A method for diagnosing the performance of a refueling event detection system for a vehicle is provided. The method includes the steps of a) determining a fuel change amount based on a difference of an indicated fuel amount and a previously indicated fuel amount, b) determining a consumed amount of fuel consumed by the engine since a prior refueling event was detected, and c) diagnosing the performance of the refueling event detection system based on the consumed amount and the fuel change amount.