P0019 code crankshaft and the bank 2 exhaust camshaft are out of sync. 

The Engine Control Module (ECM) controls the Oil Control Valve (OCV) to regulate the intake camshaft angle. As a result of the angle change, the engine timing is advance or retard. Optimizing engine timing will help the engine improve torque and fuel economy, and the exhaust emissions decrease under overall driving conditions. The Variable Valve Timing (VVT) system includes the Oil Control Valve (OCV) and VVT controller. The ECM detects the actual intake valve timing using signals from the camshaft and crankshaft position sensors, and performs feedback control.