Dolomike

Hey Everyone, I have a circa 2005 Coleman spa (by Maxx) that has a 630 series control system (see the wiring diagram: http://imgur.com/YPKR6T5 ) The topside control is connected to J1 but I was wondering if anyone knows if J2 can be used for a remote panel/interface. I have tried connecting the topside control to J2 but it doesn't work so obviously it has a different electrical interface. Does anyone know what J2 is used for on these older controls? Thanks! Mike