Okay I figured out that the E-brake has to be on. Now I have a question about doing the bypass. What does the mute wire do that it should be grounded as well? and how or where can I find out how to take the head unit out?
Thanks
You need to read the Hardware Bypass for Dummies thread, and that's not an insult, but the name of the thread. It will answer "why the mute wire" "what to do with the mute wire" "what to do with the other wires"
Scion doesn't install the AVIC "at the factory" it was done by either the dealer, or a local shop for the dealer, and they didn't do the bypass for sure, nor should they, there are safety and legal issues. However they should have hooked the parking brake lead as would be described in the installation manual.