I just pulled out my shop manual 2007 Dyna and if it truely is #31 it is labeled Battery in my book and BE/GY and goes to the system Relay as well as the ecm fuse 15amp other side of fuse goes to Battery / ignition switch / and maxi fuse as well as supplies Battery line to another fuse on the fuse block.

now if thats the case i would say you need to fix it soon.

Now it its #32 its unused
#33 is Vehicle speed sensor
#34 unused
#35 Idle air control (A) low
#36 Idle air control (B) High

 

My guess is that it is supplying some form of constant power ( battery ) to the ecm what the ecm uses that for is unknown??

 

yes, constant power is right.....anyone know what would happen if I run without #31? I called the Dealer and they basicly said we don't install pc111, so we can't help you, WTF? I was trying to avoid the inevitable, which is having to buy another powercommander because of one broken pin.