Inspection Procedure 4: Tone alarm does not sound 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, 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. Refer to "HOW TO CONNECT THE SCAN TOOL (M.U.T.-III)  ."
   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: Scan Tool And Laptop Connection

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Using scan tool MB991958, read the combination meter diagnostic trouble code. 

   Check if DTC is stored in the combination meter.

   Q: Is the DTC stored? 

   1. YES:  Troubleshoot the combination meter (Refer to DIAGNOSTIC TROUBLE CODE CHART  ).
   2. NO:  Go to Step 3.
3. STEP 3. Using scan tool MB991958, read for any diagnostic trouble code. 

   Check if diagnostic trouble code is stored in the CVT, TC-SST, ETACS-ECU, WCM, KOS-ECU, audio and A/C-ECU < vehicles with A/C > or heater control unit < vehicles without A/C >.

   Q: Is the DTC stored in the any of the above? 

   1. YES < Stored in the CVT. >:  Troubleshoot the CVT (Refer to DIAGNOSTIC TROUBLE CODE CHART ).
   2. YES < Stored in the TC-SST. >:  Troubleshoot the TC-SST (Refer to DIAGNOSTIC TROUBLE CODE CHART ).
   3. YES < Stored in the ETACS. >:  Troubleshoot the ETACS (Refer to DIAGNOSTIC TROUBLE CODE CHART ).
   4. YES < Stored in the WCM. >:  Troubleshoot the WCM (Refer to DIAGNOSTIC TROUBLE CODE CHART ).
   5. YES < Stored in the KOS. >:  Troubleshoot the KOS (Refer to DIAGNOSTIC TROUBLE CODE CHART ).
   6. YES < Stored in the A/C/Heater control unit. >:  Troubleshoot the A/C/Heater control unit (Refer to Manual A/C DIAGNOSTIC TROUBLE CODE CHART or Automatic A/C DIAGNOSTIC TROUBLE CODE CHART ).
   7. NO:  Go to Step 4.
4. STEP 4. Check by scan tool MB991958 "Special Function" 

   Using scan tool MB991958, select "Test" from the special function of the combination meter. Execute the following item to check the tone alarm.

   • Item 3: Buzzer (AUTO)

   Q: Is the check result normal? 

   1. YES:  Go to Step 5.
   2. NO:  Replace the combination meter.
5. STEP 5. Retest the system 

   Check that the tone alarm sounds 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 combination meter.