A system for monitoring operation and diagnosing malfunctions in a variable valve actuation device is disclosed. The system has a rocker arm assembly that includes a first arm, a second arm with the first and second arms attached at a first end, a hydraulically operated latch assembly that functions to secure the first arm to the second arm when latched. The latch may be operated by a remote device. The rocker assembly pivots on a hydraulic lash adjuster (HLA). A control gallery connects the hydraulic valve to the latch. A pressure transducer is positioned either in the control gallery or the HLA and creates a signal indicating the sensed pressure. A reads the signal from the pressure transducer and identifies malfunctions of the rocker arm assembly. The system may also employ a non-contact transducer that monitors the state of the rocker arm assembly. The system may also employ a valve stem position sensor that monitors the engine valve position to determine malfunctions of the rocker arm assembly.