Conditions for Running the DTC

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

Battery voltage is at least 10.5 volts.
The engine coolant temperature (ECT) is at least 10°C (50°F).
Engine speed is more than 4,900 RPM.
The transmission is not in PARK or NEUTRAL.
DTC P2646 runs every time the enable criteria is met and the rocker arm oil control system is active.