Originally Posted by http://www.itsayellow.com/girls/subaru.audio.html

This is for Panasonic model P113 or P114 80W Cassette/Receiver.
As labeled on the bottom of the unit: Model No. 86201AA350, Ref. No. CQ-LF1111Z.

As Numbered on the female DIN socket:
Pin 1 NC
Pin 2 Line-In Right
Pin 3 NC
Pin 4 Line-In Left
Pin 5 Signal Gnd
Pin 6 CD Play (or Remote Amp In) (send 12V to this to activate amp for remote device)
Pin 7 NC
Pin 8 Mute (input)
Pin 9 Acc Out (filtered power)
Pin 10 Batt Out (filtered power)
Pin 11 CD Stop (input)
Pin 12 NC
Pin 13 Gnd

The story behind this pinout is a long one--suffice it to say that Panasonic SUCKS. They consistently were annoying and completely uninformative to me and my Subaru dealer in our attempts to find the pinout of this connector. In the end I ended up disassembling the whole stereo, reverse-engineering the schematics, and finally figuring out from them what each pin on the connector did. For pins 8 and 11, I'd like to thank Brian S. for his help in identifying them! Probably the logic levels to those two pins are 0-12V just as for Pin 6, but I haven't verified this.

Originally Posted by http://q1.se/cdcemu/details.php

Pin 1 = CD-C data line. (you need to transfer the bytes on this line)
Pin 2 = CD-C clock (you need to keep a 8uS clock signal on this line 4us on 4us off)
Pin 3 = Acc (not required for comms) Note to self: Supply voltage (12V unreg)
Pin 4 = CD-C strobe (you need to send a 4us pulse after the first byte and last byte of packets)
Pin 5 = RM Data (this line has data back from the head unit)
Pin 6 = Acc (not required for comms) Note to self: Supply voltage (12V unreg)
Pin 7 = NC (not connected)
Pin 8 = GND (you require a common ground to head unit)

Originally Posted by http://q1.se/cdcemu/details.php

I often get the question if it's not just a question of shorting two pins. The answer is NO - never try it, it will not work! The radio must receive a valid signal to enable the CDC inputs. If it does not, the CDC input is disabled within a second.