Patent ID: 7264573
Filing Date: 2007-09-04
Classification: F16H,Y10S,Y10T

Abstract:
1. An automatic transmission control apparatus for controlling a gear position by operating engagement and disengagement of a plurality of frictional elements, the automatic transmission control apparatus comprising: first low-pressure detecting means for detecting first hydraulic pressure, which is applied to one of the plurality of frictional elements, to output a first-low signal by comparing the first hydraulic pressure with a first-low threshold; and first high-pressure detecting means for detecting the first hydraulic pressure, which is applied to the one of the plurality of frictional elements, to output a first-high signal by comparing the first hydraulic pressure with a first-high threshold; wherein the first-high threshold is greater than the first-low threshold; the automatic transmission control apparatus further comprising: failure determining means for determining a failure in the plurality of frictional elements in accordance with the first-low signal and the first-high signal; second low-pressure detecting means for detecting second hydraulic pressure, which is applied to another one of the plurality of frictional elements, to output a second-low signal by comparing the second hydraulic pressure with a second-low threshold; and second high-pressure detecting means for detecting the second hydraulic pressure, which is applied to said another one of the plurality of frictional elements, to output a second high signal by comparing the second hydraulic pressure with a second-high threshold; wherein the second-high threshold is greater than the second-low threshold, said one of the plurality of frictional elements and said another one of the plurality of frictional elements are probable of causing a dual-engagement, and the failure determining means determines occurrence of the dual-engagement in accordance with the first-low signal, the first-high signal, the second-low signal, and the second-high signal.