A:AnswerHello,
I just had this installed in my vehicle to allow steering wheel control. My stereo was a Sony XAV-Ax3000 and I did not need a wiring harness. I only had to pay for install.
A:AnswerAccording to the Maestro website it is compatible with the Pioneer avh-2550nex.
You can plug in your vehicle and radio here to verify - the site is for accessing installation guides, so if it finds a matching guide for your vehicle and radio that means both are compatible with the unit.
https://maestro.idatalink.com/product/product/product_id/101
A:AnswerThis box can be reprogrammed to work for your vehicle. You can check how to do so when you visit the iDataLink site. This device allows you to retain factory steering wheel controls when you install a new car stereo. Buttons can also be potentially remapped when you set the device up from your computer with the microUSB cable included