2006 prius overheating?

hi my 2006 prius is giving me a problem, it seems to be going thru transmission fluid about a 1/2 quart a day or more. the check eng. light is on and the red tempture sign is on the mfd also yellow ! with a circle and ( ) around it. It dosent have to power in the gas peddle when you push on it. now here is the kicker, as long as the transmission is full no problem, oh and by the way does not seem to have a leak anywhere I did check the oil that also seems to be ok, not milky the codes it is stating are p0116, p0017, p0138, p1150, p01151. I dont have a toytota ITT yet but i am working on that, (has anyone used a denso toyota ITT 2 before?) I have a obd reader so that was the codes it gave me. I think p0016 is the timing belt? p0117 is coolant p0138 02 sensor bank 1 sensor 2 (not sure what that one means) p1150 and p1151 heat storage, ok when the transmission fluid is full the car will run fine, but as soon as it is low it blows all these codes. Where is the fluid going? the p0016 has been on there for a while, so that code is not new. so this is alittle puzzling. We do all our own repairs, but still learning so anyone with any info would be greatly appreacted. Thank you. also please dont tell me to go to toyota been there done that not an option I have more knowleadge than they do. Thanks!!