Control apparatus for hydraulically operated vehicular transmission

A control apparatus for a hydraulically operated vehicular transmission having a plurality of speed stages to be established by a selecting operation of a plurality of hydraulic engaging elements, comprising:

• detecting means for detecting an input to output speed ratio of the transmission;
• outputting means for outputting a speed change command signal when a speed change is to be performed;
• a first speed change control means which, upon receipt of a first one of the speed change command signal to be outputted by said outputting means at a time of non-speed changing, performs a speed changing corresponding to the first speed change command signal by controlling a hydraulic pressure of an off-going hydraulic engaging element to be disengaged at a time of speed changing and a hydraulic pressure of an on-coming hydraulic engaging element to be engaged at the time of speed changing depending on the input to output speed ratio of the transmission and on a time of lapse from receipt of the first speed change command signal;
• a second speed change control means which, upon receipt of a second one of the speed change command signal to be outputted by said outputting means during said speed changing by said first speed change control means, performs a next speed changing corresponding to the second speed change command signal by stopping said speed changing by said first speed change control means;
• means for discriminating whether a detected value of the input to output speed ratio of the transmission to be detected at the time of non-speed changing lies within a predetermined range which is set based on a gear ratio of a speed stage that is being established at the time of non-speed changing, and for outputting a normal signal when said detected signal lies within said predetermined range;
• and
• means for prohibiting, if the normal signal is not outputted when said first speed change signal is received, said next speed changing by said second speed change control means upon receipt of said second speed change command.