As engine life decreases, it no longer provides the combustion pressure required to start the engine. Cold air is denser. For this reason, it starts when the engine is cold. However, when the engine is hot, the density of the air is low. The engine requires more RPM to start. Engine will be does not start easily and requires more cranking. This will drain the battery and damage the starter motor. With this module, the engine RPM required to start is adjusted, allowing the engine to start and solving the problem.