These are bad codes, you didn't say what kind of mileage and service this has had. The 742 is TCC stuck on and the 1811 is shift adepts at max. Do the basics, check for bad grounds and corrosion at connections. Don't forget to check the battery connections. When was the last tune-up? Vacuum lines? Any add-ons, radio, alarm, air filter?
The bad news is the trans probably needs an overhaul, these are internal leakage problems generally. Always the chance of connection issues or alternator problems and a bottle of lubegard "red" couldn't do any more damage and might buy you some time. Post back, Transman