malfunction indicator light and the engine controller may then take the appropriate failure mode actions to protect the base engine hardware such as limiting the engine speed precise determination of which cylinder or which vva device is malfunctioning may be done by other related vva diagnostic algorithms utilizing the existing engine sensor set typically included in the engine management system as well as dealer service bay diagnostic tools a second level of diagnosability is the detection of when in the crank angle domain the rf signal is occurring and performing a simple calculation to determine its relative position to the engine 39 s firing order this would permit the diagnostics algorithm to set a different malfunction code for each engine cylinder the malfunction is associated with the final determination of exactly which two mode vva lost motion device is malfunctioning may be left for the dealer service bay a third level of diagnosability is applicable for engines having two or more u201c two mode u201d intake valves or exhaust valves per cylinder by using distinctively different geometry piezo electric elements in the lost motion devices within a cylinder a first lost motion device may be constructed to broadcast a signal characteristic such as signal frequency that is distinctively different from a signal characteristic broadcasted by a second lost motion device within that same cylinder thus the rf radio receiver may be made to provide different output signals to distinguish between first and second lost motion devices within a single cylinder this added level of discernment combined with the crank angle correlation of the rf signal events enables the diagnostic not only to determine which cylinder has the malfunctioning two mode vva lost motion device but also which device on which valve in that cylinder since camshaft bearing towers.