Common faults are solenoid(s) not performing correctly or speed sensor fault. Can be verified by road test with scan tool looking at live data. If there is no slipping it is unlikely to be an oil level low condition. For specialist www.fedauto.co.uk
sounds like you have lost some of your auto transmisson fluid,look for any leaks and repair.fill with correct type/amount of fluid, start car and keeping your brakes ON and go though all your gears, to allow fluid to settle. this should cure your problem, if not go to auto transmisson techie, but repairs to auto boxes are expensive. Good Luck.
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