P0089 – Suction Control Valve Stuck MMC L200 IV


  • Battery power is supplied from the engine-ECU (terminal No. 131) to the suction control valve (terminal No. 1).
  • The engine-ECU (terminal No. 146) turns on the power transistor to flow current to the suction control valve (terminal No. 2).


  • The engine-ECU monitors the signals input from the rail pressure sensor.
  • The engine-ECU monitors the difference between the target fuel pressure and actual fuel pressure to check whether the suction control valve is open or fixed.


  • Battery positive voltage is 8 – 16 V
  • 2 seconds later after the ignition switch has been in “ON” position or the engine has started up
  • The actual rail pressure remains higher than the objective rail pressure by 10 MPa or more for a certain interval.


  • Failed suction control valve
  • Failed engine-ECU


    STEP 1. M.U.T.-III actuator test.

  • Item 19: Suction control valve
  • Q. Is the check result normal?

    STEP 2. Make a check on the following items.

  • Check for foreign matters (water, kerosene, etc.) in fuel and replace if necessary.
  • Check fuel filter itself.
  • Q. Are the check results normal?

    STEP 3. M.U.T.-III diagnosis code.

  • Reconfirmation of diagnosis code
  • Q. Is the diagnosis code set?

    STEP 4. Replace the suction control valve.

  • After learning the supply pump assembly, re-check the trouble symptoms
  • Q. Does trouble symptom persist?

    Author: admin