Service AC System indicator comes on.

What is your question?

A couple of months ago, my AC started blowing warm air.. took it to a repair shop and had performed leak detector test as well as checked system.. all looked fine.. Freon level was fine. After a while we disconnected the battery so mechanic could check something else.. nothing found.. so we hooked up the battery again. started up car and AC worked perfectly. Recently, the problem has returned and the only repair i've performed myself was to disconnect/connect battery after a few minutes and it works perfectly again for a few weeks.. Problem now seems to reoccur more frequentlly. Mileage is only 60,000. Its like a hard reset on a computer.. What could be wrong?

How long has your 2004 Cadillac CTS had this problem?

started earlier this year