Need some help. Built up a 103" replacement engine and I want to keep my old 88" and the orig ecm together when I do the switch. I purchased a used ECM to put on the bike and have it reflashed for the 103, It is the correct part# and year. But when installed on the bike it starts up and dies immediately, this will happen 3 times and then the security lite comes on and now the starter will not work or engage at all. So I take it there must be a interface between the ECM and the security system ? Put the old ECM back on and everything is fine. Anybody know how to or what I need to do to make this work ? I don't want to put out the $ for a reflash if this is possibly a junk ECM, The man I purchased it from says his bike ran just fine. [He wrecked it and is parting it out]

 

grab an electrical diagnotics manual for your ride. It has all the instructions for "marrying" the ECM including the password learning that needs to happen...

 

OK. Will check @ the dealer today, I also run a thundermax ecm on the bike and when I installed it. There were no problems what so ever, Everything worked as it should right from the start. I have always carried my orig. ECM just in case - kinda puts the mind at ease if your out of state and something was to happen with the thundermax just unplug it replug the old ecm and on my way again. [ Not kickin on thundermax ] it's just a little insurance is all. The marrying and password ? - I figured being a stock piece you would be able to plug and go ? - I Will check this out ! Thank's