Does anyone know what is involved with DMU exams? I know that there are A Exams - basic, roughly every 20,000 miles or so. Then more detailed B Exams. I think around 40000 miles. What do different TOCs do? As far as I know Transpennine Express focus on 185 unit exams at Manchester although there may be minor Exams at York? Northern work around their main depots but do carry out A Exams at Hull. Hull Trains at Old Oak but minor work at Hull.