Patent ID: 8271168

Claim:
A shift controller of a vehicle automatic transmission, comprising: a shift control unit that automatically shifts gears of the automatic transmission on the basis of a vehicle state by referring to a prestored basic shift line map; a shift line map switching control unit that switches from the basic shift line map to a high fluid temperature shift line map when a hydraulic fluid temperature in the automatic transmission is higher than a predetermined fluid temperature determination value; and a low power state determination unit that determines whether a vehicle is in a low power state in which a required power related value of the vehicle, used for gear shift determination in the shift control unit, is lower than a predetermined low power determination value, wherein the shift line map switching control unit switches from the high fluid temperature shift line map back to the basic shift line map when the hydraulic fluid temperature in the automatic transmission is lower than the fluid temperature determination value and when the low power state determination unit determines that the vehicle is in the low power state, and each of multiple shift lines of the high fluid temperature shift line map is set on a lower speed side with respect to corresponding multiple shift lines of a low fluid temperature shift line map in a higher power region respect to the predetermined low power determination value.