•  The valve timing varies according to the driving conditions to improve engine output, fuel economy, and emission performance. High load range: advance (increases charging efficiency), Low load range: retard (reduces pumping loss), knocking/pre-ignition: retard (decreases temperature inside cylinder).

•  Electric VVT has been adopted to change the valve timing even when the engine is stopped so that the needs of both cold engine starts, which require a lot of air, and warm engine starts which require decreased temperature inside the cylinder to prevent pre-ignition are met.

•  Before installation, rotate the joint part at the end of the electric variable valve timing motor so that it is aligned to the joint groove on the electric variable valve timing actuator side.

•  The electric variable valve timing motor/driver can be assembled with the joint groove of the eccentric shaft at any position. (It does not cause vehicle damage or performance degradation.)

•  To examine, drive the vehicle (acceleration, deceleration, and at normal speed) and verify that the data monitor item VT_IN_ACT value changes in conjunction with the VT_IN_DES value.

•  Rotate the joint part of the electric variable valve timing motor to the left and right using the tips of your fingers and verify that it rotates smoothly in 15 degree increments.

•  After the engine is stopped, the valve timing is changed in preparation for the next engine start causing a gear engaging sound when the VVT (gear lowering device) operates. However, it does not indicate a malfunction.

•  Regarding the VVT operation after the engine is stopped, the valve timing is monitored while the PCM is activated, and if the valve timing deviates from the target value while the engine is stopped, it is returned to the target value.

•  The phase of the VVT is kept at the intermediate position while the engine is stopped by balancing the cam torque and motor torque, different from a hydraulic VVT which uses a lock pin to secure the phase. Therefore, if torque is input to the VVT while the engine is stopped, the torque balance is lost and the phase is deviated.