Code No. P1020: Oil Feeder Control Valve System

OPERATION

Power is supplied to the oil feeder control valve connector terminal from the engine control relay connector terminal.
The engine-ECU connector terminal OCV makes the power transistor in the unit be in ON position, and that makes currents go on the oil feeder control valve connector terminal.

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-ECU.

TROUBLE JUDGEMENT

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.

Judgement Criterion

When the ECU command is "OPEN" and the valve position judged by the terminal voltage is "CLOSED".

or

When the ECU command is "CLOSED" and the valve position judged by the terminal voltage is "OPEN".

FAIL-SAFE AND BACKUP FUNCTION

The MIVEC control is prohibited.

PROBABLE CAUSES

Failed oil feeder control valve
Open/short circuit or harness damage in oil feeder control valve circuit or loose connector contact
Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Perform resistance measurement at oil feeder control valve connector.

Disconnect connector, and measure at control valve side.
Resistance between terminal.

OK: 6.9 - 7.9 Ω (at 20°C)

Q. Is the check result normal?

	Go to Step 2.

	Replace the oil feeder control valve.

STEP 2. Perform voltage measurement at oil feeder control 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 3.

	Repair or replace the connector, or check and repair harness between oil feeder control valve connector terminal and engine control relay connector terminal. Check power supply line open/short circuit

STEP 3. Perform voltage measurement at engine-ECU connector.

Disconnect connector, and measure at harness side.
Ignition switch: "ON"
Voltage between terminal OCV 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 oil feeder control valve connector terminal and engine-ECU connector terminal OCV. Check output line for open/short circuit.

STEP 4. Check harness in the OCV line between oil feeder control valve connector terminal and engine-ECU connector terminal.

Check output line for damage.

Q. Is the check result normal?

	Go to Step 5.

	Repair or replace the connector, or repair the damaged harness wire.

STEP 5. Check harness between oil feeder control valve connector terminal and engine control relay connector terminal.

Check power supply 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. 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 ).