I just recieved a New z1 back, after I sent the original one back because it had a backup camera issue. the old on (aug. build date)worked very good as far as the by pass goes, but now the newer one does not bypass at all. Does anyone have a solution to bypass the newer version?( I grounded one of the empty four spots in the connector as it was before, but it just keep telling me I hooked it up incorrectly)
Thanks you for any help, and sorry if I missed a previous post on this.

Did you try resetting the unit?

If you followed all the steps outlined here:

http://www.sminntech.com/z1flash.html

you shouldn't have a problem, unless, of course, Pioneer changed the bypass again, which I doubt they did.

they sent me a Brand new unit , are you saying I should try resetting this one?

Yes.

After you bypass it, try resetting it.

You only need to reset the unit if you once tried to bypass the unit incorrectly by permanently grounding the parking brake wire. If you ever did than on a June or older unit, the flashing might not work. But if you used to have a June or older unit and replaced it and the new one isn't bypassed if your date is newer than that, you most likely need the 2 wire ground.