Citroen C3 the serv light comes on periodically...

Really needs scanning with Lexia or similar to retrieve fault codes , your scanner may not be capable of systems / modules

A diagnostic was run by 2 different auto garages.. GT Autos & Kwik Fit.. would that not have detected any major issue.. Do you think this could be something serious as only bought the car in August..Thank you for taking the time

Really needs scanned by Lexia / Diagbox which is the Citroen diagnostic tool to read the gearbox fault I dont know if fast fit centres are equipped to do this , would doubt it . Only other option is to take it to a local , accredited , auto transmission specialist for examination , report and estimation . But be careful , there are a lot of cowboy , so called specialists out there , check out first . Sorry I cant be more definitive with an answer to help you .