I searched this, ls1tech, and google searched both forums. I am trying to figure out exactly how to go to a p59 ecm. I have a 2003 express van. Serv 12576106, hdw 12570558. Before I repin the connectors. Am I going to write entire my Silverado file into the ECM? Or do I just work off the Van and now my truck thinks its a Van? The reason for all of this is to go 3 Bar and A/C fan control. If I do keep it as a van do I use the segment swapper? Also do I change the System Platform to GMT610 to GMT800?
Eric