could someone please advice as to whats happining with my 2.5 dse it keeps changing up & down gears on its own have had a few leaks on pump & over flow pipes have fixed them but still the problem persist please help cheers

could someone please advice as to whats happining with my 2.5 dse it keeps changing up & down gears on its own have had a few leaks on pump & over flow pipes have fixed them but still the problem persist please help cheers:)