Now that it is getting colder out, my 2010 impala won't start on cold/rainy mornings. It acts like it wants to, all electric is working, but it won't turnover. It is not garaged. Our repair shop (not a Chevy dealership) has tried everything, including a new sensor. Everything else seems to be in order, yet the problem persists. If temps outside warm up to 50+ it seems to start fine. They now think it may be pcm related, but are not qualified to program the module. Thoughts?