The firmware update directions say that the car must be stopped and the parking brake engaged.  I have a by-pass installed.  Does the updater look for the ground from the p-brake wire and if so will the by-pass work?  I know it does the pulse thing.  I just thought it was strange that this was in the directions but didn't see anyone on the forum talking about it.

The firmware update directions say that the car must be stopped and the parking brake engaged.  I have a by-pass installed.  Does the updater look for the ground from the p-brake wire and if so will the by-pass work?  I know it does the pulse thing.  I just thought it was strange that this was in the directions but didn't see anyone on the forum talking about it.

I believe that's just to make sure that you run the firmware update while you're parked. The bypass should work to allow you to run the update because your head unit will think the parking brake is on. At least that's how I understand it. I haven't run an update yet on my Appradio 4. 

I think I may have read once that somebody performed a firmware update while driving (not advised), so apparently his bypass was working.