[ChevyGuy]

My 2013 factory manual does't show anything for a P3100. Nothing up in that range. There is a code for B3101.

And I think using electrical cleaner on the belt is a bad idea. You might have a belt change in your future. The belt change isn't all that easy - you have to remove an engine mount to do it.

 

[ChevyGuy]

You might want to go to a parts store and ask them to read the codes. Your scanner may be misinterpreting things.