Email caspers through their help form. I got my response there directly from them. I believe the fast wiring for their egr harness only uses Analog aux input 1 and 2 which should be listed on the instructions as C connector pin 12,13. I believe they are programmable in the software so either one can be made work but as far as what the caspers box is doing w the inputs they will give you the right answer. This is helpful if you're making your own harness. hope this helps