2000 Vauxhall Vectra

Transmission problem
2000 Vauxhall Vectra 4 cyl Two Wheel Drive Automatic 100000 miles

car I just bought, it goes really well through all gears when cold and after it heats up after say 20 miles or so the computer comes up with " automatic gearbox" and seems to switch the automatic shift system off. I then select gears manually, if I stop and switch ignition off and on again it will travel fine through the gears in automatic mode but resorts back to me making manual selection within a minute or so.
I have had a diagnostic test done and they said it wasn't repairable the codes that come up were PO715 input turbine speed sensor fault----next one was PO773 shift solenoid E Electrical.
I have changed the transmission fluid but no difference, old fluid had very, very slight tinge of yellow at bottom of basin I used, no metal shavings were to be found in old oil.
Do you think its a possible repair job without removing transmission your help advice would be much appreciated.
Thanks Alan
Meredith inkster
June 3, 2010.

Both faults are electrical and repairable by a good transmission shop. Replace both solonoid and sensor. The transmission will probably have to come out of the vehicle to do this. But it is much cheaper than a new transmission

Dave H
Jun 13, 2010.
Fluids (ATF) get thinner as it get's hotter the solonoid valve is probably letting fluid through when it is thin (hot)... it is not designed to do this and the electrical sensor part of the valve is picking up on the loss of pressure on the solonoid valve due to the leak then switching it over to manual shift .. there may be a service bulletin regarding this from vauxhall/opel ? could be a common problem with this transmission/solonoid

Dave H
Jun 13, 2010.