Also check joint connector (1) C-101 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector (1) C-101 is damaged, repair or replace the damaged component(s) as described in HARNESS CONNECTOR INSPECTION .

      Q: Is the wiring harness between WCM connector C-07 (terminal No. 9) and the ETACS-ECU connector C-317 (terminal No. 5) in good condition? 

      1. YES:  Go to Step 4.
      2. NO:  Repair the wiring harness between WCM connector C-07 (terminal No. 9) and ETACS-ECU connector C-317 (terminal No. 5).
         Fig 2: Checking Wiring Harness Between WCM Connector C-07 And ETACS-ECU Connector C-317

         Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
4. STEP 4. Using scan tool MB991958, check data list. 

   Use the ETACS-ECU data list to check the signals related to the ignition voltage.

   1. Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
      ITEM REFERENCE
      
      

      Item No.	Item name	Normal condition
      Item 254	IG voltage	Battery positive voltage

      Q: Does scan tool MB991958 display the item "IG voltage" as normal condition? 

      1. YES:  Go to Step 5.
      2. NO:  Diagnose the ETACS-ECU (Refer to DIAGNOSIS ).
5. STEP 5. Recheck for diagnostic trouble code. 

   Check again if the DTC is set to the WCM.

   1. Erase the DTC.
   2. Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
   3. Check if DTC is set.
   4. Turn the ignition switch to the "LOCK" (OFF) position.

      Q: Is the DTC set? 

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