It is disclosed a
system and method for maintaining the operation of an automated transmission (16), particularly a dual
clutch transmission, for a motor vehicle, in case of a failure of an engine speed sensor (50) or a
bus connection (44) between a first control module (42) controlling an engine (28) being connectable to the transmission (16) through at least one separation
clutch (12, 149, and a second control module (34) controlling regulating units (12, 14) for connecting the engine (28) to the transmission (16) or to one or more driving wheels (34) in a force-transmitting manner, wherein gear-shift relevant data, particularly a number of revolutions (ne) of the engine, is exchanged between the control modules (34, 42) over the
bus connection (44), the method comprising the following steps: checking whether a number of revolutions (ne; n1, n2) of a shaft (22; 30, 32, particularly an engine shaft (22), which is detected by a sensor (50) of one of the control modules (42) dedicated to this purpose can be transmitted from the one of the control modules (34, 42) via the
bus connection (44) to the other one of the control modules (42, 34); and performing the following steps, if the number of revolutions cannot be transmitted: opening all
synchronizer devices assigned to the transmission (16) or one of the partial transmissions (18, 20) so that the engine shaft (22) can no longer transmit force via a transmission shaft to the driving wheels (33) of the motor vehicle; closing the separations
clutch (12, 14) assigned to the transmission (16) or the partial transmission (18, 20) by means of the opened
synchronizer devices, if this separation clutch (12, 14) is not closed; detecting a number of revolutions (n1, n2; ne) of another shaft (24, 26), particularly the transmission shaft, which can be connected to the shaft (22) through the separation clutch (12, 14) by means of a sensor (36, 38) of another control module (34), wherein the sensor (36, 38) is dedicated to this purpose; and determining a gear-shift
ramp function for one of the control modules (34, 42), preferably the second control module (42), based on the detected number of revolutions, particularly from a field of characteristic lines, for allowing performance of a shifting process from a source gear to a target gear (FIG. 4).