Control apparatus and control method for an automatic transmission for a diesel engine

A control apparatus for an automatic transmission for a diesel engine is applied to a vehicle (1) in which is mounted a diesel engine (11) in which fuel is injected based on a comparison between a required value (qireq) for a fuel injection quantity determined based on an operation amount (Accl) of an accelerator pedal (AC) and a maximum injection quantity (qilmt), and the maximum injection quantity (qilmt) is corrected based on a predetermined running parameter. A downshift is then performed in a transmission (12, 13) when the required value (Tereq) for output from the diesel engine (11) calculated from the operation amount (Accl) of the accelerator pedal (AC) is equal to, or greater than, an upper limit value (Telmt) for the output from the diesel engine (11) calculated based on the maximum injection quantity (qilmt). Accordingly, a gearshift is able to be realized that is appropriated for the running state of the vehicle.