What causes an automatic transmission car to suddenly not move when shifted into D gear?

[DelHenry]

Possible reasons include the parking brake not being released, a malfunctioning gear position sensor that fails to detect the current gear, insufficient transmission fluid level leading to ineffective power transfer, or the brakes not being released or being locked, preventing the vehicle from moving. Here are some related details: 1. Origin of electronic parking brakes: Electronic parking brakes were developed to address common issues such as locked brakes or incomplete release of the parking brake when starting the vehicle. 2. Advantages of electronic parking brakes: The primary advantage of electronic parking brakes is their simplicity—just pressing a button activates the parking brake function. Additionally, electronic parking brakes are designed with more user-friendly features and can be engaged under any circumstances. If accidentally pressed while driving, the electronic parking brake won't activate as long as the throttle is still engaged. During emergency braking, pressing the electronic parking brake won't lock the wheels but will instead provide enhanced braking force to assist in stopping. Electronic parking brakes are more convenient than traditional mechanical handbrakes.