| 摘要 |
PROBLEM TO BE SOLVED: To accurately carry out the judgement when the trouble or normality of gears is judged by comparing the gear ratio of a target gear step based on a speed change command with a real gear ratio, in an automatic transmission. SOLUTION: This device is constituted, for example, at the fourth speed order time, so that a gear normality is judged when the deviation for the gear ratio C4 of the fourth speed of the real gear ratio GR calculated from the input number of rotation and output number of rotation of a speed change gear mechanism is within the range of prescribed deviationsα4L,α4H, while the gear trouble is judged when the deviation of the real gear ratio GR becomes larger than the prescribed deviationsβ4L,β4H set to a larger value than these prescribed deviations and the real gear ratio GR is within the range of prescribed deviationsα3L,α3H for the normality, judgement set for the gear ratio G3 of a third speed. |
