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)
- 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.
- Connect scan tool MB991958. Refer to "HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ".
- Turn the ignition switch to the "ON" position.
- Diagnose the CAN bus line.
- Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line (Refer to DIAGNOSIS ).
- STEP 2. Using scan tool MB991958, read the combination meter diagnostic trouble code.
Check if DTC is set to the combination meter.
Q: Is the DTC set?
YES : Troubleshoot the combination meter (Refer to DIAGNOSTIC TROUBLE CODE CHART ).
NO : Go to Step 3.
- STEP 3. Using scan tool MB991958, read for any diagnostic trouble code.
Check if diagnostic trouble code is set to the engine control module, TC-SST-ECU, ASC-ECU, ETACS-ECU, WCM, KOS-ECU, audio and A/C-ECU.
Q: Is the DTC set to the any of the above?
YES < Set to the engine control module. > : Troubleshoot the engine control module (Refer to DIAGNOSIS ).
YES < Set to the TC-SST-ECU. > : Troubleshoot the TC-SST (Refer to DIAGNOSIS ).
YES < Set to the ASC-ECU. > : Troubleshoot the ASC (Refer to DIAGNOSIS ).
YES < Set to the ETACS. > : Troubleshoot the ETACS (Refer to DIAGNOSTIC TROUBLE CODE CHART ).
YES < Set to the WCM. > : Troubleshoot the WCM (Refer to DIAGNOSIS ).
YES < Set to the KOS. > : Troubleshoot the KOS (Refer to DIAGNOSIS ).
YES < Set to the audio. > : Troubleshoot the audio (Refer to DIAGNOSTIC TROUBLE CODE PROCEDURES ).
YES < Set to the A/C. > : Troubleshoot the A/C (Refer to AUTO A/C DIAGNOSIS ).
NO < The diagnostic trouble code is not set. > : Go to Step 4.
- STEP 4. Using scan tool MB991958, check actuator test.
- Turn the ignition switch to the "ON" position.
- Conduct the actuator test of the combination meter.
- Item 12: Tone alarm
- The tone alarms sound normally.
- Item 12: Tone alarm
- Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result normal?
YES : Go to Step 5.
NO : Replace the combination meter.
- STEP 5. Retest the system
Check that the tone alarm normally.
Q: Is the check result normal?
YES : The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
NO : Replace the combination meter.