Inspection Procedure 5: Audio illuminations does not work normally: Diagnosis

Required Special Tools: 

• MB991223: Harness Set
• MB992006: Extra Fine Probe

1. STEP 1. Operation check of the center panel unit 

   Operate the audio control switch of the center panel unit, and check if the audio operates normally.

   Q: Is the check result normal? 

   • YES:  Go to Step 2.
   • NO:  Refer to INSPECTION PROCEDURE 4 "THE AUDIO DOES NOT OPERATE NORMALLY BY OPERATING THE RADIO AND CD PLAYER OF THE CENTER PANEL UNIT."  .
2. STEP 2. Check the combination meter. 

   Check whether the combination meter works normally.

   Q: Is the check result normal? 

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

   Check again if the DTC is set to the combination meter.

   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  ".
   2. Turn the ignition switch to the "ON" position.
   3. Check for combination meter DTCs.
   4. Turn the ignition switch to the "LOCK" (OFF) position.

      Q: Is the DTC set? 

      • YES:  Diagnose the combination meter (Refer to DIAGNOSTIC TROUBLE CODE CHART ).
      • NO:  Go to Step 4.
        Fig 1: Connecting Special Tool To Data Link Connector

        Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
4. STEP 4. Check center panel unit connector C-18 and combination meter connector C-04 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Are center panel unit connector C-18 and combination meter connector C-04 in good condition? 

   • YES:  Go to Step 5.
   • NO:  Repair the connector concerned.
5. STEP 5. Check the wiring harness between center panel unit connector C-18 (terminal 16) and combination meter connector C-04 (terminal 23). 
   • Check the power supply line for open circuit and short circuit.
     NOTE: Also check A/C control panel connector C-120 <vehicle with A/C> or heater control panel C-136 <vehicle without A/C> for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If A/C control panel connector C-120 <vehicle with A/C> or heater control panel C-136 <vehicle without A/C> is damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .

     Q: Is the wiring harness between center panel unit connector C-18 (terminal 16) and combination meter connector C-04 (terminal 23) in good condition? 

     • YES:  Go to Step 6.
     • NO:  Repair the wiring harness.
6. STEP 6. Check A/C control panel C-120 <Vehicle with A/C> or heater control panel C-136 <vehicle without A/C> for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Is A/C control panel C-120 <Vehicle with A/C> or heater control panel C-136 <vehicle without A/C> in good condition? 

   • YES:  Go to Step 7.
   • NO:  Repair the connector concerned.
7. STEP 7. Check the wiring harness between A/C control panel C-120 (terminal 8) <Vehicle with A/C> or heater control panel C-136 (terminal 8) <vehicle without A/C> and combination meter connector C-04 (terminal 22). 
   • Check the wiring harness for open circuit and short circuit.

     Q: Is the wiring harness between A/C control panel C-120 (terminal 8) <Vehicle with A/C> or heater control panel C-136 (terminal 8) <vehicle without A/C> and combination meter connector C-04 (terminal 22) in good condition? 

     • YES:  Go to Step 8.
     • NO:  Repair the wiring harness.
8. STEP 8. Check the wiring harness between A/C control panel C-120 (terminal 10) <Vehicle with A/C> or heater control panel C-136 (terminal 10) <vehicle without A/C> and center panel unit connector C-18 (terminal 10). 
   • Check the wiring harness for open circuit and short circuit.

     Q: Is the wiring harness between A/C control panel C-120 (terminal 10) <Vehicle with A/C> or heater control panel C-136 (terminal 10) <vehicle without A/C> and center panel unit connector C-18 (terminal 10) in good condition? 

     • YES:  Go to Step 9.
     • NO:  Repair the wiring harness.
9. STEP 9. Check radio and CD player connector C-106 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Is radio and CD player connector C-106 in good condition? 

   • YES:  Go to Step 10.
   • NO:  Repair the connector concerned.
10. STEP 10. Check the wiring harness between center panel unit connector C-18 (terminal 4) and radio and CD player connector C-106 (terminal 9). 
    • Check the communication lines for open circuit and short circuit.

      Q: Is the wiring harness between center panel unit connector C-18 (terminal 4) and radio and CD player connector C-106 (terminal 9) in good condition? 

      • YES:  Go to Step 11.
      • NO:  Repair the wiring harness.
11. STEP 11. Replace the A/C control panel <vehicle with A/C> or heater control panel <vehicle without A/C> temporarily, and check the trouble symptom. 

    Replace the A/C control panel <vehicle with A/C> or heater control panel <vehicle without A/C> temporarily, and check that the audio illumination works normally.

    Q: Is the check result normal? 

    • YES:  Replace the A/C control panel <vehicle with A/C> or heater control panel <vehicle without A/C>.
    • NO:  Go to Step 12.
12. STEP 12. Replace the center panel unit temporarily, and check the trouble symptom. 

    Replace the center panel unit temporarily, and check that the audio illumination works normally.

    Q: Is the check result normal? 

    • YES:  Replace the center panel unit.
    • NO:  Replace the radio and CD player.