Inspection Procedure 3: The Tachometer 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)

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? 

   YES  : Go to Step 2.

   NO  : Repair the CAN bus line (Refer to DIAGNOSIS ).

   Fig 1: Connecting Special Tool To Data Link Connector

   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 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.

3. STEP 3. Using scan tool MB991958, read the MFI diagnostic trouble code. 

   Check if DTC is set to the engine control module.

   Q: Is the DTC set? 

   YES  : Troubleshoot the MFI (Refer to DIAGNOSIS ).

   NO  : Go to Step 4.

4. STEP 4. Using scan tool MB991958, check data list. 
   1. Turn the ignition switch to the "ON" position.
   2. Check the data list on the combination meter.
      • Item 87: Tachometer
        • Should read engine speed.
   3. Turn the ignition switch to the "LOCK" (OFF) position.

   Q: Does it read engine speed? 

   YES  : Go to Step 5.

   NO  : Troubleshoot the MFI (Refer to DIAGNOSIS ). Complete the engine troubleshooting, and then go to  Step 6.

5. STEP 5. Using scan tool MB991958, check actuator test. 
   1. Turn the ignition switch to the "ON" position.
   2. Conduct the actuator test of the combination meter.
      • Item 2: Tachometer
        • The tachometer operates up to the set position.
   3. 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.

6. STEP 6. Retest the system 

   Check that the tachometer works normally.

   Q: Is the check result normal? 

   YES  : The procedure is complete.

   NO  : Go to  Step 1.