Valve Timing Control System

Valve Timing Control System:

SYSTEM OPERATION
The valve timing control system is used to improve engine performance. The ECU will vary the intake valve opening and closing time based on engine temperature and speed, intake air volume, throttle position and gear position.

VTC Solenoid Operation:

The position (amount of advancement) of the intake cams are change by internal oil pressure acting upon a piston/servo in the timing belt pulley.

Valve Timing Control Solenoid:

SOLENOID VALVE
When the ECU senses the conditions necessary for increased engine performance in the low rpm band it energizes the solenoid. The solenoid extends, which in turn, closes off the bleed hole in the servo. This allows cam timing to advance, and the torque power band moves into a lower rpm range.

VTC Advancement Curve:

Valve Timing Operation:

Refer to the chart above for valve timing operation.