evap p0446 in the rain

[Gaster]

Hello i am new here so i wanted to start by thanking everyone that may look at this post. i have a 2012 Silverado 1500 5.3 4x4 crew cab with 38K on it. the truck i like brand new and i have owned it for 5 months. well now that winter has hit i started getting a p0446 error code. i have read tons off forums on the topic and have tried all of the normal cleaning of the filter, checking connection, blowing out and testing the control valve. i have read one topic about water intrusion causing this and i believe that is my problem. the last time i cleared the code we had over a week of dry cold weather and no code appeared. well the last two days it has been raining hard and when i remote started my truck this morning it ran for about 2 minutes and shut down. the code came back. it has only ever set the code while running in remote start and when it is raining. so my question if this is a water problem were should i be looking for the short? the truck sits outside as it is to big for my garage.

Thanks in advance for any help!