Re: Code U0404 Jeep SRT8 2006
If you google that code it indicates that there was a loss of communication from the shifter. Its a somewhat common problem, there are threads that show how to disassemble the shifter and clean the contacts. You can also replace the assembly which is around $400 the last I heard.
2015 Billet Silver
2012 300SRT, 2009 Jeep SRT, 2006 Charger SRT
Too many mods to list for each, so let's just say a lot was done over the years.