Re: PS4 Plants vs zombies
The splitscreen is accessed on the tv in the back yard.
If the second controller cannot turn on the PS4, it probably needs to sync with the console. Just use a charging cable to plug the controller into the system and then push and hold the PS button until it lights up.
Both controllers need to sync with the system.
This article might help:
https://manuals.playstation.net/document/en/ps4/basic/usecontroller.html
... and more articles troubleshooting splitscreen:
https://answers.ea.com/t5/forums/searchpage/tab/message?advanced=false&allow_punctuation=false&filter=location&location=forum-board%3Apvz-garden-warfare-2-general-discussion&q=splitscreen
Good luck.