There is provided a fail control apparatus for an automatic transmission,
which, in the event of a friction element failure, is capable of coping
with the failure by identifying a failed part without erroneous
determination and within a short time. The set gear ratio of a designated
gear position at the time of failure and the actual gear ratio are
compared with each other to determine whether a friction element has
failed, and an alternative gear position which enables a vehicle to start
moving again is designated based on the determination result. In
determining a failed friction element, one friction element disengaged or
engaged due to failure is identified only when the designated gear
position is the first speed gear position which is achieved by engaging
one low clutch and a one-way clutch. It is therefore possible to
determine the details of failure with accuracy and properly set an
alternative gear position.