you do not give engine size or year of your sharan, i will give what info i can, i have a 2 lt 97 model and it has an electronic switch that governs the gear changes, its possible yours is on its way out, it is located towards the back of the autobox, but you need to drain the transmisson fluid to take it out.
it could just be low on fluid, get a copy of the haynes manual (£20 from halfords) you need to get the ford galaxy book but the mark 1 galaxy's & sharan's are the same, this will help you out a bit as auto gearboxes really need a specialist to look at it properly and this can be expensive. good luck.
billsp, April 2012
