In order for air to enter and exit the cylinders, a valve assembly must open and close in a synchronized manner, taking into account the position of the piston. To do this, the timing chain or belt is used, which causes the crankshaft to drive the camshafts to press the rocker arms. The rocker arms press the valves to open and allow the cylinder to enter or escape.
The swing arm control solenoid delivers hydraulic pressure to the variable timing mechanism. With this, the Variable Distribution System (VVT) can adjust the valve timing as needed. The Powertrain Control Module (PCM) uses the oil pressure switch on the swing arm to check that the oil pressure is right so that the VVT system is activated correctly. If the PCM does not detect the correct voltage signal on the switch, it will set the DTC code P2646 OBDII.