As the engine runs, combustion events occur thousands of times per minute; heat is a byproduct of engine operation. To prevent that heat from destroying the engine, a liquid cooling system is used. Beginning with the engine, the cooling system uses coolant passages inside the engine block, cylinder head, and possibly the intake manifold. These passages allow coolant to flow through these components to absorb heat. The engine coolant temperature sensor reads the temperature of the coolant in one or more of these passages, and relays that information to the vehicle computer. The computer will send another signal to the engine temperature gauge, and alert the driver if the temperature exceeds the specified range for that vehicle.