I recently installed a AVIC-W8500NEX in my 98 C5 Corvette, but did not connect the speed pulse wire.  I later decided to connect it.  I connected it at the PCM, but the unit is still giving me the message that the speed pulse wire is not connected.  I have double checked the wiring, and it is connected to the correct VSS wire at the PCM.  Any ideas why the unit is not detecting it?  Does it need to be reset, drove, etc., for the unit to recognize it?  Any help would be appreciated.  I would just like to figure it out before I put the car back together.