What Could Be the Reason for Suddenly Being Unable to Shift Gears in a Car?

[SanElliana]

It may be due to a malfunction inside the gear shift assembly preventing gear engagement; alternatively, there could be an issue with the control module inside the transmission. Below is relevant information: 1. Overview: A manual-automatic transmission is a gearbox that combines the functions of both manual and automatic shifting. This technology was developed to enhance the fuel efficiency and drivability of automatic transmissions, allowing the shift timing—normally determined by the computer—to be returned to the driver's control, thereby improving driving operability and enriching the driving experience. 2. Working Principle: Structurally, a manual-automatic transmission mainly consists of a conventional gearbox (similar to a manual transmission), an electronically controlled clutch, an automatic shift control mechanism, and an electronic control unit. The electronically controlled clutch automatically engages, disengages, or partially engages the clutch as needed. During operation, the transmission ECU controls a stepper motor to move the clutch fork, thereby engaging or disengaging the clutch.