Code No. P0628: Suction Control Valve Open <Euro3, Euro4>








OPERATION



  • The current is applied from the engine-ECU (terminal No. 131) to the suction control valve (terminal No. 1) and earthed to the engine-ECU (terminal No. 146) from the suction control valve (terminal No. 2).

FUNCTION



  • The engine-ECU performs duty control over the suction control valve.
  • The engine-ECU checks whether the amount of current for driving duty is adequate.

TROUBLE JUDGMENT


Check Conditions
  • 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 supply pump and injector are being normally controlled.
  • The fuel injection amount is 4 mm3/st or more.
Judgment Criterion
  • When the driving duty ratio of the suction control valve is higher than the specified value, the driving current is lower than the specified value.

PROBABLE CAUSES



  • Failed suction control valve
  • Open circuit or harness damage in suction control valve circuit or loose connector contact
  • Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-129 suction control valve connector

Q. Is the check result normal?
Go to Step 2 .
Repair or replace the connector.

STEP 2. Check suction control valve itself.

  • Check suction control valve itself (Refer to ).

Q. Is the check result normal?
Go to Step 3 .
Replace the suction control valve. After replacing the suction control valve, learn the supply pump (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ).

STEP 3. Connector check: D-215 engine-ECU connector.

Q. Is the check result normal?
Go to Step 4 .
Repair or replace the connector.

STEP 4. Check harness between D-215 (terminal No. 131) engine-ECU connector and B-129 (terminal No. 1) suction control valve connector.

  • Check output line for open circuit.

Q. Is the check result normal?
Go to Step 5 .
Repair the damaged harness wire.

STEP 5. Check harness between D-215 (terminal No. 146) engine-ECU connector and B-129 (terminal No. 2) suction control valve connector.

  • Check earthing line for open circuit and damage.

Q. Is the check result normal?
Go to Step 6 .
Repair the damaged harness wire.

STEP 6. M.U.T.-III diagnosis code

  • Reconfirmation of diagnosis code.

Q. Is the diagnosis code set?
Replace the engine-ECU. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - Precautions Before Service - How to Perform Chassis Number Writing ). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ).
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).