Patent ID: 7689340

Claim:
A method for controlling operation of a parallel shift transmission having first and second subtransmissions that act on a common drive shaft, said first and second subtransmissions are couplable with a drive shaft through first and second clutches, respectively, wherein one of said first and second clutches is an engaged clutch and the other of said first and second clutches is a disengaged clutch, said method comprising the steps of: during errorless operation of said parallel shift transmission, changing a gear ratio of said parallel shift transmission from a first gear selected in said first subtransmission to a second gear selected in said second subtransmission without any interruption in traction, by disengaging said first clutch of said first subtransmission and simultaneously engaging said second clutch of said second subtransmission, when a malfunction is detected in an actuating device of at least one of said first and second clutches, engaging the disengaged clutch only if at least one of the following conditions is satisfied: a) a previously engaged clutch becomes disengaged; or, b) no gear is selected in the subtransmission associated with the previously engaged clutch.