Isx in derate mode showing codes Engine 0 Fail 31 5246 1569

I have a Cummins isx it's in derate mode it's showing codes on my dash which are Engine 0
Fail 31
5246
1569...i had the dpf/doc cleaned i changed the i map sensor also, i also did a park regen on it but after i drove it for about 30 minutes after that the yellow engine light came back on and once I stopped & shut it off then restarted it now the red/yellow light is on and in debate mode could someone please help

 

Looks like I see a 543 on the dash if that any info on helping me ...the def doser valve has a lot of white stuff Aron d it also, could that be the problem?

 

Wow thanks, maybe its in derate because it needs a new doser valve, is it anyway to get it out of derate so i can get it to the shop, also it's a auto, I heard on manual the speed sensor could be unplugged but I'm not sure with automatics