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 .

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.