Patent ID: 7877188

Claim:
A control system for an internal combustion engine, comprising: a fuel amount detector for detecting a remaining fuel amount in a fuel tank; a smoothing calculation portion that calculates a smooth output value, which is obtained by smoothing an output value of the fuel amount detector in a temporal direction, when a vehicle speed is in a lower speed region than a predetermined speed; a continuous low speed condition detection portion that detects a continuous low speed condition in which the vehicle speed remains in the low speed region continuously beyond a predetermined time period; a calculation processing portion that successively calculates a maximum value and a minimum value of the smooth output value throughout the continuous low speed condition from an engine start-up to an engine stoppage; a reference setting portion that updates and stores a reference value in response to the engine stoppage and in accordance with the current minimum value calculated by the calculation processing portion; and a fuel supply determination portion that detects a fuel supply to the fuel tank during the continuous low speed condition on the basis of a comparison between the maximum value calculated by the calculation processing portion and the reference value stored by the reference setting portion.