I'm installing a GMT4 into a 2013 express van using the standalone option (connection c) in the instruction manual. The yellow/black wire says it is supposed to connect to the "start/stop external control". The wire diagrams from wirecolor.com do not reference this wire. What is it referring to? Also, is a hood pin or valet switch required for the unit to to work? Last, does the evo-all unit require programming if I'm using the FLU2 to enable option 15? If so, what is the purpose of this programming?