The Hella Diesel Glow Plug Controller - 008188471 is a device used in diesel engines to control the operation of the glow plugs. Glow plugs are essential for starting diesel engines, especially in cold weather, as they heat up the air inside the engine to facilitate combustion. The controller is responsible for sending the correct amount of power to the glow plugs, ensuring they reach the necessary temperature for the engine to start. This controller is specifically designed for diesel engines and is manufactured by Hella, a leading automotive parts supplier. It is a crucial component in the starting process of diesel engines and helps to improve engine performance and reliability.