AUTOMATIC TRANSMISSION CONTROLLING SYSTEM AND METHOD WHEN A POSITION SHIFTING SOLENOID IS FAILED

摘要

PURPOSE: A device and method for controlling an automatic transmission when a position shift solenoid is failed are provided to accurately measure the change gear ratio of a present vehicle by using the speed of the vehicle before/after the vehicle passes through an automatic transmission. CONSTITUTION: A method for controlling an automatic transmission when a position shift solenoid is failed is as follows. It is confirmed whether a driver has an intention of shifting a gearshift to an R position(S10). The I/O velocity ratio of an automatic transmission is calculated by confirming the input and output velocity of the automatic transmission(S20). The I/O velocity ratio of the automatic transmission is compared with the gear ratio of the R position(S60). It is confirmed whether a position shift solenoid is failed(S40). [Reference numerals] (AA) Start; (BB) Checking the input velocity(Vi) and the output velocity(Vo) of a transmission; (CC) Calculating the input/output velocity ratio(Vo/Vi) of the transmission; (DD) Confirming a normal state; (EE) Confirming a failed state of a position shift Sol.; (FF) End; (S10) Gearshift→R position?; (S100) Third failure warning; (S30) Vo/Vi≠Gear ratio of R position?; (S40) Confirming a failed state of the position shift Sol.(Gear shift Sol. = Backward driving Vo/Ci = Forward driving); (S50) Gear shift solenoid→N position or first failure warning; (S60) Vo/Vi = Forward driving gear ratio?; (S90) Second failure warning