What was the ECM reprogram for ??
Due to software programming within the engine control unit, the operating threshold of the radiator fan used to cool the fuel temperature is not set low enough for the fan to operate at an appropriate temperature when using winter blend fuels. When North American winter fuel, which will vaporize at a lower temperature, is used, the fuel may begin to vaporize prematurely under certain outside temperature and low speed or stopped driving conditions. Premature vaporization causes a decrease in fuel pressure. If this occurs, the vehicle may experience a condition of rough idling, no‐start or engine stall. In some cases, if the engine were to stall, the driver may be unable to restart the vehicle for a certain period of time