| 摘要 |
A motor vehicle has a driving engine, a clutch, an engine rpm transducer, a transmission, at least one driven wheel, and at least one speed transducer, in particular for ascertaining a vehicle speed or a power take off rpm of the transmission. The at least one speed transducer is equipped with a transducer wheel having one of a first and a second given number of teeth. An electronic control unit includes a clutch recognition device supplying a clutch signal when the clutch is engaged. A calculation circuit ascertains a ratio between the engine rpm and the vehicle speed. A comparator compares the ratio with a predetermined threshold value and supplies an output signal associated with the transducer wheel having the second given number of teeth if the ratio is less than the threshold value. A memory provides nonvolatile storage of the output signal if the clutch signal and the output signal are simultaneously present. The vehicle speed is ascertained from the number of teeth of the transducer wheel associated with the output signal stored in nonvolatile memory, or the number of teeth associated with a specified signal associated with a transducer wheel having the first given number of teeth, if the output signal stored in nonvolatile memory is not present.
|
