Going 45-50 mph the rpms go up to 4000 and back to 2000 about 4 times.

I tried to get a diagnostic check from the computer and they said there was no power coming from the computer to check it?

who told you that? try ck'ing cig lighter fuse and repl if blown,that will fix it

The cig lighter does have power.

You are correct Autozone.

Best have a mechanic 'scan test' it for trouble codes.

At aamco and it is free?

auto zone does not have the proper equip to scan,they have code readers

Yes as stated in the 'first' answer; an aamco trans mechanic will test it for free then you can post the codes and we will try to help.

Thank You!! I will let you know the codes when I get them.