there has to be a trouble code still stored in memory for that light to keep coming on or flashing. try a hard reset by disconnecting both battery terminals and touch them together, that should clear caps and reset codes. recheck for any pending codes, a relearn is not possible with a pending code. if the vehicle drives fine and shifts through all the gears with no trouble codes, I will suspect a bad tcm. usually a bad solenoid either shuts down the driver in the tcm or fries it. a relearn can also be perform by driving the vehicle for a few miles.