P04DB cel

Alright so I'm new here so I'll start with a little back story. I purchased a 15 ecodiesel October 29th with 42k miles on it. On the drive home the check engine came on. I have a choice reader so I pulled the codes and P04db was in there 3 times. It appears somebody knew it was a problem and cleared the codes. I wasn't worried because I bought the extended warranty. The next available day I brought the truck back to the dealership and that's where my problem starts. They tell me it just needed a PCM update and gave it back to me light gone for a day or two. Comes back on and the truck goes straight back to the dealers. They say bad crank case pressure sensor they had it a couple days and then gave it back with the light gone for about another day. Back to them the third time and they say is the PCM and replaced the entire unit and gave it back and the light came back on 9 hours later after maybe driving 50 miles. So that beings us to now, my truck is at the dealership for the 4th time and has been since I think the 9th of December, I have a star case with Ram, and they have called me multiple times to update me which is great except every update has been "we don't know anything right now". The dealers called me last week and told me everything they have checked per Ram with no results and no updates since. So I guess my question is has anybody else had any issues like this and how long would you let it go before you brought up a lemon law case? I've read about the turbos getting cokes and oil in the intercooler and people getting this code when they attempt to modify the crank case breather with a catch tank for any oil but I haven't found anybody just have this problem by itself. I'm at a loss on this.