Vehicle is a 2005 Silverado 1500 5.3, just found out my 'crank, no start' intermittent issue turned out to be a bad ECM. I was thinking about just picking up a used one from a pick-n-pull scrapyard instead of a brand new one at Autozone or something.

My local mechanic told me I would have to have the dealership program it, is this something I can do myself to save some money?

A friend of mine told me I could just turn the key forward for 11 minutes and off for 30 seconds and do that for a specific number of cycles and it would program it.

 

the vehicle probably will not start...not sure which immobilizer system this year uses; does your key have a + or pk3 on the blade?

 

Do you mean it wont start trying to program the used ECM myself using the method I mentioned in the OP or it won't start period, meaning I can't use a used ECM at all despite factory/dealership reprogramming?

The dealership told me there was a possibility that my model Silverado could be VIN locked, and that one and only one VIN will be compatible with it, but they weren't sure that the 05 had that sort of ECM.

I do not have my keys as of right now so I don't know if it has a '+' or a 'pk3', they are with my mechanic, I'm having the vehicle towed to Reliable Chevrolet here in Springfield MO and I will have to get them then.

 

you can swap the ecm but programming will be required to be able to start the vehicle after the swap.
i think you can program a new vin into the used module.

no matter, its in the dealership hands now anyway.

 

Thanks for your help.

The guy charged me $80 just to diagnose the computer. Oh well, at least I know my problem.