I got the "T/M system malfunction" warning this morning, with the battery symbol lit up. It was 7degrees out and I had just removed the trickle charge cable with 100% capacity showing. The shift lever would not engage either forward or reverse but would only go into neutral. Called the Nissan service and they had no suggestions except to have it towed into them. Tried in vain for about 15 minutes, and walked away-returned for another try 15 minutes later and everything was normal. What happened?