Just wanted to post my successful results with fabricating a SONY to PB cable. The pinout found on the Wiki here.
http://www.phathack.com/index.cgi?page=pinouts works 100% on the CDX-M650 and I would assume all compatible SONY HU's. The following is the proper pinout to wire color for a factory Sony Unilink Cable. I simply cut off one end of a factory Unilink cable and made the necessary connections to a mouser connector also refrenced in the above link. There are a few connections that require bridges for the +12v and ground to the PB connector, but once assembled, it works marvelously. Sony Unilink cables are relatively cheap so starting from there and attaching the proper PB connector was a financial decision. My diagram is nothing new, just a little reinforcement and confirmation.
1 - Brown - PB function "Ready" - Not connected on PB connector
2 - Purple - PB Function "Reset" - Connected to Pin 11 on PB connector
3 - Orange - PB Function "SIRCS" - Not connected on PB connector
4 - Yellow - PB Function "Clock" - Connected to Pin 24 on PB connector
5 - Blue - PB Function "Data" - Connected to Pin 21 on PB connector
6 - Green - PB Function "Bus ON" - Connected to Pin 22 on PB connector
7 - Red - PB Function "+12v" - Connected to Pins 10,13 on PB connector
8 - Black - PB Function "Ground" - Connected to Pins 4,9,16 on PB Connector