ATF - Automatic transmission fluid.
There will be a filter but they are usually housed inside the auto box oil sump. It has to be drained and the sump removed to gain access to the filter.The only ones i have seen are quite flat to look at and held to the bottom of the auto box with a couple of bolts. As i've never worked on a B-max auto i cannot say for sure that it will be the same setup as other auto boxes but they all seem to have the same design.
Thanks milkyman, I wouldn't - couldn't do that, I would rather pay the experts.
This is my wife's car, 29000 on the clock. Moved it yesterday and saw a red (i) and a yellow spanner on the warning panel. Nothing about the spanner in the book. Message showing transmission fault.
Called Ford dealer where we bought it from and they have booked it in for a service.
Thanks for your help, I expect I will be here again.