| 摘要 |
PURPOSE: A control method of an automatic transmission is provided to improve safety of the automatic transmission by automatically sensing a reverse state formed in an N range or D range and preventing undesired reverse of a vehicle. CONSTITUTION: A control method of an automatic transmission comprises steps of determining whether an engine operates normally(S1); ascertaining a speed range selection state of a shift lever(S4); determining the operating state of common operating elements operating in common in the N range, the D range and an R range if the speed range is in N and D ranges or in the process of N-D conversion(S5); determining whether a vehicle travels at predetermined speed(S6); finding a test speed by multiplying the output shaft speed of the automatic transmission by a reverse gear ratio(S7); determining whether a state, wherein the difference of the input shaft speed of the automatic transmission and the test speed is within in a predetermined range, is maintained for predetermined time(S8); and executing stopping working of a low reverse brake(S9). |
