Ecm went bad and I bought a used one from a guy thinking that any or all ecms can be used. My truck is a 2001 6 speed and when I went to the dealer to have them flash the new one they're saying it's from a 1998. Stupid me I didnt ask what year truck it came off of when I bought it. So the technican tells me I need a 2000 or newer ecm and that there's no need to flash anything it will work. I've spent alot of time reading about this issue and that's the first I've heard that. So I guess my question is what years work with what and does auto/manual tranny make a difference. Thanks for any help. 

From what I understand they are all different, for testing purposes you can put something close in and see but it's not recommended to leave it. 00-02 are preferred ecms with least problems I guess. What did you pay for it, this place can maybe answer your questions 

https://autocomputerspecialist.com

They seem to change their prices a bit, but they help some members here. I had them reprogram a spear ecm I had and activate cold idle too (3/6cyl high idle) for $150 but unfortunately there is still something wrong with it as I lose tachometer after few minutes of driving, everything else seems to work good. They said to fix that it'll be another 150 so I just put back on shelf for now. 

Latest update for ecm is 313038303J I believe. 

@BrianAtSmarty told me once that a 2001 could be flashed to work in my 99. Not sure if it goes the other way. There's a thread here somewhere about 8 months back. Contact him and see what he says. They make a recovery file from your VIN I believe and then re flash or something like that. I tagged him for you, maybe he'll reply.

Indeed as Dave mentions, we can do it. We can use a 98.5 ecm on an 02 or the other way around.

 

Please make a support ticket to me at www.smartyresource.com

 00, 01, and 01.5 are the preferred ecms with the 02 next in line. Manual or auto, no difference.

 

Thank you!

 

Brian