So, It happened to me again. This time was worse then the others. Got off work, 3 AM. It very cold, colder than any night in the last few weeks of having this issue. (40 degrees on my display) I start the car- Starts fine. Battery sounds good, volts are good on display (13v+) All three warning lights come- Service traction control, service power steering, service stabilitrak, along with the check engine light. Car is running and sounds fine. I try to shift into gear, and the shifter moves, but does not actually go into any gears. On other cold mornings, with the service lights coming on, the same thing has happened, or I have been able to get it into limp mode so the car will at least move. After either driving the car to the nearest gas station ( a few miles) or letting the car run for a few minutes (5 minutes or so) , I have been able to turn the car off, let it sit for 30 seconds, turn it back on, and it runs fine- all service lights will be off. On this particularly cold night, this "trick" of letting the car warm up for a few minutes didnt work. After about 30 minutes of the car being on and trying to restart it to get the problem to go away, I decided I needed a tow home. Turned it off, called the tow company. No answer. I decided to try the car one more time before calling another tow company. Low low and behold, car went into gear, everything is fine, and I got it home. I guess it didnt like being threatened with a tow! Continuing, I woke up in the morning- 9 AM- 5 hours after I got it home. Still pretty cold out, 50 degrees or so, to get the car down to the mechanic for a professional diagnostic. The shop is about a mile away. Start the car, put it in gear, and everything is fine. Drive about 1/2 way there, and the car goes into limp mode. get it to the mechanic, and describe all my issues. Update to today, and called the mechanic for an update. He is still trying to diagnose the problem, but its not looking good. The CEL code is U0101, lost communication with TCM. He says he checked the obvious things - Battery, Etc. Battery good. (Less than 1 year old) Recalled negative cable good ( I just replaced it ). He says he has checked for service bulletins or recalls that may pertain to this issue. When he hooks up his scanner, he can communicate with the TCM and all signs say its good. He can communicate with the ECM, and all signs say its good, and when he looks at the ECM, he says it shows that communication between the ECM and TCM is normal as it should be. Basically, ECM and TCM are communicating fine, but ECM is sending the code that they are not communicating fine, and throwing the service codes and putting the car into limp mode by either not letting me go into gear at all, or limiting power. So at this point, he says he is going to look at a few more things, but the next step would be reprogramming the computer and "Hope" that works. Not exactly promising. Doesn't seem to me that software would be affected by the cold weather, but who knows. It seems to me it might be more of a hardware issue with the ECM or TCM, meaning that the cold weather makes a connector or chip in the computers shrink just enough to lose contact, and that when warmed slightly, contact is made again, letting the car run fine. Not sure what to do here- I don't want to just throw spaghetti at the wall and see if it sticks. Flash or replace the ECM (mechanic seems knowledgeable) or take it to the dealer? (Which I try to avoid!)