Inspection Procedure 7: The headlight automatic shutdown function does not work normally: 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 (Vehicles with CAN communication system)

1. STEP 1. Using scan tool MB991958, Check the configuration function. 

   Use the ETACS-ECU configuration function to check that the "Head light auto cut customize" is set to "Enable (C-spec.)"

   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. Refer to "HOW TO CONNECT THE SCAN TOOL (M.U.T.-III)  ."
   2. Turn the ignition switch to the "ON" position.
   3. Use the ETACS-ECU configuration function to check that the "Headlight auto cut customize" is set to "C-spec."
   4. Turn the ignition switch to the "LOCK" (OFF) position.

   Q: Is the check result normal? 

   1. YES:  Go to Step 2.
   2. NO:  Use the ETACS-ECU configuration function to set the "Headlight auto cut customize" to "Enable (C-spec.)" (Refer to CUSTOMIZATION FUNCTION  ).
      Fig 1: Identifying Special Tools

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Using scan tool MB991958, read the diagnostic trouble code. 
   1. Turn the ignition switch to the "ON" position.
   2. Check whether the ETACS-ECU related DTC is set.
   3. Turn the ignition switch to the "LOCK" (OFF) position.

   Q: Is the DTC set? 

   1. YES:  Diagnose the ETACS-ECU (Refer to DIAGNOSIS ).
   2. NO:  Go to Step 3.
3. STEP 3. Using scan tool MB991958, check data list. 

   Use the ETACS-ECU service data to check the signals related to the operation of headlight automatic shutdown function.

   • Turn the ignition switch to the LOCK (OFF) position.
   • Illuminate the headlights.

     Item No.	Item name	Normal condition
     Item 206	Head light LO ON duty	100%
     Item 254	IG voltage	1 V or less

   • Open the driver's door.

     Item No.	Item name	Normal condition
     Item 256	Dr door ajar switch	Open

   Q: Does scan tool MB991958 display the items "Head light LO ON duty", "IG voltage" and "Dr door ajar switch" as normal condition? 

   1. YES:  Go to Step 4.
   2. NO:  Troubleshoot the ETACS-ECU. Refer to DIAGNOSIS .
4. STEP 4. Retest the system 

   Check that the headlight automatic shutdown function works normally.

   Q: Is the check result normal? 

   1. YES:  The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
   2. NO:  Replace the ETACS-ECU.