Why does the engine fault light reset after power failure?

[SanEmersyn]

The engine control unit determines the engine fault to be temporary. Low internal temperature during winter startup: During cold starts in winter, insufficient gasoline atomization in the cylinders may trigger the fault light. As the engine warms up and temperature rises, the fault naturally resolves and the light turns off. Presence of engine faults: The engine fault signal is issued by the engine control unit. After the vehicle is turned off and power is disconnected, the engine control unit reboots and performs self-diagnostics again. If no issues affecting normal operation are detected, the fault light will turn off. When faults are detected, a yellow or red warning light will illuminate.