Control of a vehicle having an automatic transmission to compensate for ambient air density

摘要

A method of controlling an automatic transmission (24 fig. 1) of a vehicle (10), the method comprising receiving a signal indicative of a vehicle operating mode 54, obtaining a base map defining gear shift points for the transmission based on the indicated vehicle operating mode 56, obtaining a torque loss map defining gear shift points for the transmission based on a predetermined minimum value of density 62 and controlling the transmission based on the base map if the base map defines gear shift points at higher engine speeds or vehicle speeds than the corresponding gear shift points defined by the torque loss map. The method may comprise receiving a signal indicative of the ambient air density such as barometric pressure, navigational data, surface gradient, or ambient temperature. A compensated map 64 may be determined based on the signal indicative of air density and may be define shift points that have been interpolated between the torque loss map and the base map.