Code No. P2646: Valve Lift Control Motor Control Performance

OPERATION

Check code No. No.P2648: Valve lift control motor coil open (Refer to ).

FUNCTION

The engine-ECU monitors the variable valve lift operation.

TROUBLE JUDGMENT

Check Conditions

After 2 seconds since the ignition switch is turned ON or since the completion of engine start.
Battery positive voltage is more than 10 V and is less than 16.5 V.

JUDGEMENT CRITERIA

The difference between virtual control angle and target control angle exceeds the specified value for four seconds.

note Virtual control angle: The value which the valve lift ECU has calculated in accordance with the valve lift sensor output signal (the engine-ECU communicates via VLC-CAN).

note Target control angle: The value calculated according to operation status

FAIL-SAFE AND BACKUP FUNCTION

The valve lift is fixed to maximum. Otherwise, deenergises the motor.
V.V.T. phase angle is set to most retarded position.

PROBABLE CAUSES

Harness damage in valve lift control motor circuit or loose connector contact.
Failed valve lift control motor
Defective variable valve lift system
Failed valve lift ECU
Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

Q. Is any other diagnosis code than P2646 set?

	Inspection chart for diagnosis code (Refer to ).

	Go to Step 2.

STEP 2. Check valve lift control motor itself.

Valve lift control motor connector check.
Check valve lift control motor (Refer to ().

Q. Is the check result normal?

	Go to Step 3.

	Repair or replace the connector, or replace the valve lift control motor.

STEP 3. Check harness between valve lift control motor connector terminal and valve lift ECU connector terminal VLMV.

Check power supply line for damage.

Q. Is the check result normal?

	Go to Step 4.

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

STEP 4. Check harness between valve lift control motor connector terminal and valve lift ECU connector terminal VLMU.

Check power supply 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 valve lift control motor connector terminal and valve lift ECU connector terminal VLMW.

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. Variable valve lift mechanism check

Variable valve lift mechanism check (Refer to GROUP 11C - On-vehicle Service - Variable valve lift mechanism check).

Q. Is the check result normal?

	Go to Step 7.

	Repair

STEP 7. M.U.T.-III diagnosis code

Reconfirmation of diagnosis code.

Q. Is diagnosis code set?

	Go to Step 8.

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 8. Replace the valve lift ECU

After replacing the valve lift ECU, reconfirm whether the diagnosis code is set.

Q. Is the diagnosis code set?

	Replace the valve lift ECU.

	Check end.