Inspection Procedure M-5: Column Switch: ETACS-Ecu Does Not Receive Any Signal From The Taillight Switch, The Headlight Switch, The Passing Light Switch, The Dimmer Switch Or The Turn-Signal Light Switch.: Diagnosis

Required Special Tools: 

• MB991223: Harness Set
• MB991958: Scan Tool (MUT-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (V.C.I.)
  • MB991827: MUT-III USB Cable
  • MB991911: MUT-III Main Harness B
• MB991813: SWS Monitor Kit
  • MB991806: SWS Monitor Cartridge
  • MB991812: SWS Monitor Harness (For Column-ECU)
  • MB991922: Probe Harness

1. STEP 1. Use scan tool MB991958 to select "ECU COMM CHK" on the SWS monitor display. 

   Check the column-ECU.

   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. Connect the DLC harness before connecting the column-ECU harness. Be sure to connect SWS monitor kit MB991813 after turning on scan tool MB991958.
   1. Connect scan tool MB991958 to the data link connector.
   2. Connect SWS monitor kit MB991813 to the column switch connector.
   3. Turn the ignition switch to the "LOCK" (OFF) position.
   4. Operate scan tool MB991958 according to the procedure below to display "ECU COMM CHK."
      1. Select "SYSTEM SELECT."
      2. Select "SWS."
      3. Select "SWS MONITOR."
      4. Select "ECU COMM CHK."
   5. Scan tool MB991958 should show "OK" on the "ECU COMM CHK" menu for the "COLUMN ECU" menu.

   Q: Is "OK" displayed on the "COLUMN ECU" menu? 

   • YES:  Go to Step 2.
   • NO:  Refer to "INSPECTION PROCEDURE A-2: COMMUNICATION WITH COLUMN SWITCH (COLUMN-ECU) IS NOT POSSIBLE ".
     Fig 1: Connecting Scan Tool MB991911 To Data Link Connector

     Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
     Fig 2: Identifying Column Switch Connector

     Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Replace the ECU. 
   1. Replace the column switch (turn-signal light and lighting switch).
   2. If the functions, which are described in "CIRCUIT OPERATION ", work normally, the input signal from the column switch (turn-signal light and lighting switch) should be normal.

   Q: Does the column switch (turn-signal light and lighting switch) send normal signal to the ECU? 

   • YES:  No action is necessary and testing is complete.
   • NO:  Replace the ETACS-ECU. If the functions, which are described in "CIRCUIT OPERATION ", work normally, the input signal from the column switch (turn-signal light and lighting switch) should be normal.