A hydraulic control circuit for an automatic transmission of a vehicle,
the transmission including hydraulically operated coupling devices at
least one of which is selectively operated to establish a corresponding
one of speed steps, the hydraulic control circuit including
electromagnetic valve devices which output respective hydraulic pressures
to operate the hydraulically operated coupling devices, respectively, an
all-fail detecting and switching valve device which is switched, based on
an all-fail state of the electromagnetic valve devices in which none of
the electromagnetic valve devices output the respective hydraulic
pressures, to an operation state corresponding to a fail position to
output, as a first hydraulic pressure, a source hydraulic pressure to a
first hydraulically operated coupling device out of the plurality of
hydraulically operated coupling devices, and an operation-state memory
valve which is switched, based on a state of the vehicle before the
all-fail state occurs, from a non-running position indicating that the
vehicle is not running, to a running position indicating that the vehicle
is running, which is kept at one of the non-running position and the
running position, and which supplies an operating hydraulic pressure to
one of a second and a third hydraulically operated coupling device out of
the plurality of hydraulically operated coupling devices that corresponds
to the one of the non-running position and the running position at which
the operation-state memory valve is kept.