Abstract: A method is presented for determining whether a fuel sensor in a vehicle having a fuel tank, a fuel delivery system, electronic engine controller, air flow and air/fuel ratio sensors and an instrument panel is stuck in-range. First, the electronic engine controller from the information provided by the above sensors estimates an amount of fuel consumed. The estimate is then compared to the actual fuel consumed data from the fuel sensor. If the difference between the actual and estimated amounts exceeds a small predetermined constant, the determination is made that the fuel sensor is stuck in-range and a diagnostic code is sent to the instrument panel and stored for use by a service technician.

Abstract: A system and method for resetting a portion of memory in a vehicle controller include repeatedly comparing data stored in at least one validation address with corresponding data stored in a non-volatile data storage device, transferring data representing nominal control parameter values from the non-volatile storage device to the portion of memory in response to a discrepancy between the data stored in the validation address and the corresponding data stored in the non-volatile data storage device, and modifying data stored in at least one validation address based on a request received via a communication port to generate discrepancy. A memory reset function is provided while limiting access by service technicians to modify values stored in memory and eliminating the need to disconnect the vehicle battery to remove power from the system. As such, other vehicle accessories are not affected by the reset function.