Faults reported in Toyota’s Prius have not been established by technicians from the National Highway Traffic Safety Administration.

An over-accelerating runaway Prius, reported by a driver in California last week, resulted in a two-day inspection, in which officials said the drive power of the Prius should have shut down during a circumstance when both the accelerator and the brake were fully engaged.

While the driver, James Sikes, 61, says he reached uncontrollable speeds on a California highway when his Toyota Prius underwent sudden acceleration, a technical report has stated the over-speed phenomenon should not have been possible, either electronically or mechanically, as Sikes had engaged both the brake and accelerator at the same time.