Patent ID: 8635926

Claim:
A system for controlling a vehicle, the system comprising: a prime mover including an output shaft; a transmission having an input shaft, a clutch assembly, a plurality of gears, a plurality of torque transmitting devices, and an output shaft, wherein the clutch assembly includes a friction clutch that rotationally couples the input shaft with the plurality of gears, and wherein the plurality of torque transmitting devices are selectively engageable with the plurality of gears to establish a plurality of speed ratios between the input shaft and the output shaft; a first sensor configured to detect a rotational speed of the input shaft of the transmission and output a first signal indicative of the speed of the input shaft of the transmission; a second sensor configured to detect a rotational speed of the output shaft of the prime mover and output a second signal indicative of the speed of the output shaft of the prime mover; a transmission controller in electronic communication with the first and second sensors and operable to control the transmission by selectively engaging the plurality of torque transmitting devices, wherein the transmission controller includes control logic comprising: a first control logic for controlling the transmission using the first signal of the first sensor; a second control logic for performing a diagnostic check on the first sensor; a third control logic for determining whether the diagnostic check of the second control logic indicates that the first sensor meets a predefined performance characteristic; a fourth control logic for instructing the transmission controller to use the second signal of the second sensor to control the transmission if the third control logic indicates that the first sensor does not meet the predefined performance characteristic; and a fifth control logic for controlling the transmission using the second signal of the second sensor.