so I’m wondering if someone can help me out here.. so I’ve got a 03 Silverado 3500 and I bought a 01 Silverado 2500 that was wrecked and I put the motor in my 03.. didn’t have any issues swapping besides when I put the ecm from the 01 into my truck.. it won’t start with the key.. with my old ecm in.. it starts no problem. The new ecm has hotter tunes on it.. that’s why I want to get it working in my truck but I’m unsure what the issue is.. it won’t crank over but if I jump the starter it will start but the dsp5 switch also doesn’t work. I know the truck stared before the swap. Someone’s gotta know the reasoning for this.. thanks in advance!!
01 lb7 ecm into 03 truck
- Thread starter Dirtymaxx73
- Start date
As far as I know, VIN doesn't matter... More likely security or the simple matter of a 2001 ECM in a 2003... For those more in the know, will a 2001 ECM/OS plug n play in a 2003 truck??
I attempted to respond the other day but for some reason it didn’t post.. I had the vin number on the ecm changed..
Like I said it won’t turn over with the key.. I can jump the starter and it runs fine but when I did that the dsp5 switch didn’t do anything when I switched to any other level and in the previous truck when you switched the level with the switch you could hear the change in the way the motor was running. If I could get the switch to work I’d just put a push button to the starter.
Can’t remember. I’ll have to put it back in and see. I got the ecm from my 03 in it and it works with that one
Not sure what you mean by that. I’m not one to just say it is what it is.. that’s like accepting defeat which I don’t do. Gotta find out what needs to be done to I make it work.
I'm not an expert on the pre 03 electrical architecture, but there were pretty significant changes with the electrical architecture from 02 to 03, so it's possible that, while pin compatible, there's a difference that will simply prevent an 01/02 ecm os from working in an 03/04 truck. I'm sure there are at least one or two people here that know more than me in that arena ..
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I kind of doubt it's CANBUS related, since from 2001 to 2005, it wasn't CANBUS as we know it, but more industry standard J1939, and only between the ECM and FICM(FUCM).. I'd put it more on something class 2 related... I'll try to look something up tomorrow...
Not EXACTLY LOL. J1939 and GMLAN are very close, but not the same or directly compatible. Kind of like one person speaking German and another speaking Italian. Class 2 isn't even close. Different pin on the dlc and totally different category.CANbus, J1939, class 2, all the same thing
Yeah, I'm aware. I just keep forgetting what years use what communication protocol so I sometimes just throw one out. Often getting it wrong
