Duty cycle monitoring system for an engine

A system for monitoring performance of an engine controlled by an engine control module, the engine control module operable to generate a plurality of sensor signals indicative of current performance of the engine, the system comprising:

• a monitoring device;
• a data link between said monitoring device and the engine control module to convey a plurality of sensor signals therebetween;
• a memory associated with said monitoring device;
• a micro-controller associated with said monitoring device and operable to;
• define an engine performance curve as a function of two or more engine operating parameters;
• define in said memory a plurality of sectors bounded by said performance curve, each sector corresponding to a range of values for said two or more engine operating parameters;
• over a predetermined number of iterations, read current values of selected ones of said plurality of sensor signals indicative of said two or more engine operating parameters;
• at each of said predetermined number of iterations, compare said current values to said range of values to determine a target sector of said plurality of sectors that said current data falls within;
• and
• at each of said predetermined number of iterations, update a duty cycle parameter stored in a location within said memory unique to said target sector, said duty cycle parameter different from said two or more engine operating parameters,
• whereby said duty cycle parameter for each of said plurality of sectors defines a duty cycle map for the engine, the duty cycle map indicative of cumulative engine operating time spent in each of said plurality of sectors.