Code No. P0004: Suction Control Valve Battery Short


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 amount 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.

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

DIAGNOSTIC PROCEDURE

STEP 1. Connector check: B-07 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: B-10 engine-ECU connector.

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

STEP 4. Check harness between B-10 (terminal No. 131) engine-ECU connector and B-07 (terminal No. 1) suction control valve connector.
note Before checking harness, check intermediate connector A-16, and repair if necessary.

  • 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 B-10 (terminal No. 146) engine-ECU connector and B-07 (terminal No. 2) suction control valve connector.
note Before checking harness, check intermediate connector A-16, and repair if necessary.

  • 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.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).