What is the A-circle button in an automatic transmission?

[OKhloe]

The A-circle button in an automatic transmission refers to the Auto Hold system. The Auto Hold system (AUTOHOLD) is a technological application that enables automatic handbrake functionality while the vehicle is in operation. This technology allows drivers to avoid prolonged braking when the vehicle comes to a stop and prevents unnecessary rolling when the automatic electronic parking brake is engaged. Below is an introduction to the Auto Hold system: 1. Principle: The working principle of the Auto Hold system lies in the brake management system controlling the four-wheel brakes through the extended functionality of the electronic parking brake (EPB). In other words, the Auto Hold system is an extended feature of the electronic parking brake (EPB), controlled by the ESP component. 2. Operation Process: When the vehicle comes to a temporary stop and needs to restart within a short period, the parking function is managed by the ESP-controlled brakes. The computer uses a series of sensors to measure the vehicle's levelness and wheel torque, determining any tendency for the vehicle to roll, and applies an appropriate braking force to keep the vehicle stationary.