I have 2009 Equinox and it has been acting weird since a month. It starts locking and unlocking itself and loses power, no matter how much gas i give moves really slowly. If i pull over and let it cool down then comes back to normal. The mechanic had it for 2 weeks and said it didn’t show the symptoms as long as it was there, but said it needed transmission module from my description of problem. And after 5 days it started again. Please help me