Code No. P0047: Variable Geometry Control Solenoid Valve Circuit Low Input


OPERATION



  • Power is supplied to the variable geometry control solenoid valve connector terminal from the engine control relay connector terminal.
  • The engine-ECU connector terminal VGT makes the power transistor in the unit be in "ON" position, and that makes currents go on the variable geometry control solenoid valve connector terminal.

FUNCTION



  • The variable geometry control solenoid valve controls the vacuum pressure introduced into the variable geometry actuator, using the signal from the engine-ECU. This allows the boost pressure to be adequate for the driving conditions.

TROUBLE JUDGMENT


Check Conditions
  • Battery positive voltage is 8 - 16 V.
  • 2 seconds later after the engine has started up.
Judgment Criterion
  • Variable geometry control solenoid valve output voltage is 0.4 V or less (driving current is abnormally low).

FAIL-SAFE AND BACKUP FUNCTION



  • The fuel injection amount is restricted (Output restriction).
  • The open angle of the accelerator pedal is restricted.
  • The throttle valve is opened (Electrical discontinuity).
  • The EGR control is stopped (fully closed).
  • The DPF regeneration is prohibited.
  • The turbocharger control is prohibited.
  • The AS&G control is prohibited.

PROBABLE CAUSES



  • Failed variable geometry control solenoid valve
  • Open/short circuit or harness damage in variable geometry control solenoid valve circuit or loose connector contact
  • Failed engine-ECU

DIAGNOSIS PROCEDURE

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

  • Item 36: Variable geometry control solenoid valve
OK: The variable geometry actuator is operated

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Go to Step 2.

STEP 2. Perform resistance measurement at variable geometry control solenoid valve connector.

  • Disconnect connector, and measure at solenoid valve side.
  • Resistance between terminals.
OK: 10 - 14 Ω (at 20°C)

Q. Is the check result normal?
Go to Step 3.
Repair or replace the connector, or replace the variable geometry control solenoid valve.

STEP 3. Perform voltage measurement at variable geometry control solenoid valve connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal power supply line and body earth.
OK: System voltage

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

    Repair or replace the connector, or check and repair harness between variable geometry control solenoid valve connector terminal and engine control relay connector terminal.

    • Check power supply line open/short circuit

STEP 4. Perform voltage measurement at engine-ECU connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal VGT and body earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 5.

    Repair or replace the connector, or check and repair harness between variable geometry control solenoid valve connector terminal and engine-ECU connector terminal VGT.

    • Check output line for open/short circuit.

STEP 5. Check harness between variable geometry control solenoid valve connector terminal and engine-ECU connector terminal VGT.

  • Check output line for damage.

Q. Is the check result normal?
Go to Step 6.
Repair or replace the connector, or repair the damaged harness wire.

STEP 6. Check harness between variable geometry control solenoid valve connector terminal and engine control relay connector terminal.

  • Check power supply line for damage.

Q. Is the check result normal?
Go to Step 7.
Repair or replace the connector, or repair the damaged harness wire.

STEP 7. M.U.T.-III actuator test

  • Item 36: Variable geometry control solenoid valve
OK: The variable geometry actuator is operated

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Replace the engine-ECU.