Inspection Procedure 4: Headlights Do Not Illuminate When The Passing Switch Is Operated: Diagnosis

Required Special Tools: 

• MB991223: Harness set
• 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. Check that the headlights operate. 

   Check that the low-beam and high-beam headlights illuminate normally.

   Q: Is the check result normal? 

   YES  : Go to Step 2.

   NO  : Refer to INSPECTION PROCEDURE 1 "ALL THE HEADLIGHTS (LOW-BEAM) DO NOT ILLUMINATE."  and INSPECTION PROCEDURE 2 "ALL THE HEADLIGHTS (HIGH-BEAM) DO NOT ILLUMINATE."  .

2. STEP 2. Using scan tool MB991958, read the ETACS-ECU diagnostic trouble code. 
   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 SCAN TOOL (M.U.T.-III)  ".
   2. Turn the ignition switch to the "ON" position.
   3. Check whether the ETACS-ECU related DTC is set.
   4. Turn the ignition switch to the "LOCK" (OFF) position.

   Q: Is the DTC set? 

   YES  : Diagnose the ETACS-ECU. Refer to DIAGNOSTIC TROUBLE CODE CHART .

   NO  : Go to Step 3.

   Fig 1: Connecting Special Tool To Data Link Connector

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
3. STEP 3. Retest the system 

   Q: Do the headlights (low-beam and high-beam) illuminate normally when turning ON the passing switch? 

   YES  : The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).

   NO  : Replace the ETACS-ECU.