An engine has a lubrication system configured to lubricate at least a portion of the engine with lubricant. Defect detection includes detecting open circuits in one or more of the transmission lines, detecting short circuits between one or more of the transmission lines and a power supply, detecting short circuits between the transmission lines, or detecting short circuits across optional AC-couplings in the transmission lines. A second reference position moving relative to the first reference position during positioning movement of the drive member is spatially configured adjacent a first outer surface of the spring body.