Spn111 Fmi1 code

Had this code pop up with message:
ECL below Warning/Critical level.
When pulled the code it was "previously active"
One thing I noticed today and for the first time was that Truck did passive regen 3 times in the row, never experienced that before. Other times it was fairly quick, smoked for 2-3 miles and it was done. Today was totally different story and I'm wondering if that code has anything to do with the regen. When I parked the truck and ran NED and I was showing Soot load at 10%. Decided to to run cleanliness test and all Temps were in line (between 1050F and 1100F for both DOC and DPF) Soot level dropped down to 6% which is good.

Anyone have an idea of what that code stands for, I'd appreciate input

 

Gotcha, thanks buddy. Now I know when this code originated, it happened couple weeks ago so not related to regen at all. Kudos to you

 

You are totally right Heavyd, this particular code has been logged right after test ride when I replaced exhaust manifold the first time. I refilled cooling system but I was bit low at that time, I had red stop engine light on. I'm luckily not heaving issues with coolant loss at least for now, nonetheless I appreciate your input.