avic-n1 reverse signal polarity

I am installing AVIC-N1 in 2004 Honda Odyssey

Pioneer Manual states that this wire looks for a "Change in voltage"

Obvious connection is to reverse lamps but, I can get the VSS signal and the reverse indicator lamp signal from the PCM plug directly behind the display unit for a clean install. 

The reverse signal at the pcm grounds when reverse is selected and a relay is used to switch 12V to the actual reverse lamps.

Is the AVIC-N1 smart enough to determine the polarity when the car is in foreward motion or do I have to tap into the reverse relay output located way across the dash to provide +12V when in reverse?

Thanks auex

How about the "light switch" connection at avic-n1, I have both a +12V lights on signal and a variable "dim" signal available at the vehicle radio plug.

Will the avic "dim" or is this supposed to be a solid 12V when the lights are on?