Code No. P0089: Suction Control Valve Stuck


FUNCTION



  • 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.

TROUBLE JUDGMENT


Check Conditions
  • Battery positive voltage is 8 - 16 V.
  • 2 seconds later after the engine has started up.
Judgment Criterion
  • The actual rail pressure remains higher than the objective rail pressure by 10 MPa or more for a certain interval.

FAIL-SAFE AND BACKUP FUNCTION



  • The rail pressure is controlled in the range between 50 and 100 MPa.
  • The fuel injection amount is restricted (Output restriction).
  • The open angle of the accelerator pedal is restricted.
  • The throttle valve is closed (Fixed opening degree).
  • The EGR control is stopped (fully closed).
  • The DPF regeneration is prohibited.
  • The AS&G control is prohibited.

PROBABLE CAUSES



  • Failed suction control valve
  • Failed fuel system
  • Failed fuel pressure regulator of fuel tank pump
  • Use of inappropriate fuel
  • Failed engine-ECU

DIAGNOSTIC PROCEDURE

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

  • Refer to Actuator Test Reference Table .

  1. Item 19: Suction control valve

Q. Is the check result normal?
Go to Step 2.
Go to Step 4.

STEP 2. Make a check on the following items.
note Foreign materials mixed in the suction control valve can possibly cause the stuck suction control valve. Check the followings.

  • Check it for the fuel conditions (mixed foreign materials, smell, colour or viscosity). If the fuel conditions are abnormal, replace the fuel.
  • Check fuel filter itself.

Q. Are the check results normal?
Go to Step 3.
Make a repair or replacement for items whose checking results are abnormal.

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

  • Reconfirmation of diagnosis code

Q. Is the diagnosis code set?
Go to Step 5.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 4. Replace the suction control valve.

  • Before replacing the suction control valve, check it for the fuel conditions (mixed foreign materials, smell, colour or viscosity). If the fuel conditions are abnormal, replace the fuel.
  • After the suction control valve, learn the supply pump (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns <4N1> ).
  • After learning the supply pump assembly, re-check the trouble symptoms.

Q. Does the trouble symptom persist?
Replace the engine-ECU.
The check is end.

STEP 5. Replace the fuel pump module assembly.

  • The fuel pressure regulator of the fuel tank pump can possibly be failed. Replace the fuel pump module assembly.
  • After replacing the fuel pump module assembly, re-check the trouble symptoms.

Q. Does the trouble symptom persist?
Replace the engine-ECU.
The check is end.