waking up amplified ant. on 2001 audi S4

Replacing the Bose system in a 2001 Audi S4 using a Premier DEHP840 ,Jl Audio 300/4,Jl 500/1,10w7 and XR components. Trying to wake up the factory ant amp mounted on the bottom of the Nav & Changer Mount.  It is a similar unit to the ones found on C & S class benz and found on most BMWs. The unit has ground and constant 12 volt pins..the colors are brown(reading ground) and RED / w blue trace(reading constant 12 volts)   Does this unit use a Hi or Low voltage trigger multi-plexed thru the coax? There is no reception unless the factory deck is re-connected. The pioneer unit and adapter have been tested with no problems found. Any information about this system or suggestions would be very helpful.