Why does an automatic transmission car suddenly lose gear while driving?

[JacksonMarie]

Possible reasons include the parking lock mechanism being stuck and unable to reset, a faulty shift solenoid valve failing to execute gear shift commands, a damaged or broken gear shift cable, or a malfunction in the control computer. Below is an introduction to automatic transmission cars: 1. Introduction: 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 the engine speed increases, the transmitted torque also increases, pushing the car forward. 2. Parking method: After the car is parked, first press the brake and shift to N (Neutral), then engage the handbrake, release the foot brake and turn off the engine, and finally shift to P (Park) and remove the key. Instead of directly shifting into P, it is advisable for automatic transmission car owners to develop this parking habit to avoid lock-up, as it would be difficult to push the car alone otherwise.