What is the purpose of the starter motor in a vehicle?

The starter motor is a critical component of a vehicle's starting system, and its primary purpose is to crank the engine to initiate the combustion process. When the ignition key is turned to the start position, electrical current is sent to the starter motor, which engages the flywheel and turns the engine over. This action allows the air-fuel mixture to be compressed within the cylinders, facilitating the engine's start.

Understanding the function of the starter motor helps clarify its role: without it, the engine could not reach the necessary RPMs for ignition to occur, leading to a failure to start the vehicle. This makes the starter motor essential for enabling the vehicle's operation, as it initiates the engine's performance cycle. The other options, while related to vehicle systems, do not accurately describe the function of the starter motor.