Help for a friend.

[Rigbyy]

He has a E46 2001 318i Auto. A small cog symbol next to what gear he is in has appeared, although not all the time and it makes the up changes jerky and down changes clunk. It had the gearbox oil flushed today and it fixed it for a while but has just come back on. Seems to me to be a sensor as when you turn the engine off and back on the light goes off and its as normal.

Has anyone else had this problem?