Code No. P0629: Suction Control Valve Battery Short <Except Euro5b>






OPERATION



  • The voltage is applied from the engine-ECU (terminal No. 131) to the suction control valve (terminal No. 1) via the power transistor in the engine-ECU.
  • The voltage is 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 rate is 4 mm3/st or more.
Judgment Criterion
  • When the driving duty ratio of the suction control valve is lower than the specified value, the driving current is higher than the specified value.

PROBABLE CAUSES



  • Failed suction control valve
  • Short circuit in suction control valve circuit or loose connector contact

  • Failed engine-ECU

DIAGNOSIS PROCEDURE


STEP 1. Connector check: A-47 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.

STEP 3. Connector check: C-103 engine-ECU connector



Q. Is the check result normal?

Go to Step 4.

Repair or replace the connector.

STEP 4. Check harness between C-103 (terminal No. 131) engine-ECU connector and A-47 (terminal No. 1) suction control valve connector.





  • Check power supply line for short circuit.

Q. Is the check result normal?

Go to Step 5.

Repair the damaged harness wire.

STEP 5. Check harness between C-103 (terminal No. 146) engine-ECU connector and A-47 (terminal No. 2) suction control valve connector.





  • Check earthing line for short circuit.

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 ).