No one really had any idea why it says this in the install when I asked about my D3, but now I'm going over the Z110BT manual and the same odd entry says:

"This product cannot be installed in a vehicle without ACC (accessory) position on the ignition switch."

Why does it say this?

Thanks.

It might have something to do with the yellow ACC wire on all harnesses. Without this I think any memory will be erased whenever the car shuts down. This would be a potential problem for the radio. Maybe more of a chance to shock the unit also. Since the ACC wire provides some type of power constantly to the unit.

I got to thinking about it and it could actually be for a specific type of older make vehicle. What strikes me as odd is that specifically mentions that "on the ignition". A head unit install is pretty easy, but not so easy that you need to put such dumbed-down instructions like that; so I'm wondering if it meant something else.

I e-mailed pioneer support; I really don't expect much of an answer as I'm sure they get all sorts of basic questions and aren't used to getting questions that aren't already covered in the FAQ/manual.

The only though I did have was that it needs a fraction of a second to wake up before the power gets cut again from the starter . . . maybe to account for power fluctuations. That's sort of a drawn-out answer to something probably simple, but who knows.

My car has a stop/start button no ACC is figured in, unless I leave the clutch out when I hit the button. It *does* behave like a regular ignition; there's a fraction of a second to power everything up, then it turns over etc.

I'm not all that worried, just interested to know WHY they'd phrase it that particular way.

As long as you have it on your car you have nothing to worry about.