I have a 2013 Nissan Sentra SR and the transmission fluid has been overfilled by 4 quarts. To top it off it’s been overfilled with regular ATF. Car went into like a safety mode I think. I’m getting 4 permanent codes of P0846, P2859,P285A & P0712.

Since then the fluid has been drained down to proper level. But car runs when in park and when I give it some gas the RPMs barley move. Idles fine. Also when putting it in any gear it just rolls.

My questions are is it in like a limp mode to stop further damage or is my transmission TOAST.

Thank you all for your help.

The valve body will definitely be shot, it only takes a couple teaspoons of regular ATF to screw them up. But you can't just replace the VB, there will be ATF inside the torque converter which will be impossible to flush. If it can be saved at all, the tranny will need to be split away and the converter replaced along with the VB, and all the passages purged with solvent and compressed air while the VB is out.

Would you try and fix it or just buy a replacement?

It's trash. The VB and TC together will cost close to $2K, and then it needs all that labor to scrub it out, and then you still might find issues with the belt or planetaries. A reman tranny is $2K from NissanPartsDeal, or you can look for a good used one with the matching TCM that will be plug-and-play.