Can someone plese tell me what the TSB for my 2003 Tahoe rear heat is or where I can find out about it? I took it to my local dealer because the rear heat is not blowing hot air just cold and all they told me is that there is that they found a TSb for the HVAC control Module and Air Temp Actuator.They told me it would cost $557.56 to fix. Im just trying to find out what is wrong with it some maybe I can fix it myself and save some money. Thanks a lot.