drive along then bang,like its dropped into a much lower gear then leaves all theses codes,driven with vag com connected,seems to say its in correct gear,did find loose earth at o/s a post,still no better.codes were.17833/17938/17923/16486/17523/17527/16518/16538. i can post p code descriptions if required.theseare all engine codes.autobox code 18265 load signal error message from ecu p1857. any help/advice would help than ks.