Nexus 6 and appradio?

I have a pioneer sph-da120 radio and a Google nexus 6 running 5.1.1. I have it hooked up to my radio via an HML HDMI splitter but I'm not getting any signal. Pioneer support said its impossible to get a video out signal from the phones charging port but my dad also has a nexus 6 and he was watching TV shows off his phone on the TV with the same splitter. Any replies are appreciated because I'm getting to the point where I want to give up