TJ threw this code at me today P1594

[03Jeeper]

I searched but couldn't find anything.

P1594 (G) Charging System Voltage Too High Battery voltage sense input above target charging voltage during engine operation.

I don't really know what this means, but from the looks of it, could the cause be a faulty battery or alternator?
I replaced the batter only a couple months ago. I don't think that would be the problem.

Would corrosion or a loose ground wire have anything to do with this?? 

Any help is appreciated. Thanks.