Why does an automatic transmission car suddenly slow down during normal driving?

[GrahamAnn]

It could be due to a slipping torque converter or internal transmission clutches and brakes. Additional Information: Automatic Transmission: As the name suggests, it eliminates the need for the driver to manually shift gears. The vehicle automatically selects the appropriate gear based on driving speed and traffic conditions. A typical automatic transmission car has six gear positions, arranged from top to bottom as: P, R, N, D, S, L. Automatic Transmission Cars: Automatic transmission cars typically use hydraulic transmission devices to replace the mechanical clutch of manual transmission cars, hence there is no clutch pedal. When the engine speed is low, the torque transmitted by the fluid is limited and insufficient to propel the car forward. When the gear lever is placed in the drive position and the brake pedal is released, as the accelerator is pressed and engine speed increases, the transmitted torque increases, pushing the car forward.