What are the reasons for normal engine shutdown?

[LeJasmine]

Reasons for normal engine shutdown: The car key is in the OFF position of the ignition switch. Normal engine shutdown is achieved by short-circuiting the spark plugs, as the engine operates by spark plug ignition. Turning the key to shut off the engine essentially shorts the high-voltage electricity supplied to the spark plugs, causing the engine to stop. Working principle of engine shutdown: 1. After the ignition is turned off, the ECU shuts down and no longer controls spark plug ignition or fuel injector operation; 2. When the ignition switch is in the ON position, the ECU powers on and supplies electricity to various sensors required for engine operation to prepare them for work. The fuel pump then operates for several seconds to build up oil pressure for normal fuel injection; 3. When the key is turned to the OFF position, it cuts power to the starter motor. At this point, the starter stops running, and the crankshaft ceases to drive the pistons in reciprocating motion, thereby achieving engine shutdown.