Anyone know what this wire is in the Sony head unit harness?

I am replacing my aftermarket stereo in my 2006 Tacoma, and see this busted wire in what I believe is a factory harness. Anyone know what this wire is or if its useful? I am replacing a Sony XNV-770BT, which I partially installed in 2010 and had an audio shop finish, with a Jensen Car910X, and discovered the severed wire.

I am not sure if it happened pulling the older head unit out, or if it has been that way for a while and made no obvious difference.

 

Aux or SWC. Not much else it could be for an 07, I’m not even sure the 07 had SWC.

 

yes, turns out it was the SWC. It must have gotten severed recently. Took out the Sony which was a bit dated, with a Jensen with floating screen and Apple Car Play.