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


OPERATION



  • Power is supplied to the variable geometry control solenoid valve (terminal No. 2) from the engine control relay (terminal No. 2).
  • The engine-ECU (terminal No. 17) makes the power transistor in the unit be in "ON" position, and that makes currents go on the variable geometry control solenoid valve (terminal No. 1).

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. Connector check: B-18 variable geometry control solenoid valve connector

Q. Is the check result normal?
Go to Step 3 .
Repair or replace the connector.

STEP 3. Perform resistance measurement at B-18 variable geometry control solenoid valve connector.

  • Disconnect connector, and measure at solenoid valve side.
  • Resistance between terminal No. 1 and No. 2.
OK: 10 - 14 Ω (at 20°C)

Q. Is the check result normal?
Go to Step 4 .
Replace the variable geometry control solenoid valve.

STEP 4. Perform voltage measurement at B-18 variable geometry control solenoid valve connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 2 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 6 .
Go to Step 5 .

STEP 5. Connector check: A-37X engine control relay connector

Q. Is the check result normal?

    Check intermediate connector A-17, and repair if necessary. If intermediate connector is normal, check and repair harness between B-18 (terminal No. 2) variable geometry control solenoid valve connector and A-37X (terminal No. 2) engine control relay connector.

    • Check power supply line open/short circuit
Repair or replace the connector.

STEP 6. Perform voltage measurement at B-09 engine-ECU connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 17 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 8 .
Go to Step 7 .

STEP 7. Connector check: B-09 engine-ECU connector

Q. Is the check result normal?

    Check and repair harness between B-18 (terminal No. 1) variable geometry control solenoid valve connector and B-09 (terminal No. 17) engine-ECU connector.

    • Check output line for open/short circuit.
Repair or replace the connector.

STEP 8. Connector check: B-09 engine-ECU connector

Q. Is the check result normal?
Go to Step 9 .
Repair or replace the connector.

STEP 9. Check harness between B-18 (terminal No. 1) variable geometry control solenoid valve connector and B-09 (terminal No. 17) engine-ECU connector.

  • Check output line for damage.

Q. Is the check result normal?
Go to Step 10 .
Repair the damaged harness wire.

STEP 10. Check harness between B-18 (terminal No. 2) variable geometry control solenoid valve connector and A-37X (terminal No. 2) engine control relay connector.
note Before checking harness, check intermediate connector A-17, and repair if necessary.

  • Check power supply line for damage.

Q. Is the check result normal?
Go to Step 11 .
Repair the damaged harness wire.

STEP 11. 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.