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 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. 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 10 .

	Repair the damaged harness wire.

STEP 10. 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 ).