Patent ID: 6845312

Claim:
A method for determining the operational status of an internal combustion engine, comprising the steps of: providing a sensor which is configured to provide a signal which is representative of a physical event relating to said internal combustion engine; receiving a plurality of individual magnitudes of said signal which is associated with a plurality of occurrences of said physical event relating to said internal combustion engine; calculating an average magnitude of said plurality of individual magnitudes of said signal according to the equation A N =S N /N, where N is the number of individual magnitudes of said signal used in the calculation, S N is the running sum of the N individual magnitudes of said signal used in the calculation, and A N is the average magnitude of the individual magnitudes of said signal used in the calculation; amending the running sum upon the receipt of a new one of said plurality of individual magnitudes of said signal according to the equation S N =S N +M C −A P , where M C is the most recently received magnitude of said signal from said sensor and A P is the most recently calculated average prior to the receipt of M C ; and determining a threshold value as a function of the most recent value of A N .