96 Jeep GCL tranny problems i think

[timmy_davis]

i have a 96 jeep GCL it will run about 3 miles and the over drive will kick out and it will not have first gear i can shut it off and restart it and it will do the same thing all over again it showed 4 codes 12, 15, 37, and 55, if anyone can help it would be much appreciated. i have changed the tranny fluid and filter, cat, and thermostat but did nothing.