Mac_MN

Yes, I wasn't intending it to be a question, just a possibly helpful example of how I got the P059F code that might be of use to others encountering the same situation.

Yes. Went through a touchless car wash (lots of spray and limited drying) and drove the 2 miles home, air temp approx 10F. It stays outside since the boat occupies the stall next to the wife's car in the garage. Air temp stayed below freezing until the next day. Got several miles down the road and the engine light came on. Onstar gave me the code and the explanation. I noticed that the engine was not reaching its normal operating temp. Scheduled a dealer visit for a day later but since the engine warmed to normal operating temp on the way, I figured the grill shutter had thawed out at some point. Dealer checked it out, found nothing. Since I don't have a garage for it, I don't get it washed now until the air temps get above the mid 20s. Not ideal since they salt the snot out of the roads up here every time there's a 1/2" of snow.