Code No. P1021: Oil Feeder Control Valve System










OPERATION



  • Power is supplied to the oil feeder control valve (terminal No. 1) from the engine control relay (terminal No. 1).
  • The engine-A/T-ECU (terminal No. 95) makes the power transistor in the unit be in ON position, and that makes currents go on the oil feeder control valve (terminal No. 2).

FUNCTION



  • The oil feeder control valve switches the cams to operate the MIVEC in the low-speed or high-speed mode in accordance with the signals from the engine-A/T-ECU.

TROUBLE JUDGMENT


Check Conditions
  • Ignition switch is in "ON" position
  • Battery voltage is 10 - 16 V.
  • MIVEC operating in the low-speed mode.
Judgment Criterion
  • The engine-A/T-ECU terminal voltage of oil feeder control valve circuit is less than 1.5 V for 2 seconds.

PROBABLE CAUSES



  • Failed oil feeder control valve
  • Open/short circuit in oil feeder control valve circuit or loose connector contact
  • Failed engine-A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-101 oil feeder control valve connector

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

STEP 2. Perform resistance measurement at B-101 oil feeder control valve connector.

  • Disconnect connector, and measure at control valve side.
  • Resistance between terminal No. 1 and No. 2.
OK: 6.9 - 7.9 Ω (at 20°C)

Q. Is the check result normal?
Go to Step 3 .
Replace the oil feeder control valve.

STEP 3. Perform voltage measurement at B-101 oil feeder control valve connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 1 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 5 .
Go to Step 4 .

STEP 4. Connector check: B-15X engine control relay connector

Q. Is the check result normal?

    Check intermediate connector B-28, and repair if necessary. If intermediate connector is normal, check and repair harness between B-101 (terminal No. 1) oil feeder control valve connector and B-15X (terminal No. 1) engine control relay connector.

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

STEP 5. Perform voltage measurement at D-217 engine-A/T-ECU connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 95 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 7 .
Go to Step 6 .

STEP 6. Connector check: D-217 engine-A/T-ECU connector

Q. Is the check result normal?

    Check intermediate connector B-28, and repair if necessary. If intermediate connector is normal, check and repair harness between B-101 (terminal No. 2) oil feeder control valve connector and D-217 (terminal No. 95) engine-A/T-ECU connector.

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

STEP 7. Connector check: D-217 engine-A/T-ECU connector

Q. Is the check result normal?
Go to Step 8 .
Repair or replace the connector.

STEP 8. Check harness between B-101 (terminal No. 2) oil feeder control valve connector and D-217 (terminal No. 95) engine-A/T-ECU connector.
note Before checking harness, check intermediate connector B-28, and repair if necessary.

  • Check output line for damage.

Q. Is the check result normal?
Go to Step 9 .
Repair the damaged harness wire.

STEP 9. Connector check: B-15X engine control relay connector

Q. Is the check result normal?
Go to Step 10 .
Repair or replace the connector.

STEP 10. Check harness between B-101 (terminal No. 1) oil feeder control valve connector and B-15X (terminal No. 1) engine control relay connector.
note Before checking harness, check intermediate connector B-28, 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 diagnosis code

  • Reconfirmation of diagnosis code.

Q. Is the diagnosis code set?
Replace the engine-A/T-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).