Inspection Procedure 2: The Speedometer Does Not Work (The Other Meters Work): Diagnosis
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicles 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 the ASC-ECU diagnostic trouble code.
Check if diagnostic trouble code is set to the ASC.
Q: Is the DTC set?
YES : Troubleshoot the ASC (Refer to DIAGNOSIS ).
NO : Go to Step 4.
- STEP 4. Using scan tool MB991958, check data list.
- Turn the ignition switch to the "ON" position.
- Check the data list on the combination meter.
- Item 80: Speedometer
- Should read vehicle speed.
- Item 80: Speedometer
- Turn the ignition switch to the "LOCK" (OFF) position.
Q: Does it read vehicle speed?
YES : Go to Step 5.
NO : Replace the combination meter.
- STEP 5. Using scan tool MB991958, check actuator test.
- Turn the ignition switch to the "ON" position.
- Conduct the actuator test of the combination meter.
- Item 1: Speedometer
- The speedometer operates up to the set position.
- Item 1: Speedometer
- Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result normally?
YES : Go to Step 6.
NO : Replace the combination meter.
- STEP 6. Retest the system.
Check that the speedometer works normally.
Q: Is the check result normal?
YES : The procedure is complete.
NO : Go to Step 1.