Hello all! Forgive me if I'm beating a dead horse, but I'm trying to run/simulate a GMLAN cluster with the ECM, TCM and BCM. Thus far, I am able to power up a 2007 Silverado, simulate Oil, Fuel, Water temp & Battery voltage, plus drive the Speedo. I'm having an issue with driving the Tach. I'm just curious if I need an alternative function generator to drive it or if I'm missing a/some component(s). Also, are the GMLAN clusters universal? Say if I wanted to use my 07 Silverado setup and run a 09 Cobalt, would I need anything else to drive it? Thanks.