A:Answer Hi, Help!
Please try to reset the car stereo to factory default settings and try again. See page 8 on how to.
https://www.sony.com/electronics/support/res/manuals/4597/6fe8b5239ed33903bf19065df648d08d/45971436M.pdf
If resetting didn't resolve the issue, there must be an issue with the wirings of the car stereo. Sony recommends that the installation be completed by a professional and qualified installer.
Regards,
David