Idle stop and go system and method for controlling thereof

An idle-stop-and-go (ISG) system, comprising:

• an engine controller that stops an engine and transmits ISG stop signals to controllers when engine stop conditions for ISG are satisfied, and restarts the engine and transmits ISG restart signals to the controllers when engine restart conditions are satisfied;
• a motor-driven steering controller that allows for power steering even with the engine stopped, by keeping operation of a steering motor, when receiving the ISG stop signal from the engine controller;
• an automatic transmission controller that controls operation of an oil sub-pump of an automatic transmission to keep hydraulic pressure of the automatic transmission and transmits a shift range of the automatic transmission to the engine controller, when receiving the ISG stop signal from the engine controller;
• a brake controller that transmits operation of a brake pedal, brake boosting pressure, and vehicle traveling inclination angle to the engine controller;
• a cluster that shows the ISG operational status transmitted from the engine controller, and transmits signals for whether a hood is open, whether doors of the vehicle are open, and whether seat belts are not fastened to the engine controller;
• and
• a battery management system that transmits the charged status of a battery to the engine controller;
• wherein the engine controller controls the operation of the engine in accordance with whether the engine stop conditions and the engine restart conditions are satisfied, in response to the signals from the automatic transmission controller, the brake controller, the cluster, the battery management system, and sensors in the vehicle.