System to diagnose variable valve actuation malfunctions by monitoring fluid pressure in a hydraulic lash adjuster gallery

Abstract

A system for 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 rocker arm assembly pivots upon a hydraulic lash adjuster. It also includes a source of pressurized fluid connected to a hydraulic valve that provided fluid high or low pressure fluid to the hydraulically-operated latch. The latch may be operated by a remote device. A pressure transducer is positioned within the hydraulic lash adjuster (HLA) and is adapted to create a signal indicating the fluid pressure in the HLA. A control unit is coupled to the hydraulic valve and the pressure transducer, and is adapted to sense engine operation parameters, actuate the hydraulic valve, read the signal from the pressure transducer and identify malfunctions of the rocker arm assembly based upon the signal from the transducer.

Dependencies are inferred from the claim text.