Mystery cut wire

[brokenbimmer533]

Last time I changed my oil, I was browsing around my engine bay and found this wire.
Heres a picture with the insulation pulled back. Yellow, Brown and Blue wires.
Here is where it enters the firewall. Its the wire in the center of the picture. Its between the fusebox and the brake booster

Any help is greatly appreciated.
Thanks
Nate

[brokenbimmer533]

Just looked again. The second picture is incorrect. That is the cruise control servo wire I believe. The mystery wire goes into a bundle that goes under the fuse box.