I have the NYC version of this locomotive. I learned that it is sensitive to low track voltage and couple that with more than 4-5 cars it will stall and throw a code.
My solution - added another power drop to the back-end of my layout (I have a small 5x9 with one Powerhouse 180 and lock-on) and I only run it with 2-3 cars. These are geared pretty low and are not designed to handle more than 3-4 cars for an extended length of time.