US Patent 7908913 Solenoid diagnostic systems for cylinder deactivation control

A solenoid diagnostic system includes a pressure monitoring module that determines a first pressure in an intake cam phaser for an intake camshaft and a second pressure in an exhaust cam phaser for an exhaust camshaft associated with a cylinder. A fuel injection monitoring module determines a fuel injection status associated with the cylinder. A fault determination module diagnoses a fault in a solenoid associated with the cylinder based on the first pressure, the second pressure, and the fuel injection status.