Originally Posted by fu5i0n
you need a steering wheel control adapter that plugs into your headunit, and then connects to your wiring harness
check out AE64.com - he has a lot of good info and even sells the Axxess ASWC and gives great instructions.
i bought my harness and ASWC from him and it made the install of my X940bt a breeze!
Definitely check out ae64.com, if u have the harness already he will sell you the additional three wires for SWC. I bought the wires and the ASWC unit from him a couple weeks ago. The instructions he sends you makes the job go smoothly.