A camshaft on a vehicle is a piece of technology that is responsible for controlling what does inside and comes out of a combustion chamber. It allows the fuel and air ratio to enter the combustion chamber and then afterwords releases the exhaust fumes. It consists of several radial cams, each of them displacing intake or exhaust valves. The camshaft is connected to another piece of technology called a crankshaft via a belt, chain, or gears. This allows the ECM to control the timings on when the valve needs to be opened and further the movement of the pistons.