ECM challenge

[James Landi]

Has anyone had success substituting a used (reclaimed) ECM in a late model  Cadillac.  The one in our 2006 SRX is partially dead, and GM has a new one and quoted me $1,200 to install and program with NO guarantee that the new one won't be blown out by some existing electronic/electrical issue. I researched the internet, and there are "companies" have them for a fraction of the price, but have lots of disappointed customers. A couple of tech folks tell me that even though the car is running well, it may die at any moment.  I had it diagnosed, and the ECM won't connect with the "analyzer."  We lost traction control, gas and temperature gauge, ignition key removal, and rear lift gate access, and some of the driver information monitors. I tried "recycling" the ecm fuse with the ignition on-- didn't do anything.  My ability to work on cars ENDS with a dwell and multimeter.  Thanks for any information or encouragement .   James

[TJ Hopland]

I don't know.   I think the newer you get the more specific the configuring and programming gets.  I think they have to be told what specific models each module is so different options and car models come into play.   Once it knows what those modules are its also got to be told how to run them.     I think also the newer you get the more serial number specific those modules get so not only do you have to say its a XYX left door module its SN 123.    Maybe for an 06 there are non dealer types out there that can program that stuff but I don't know that for sure. 

You have double and triple inspected and cleaned EVERY ground? I have heard of things like a ground back by the tail lights causing engine running issues on modern cars.   Something about noise in from the fuel pump.   Inspected as much of the harnesses as you can reasonably see?

[klinebau]

A lot of weird stuff can happen on newer vehicles if there are bad or missing grounds.  I would check all grounds to make sure they are clean and tight.  Often the ECU gets blamed after other troubleshooting options are exhausted.  Although there are exceptions, my experience is that either the entire ECU works or it doesn't.  I don't often see partial failures.

[James Landi]

Thank you for your thoughtful responses.  I will check out your ideas--- they sound reasonable, especially considering the fact that 90 percent of the car is operational.   Gratefully,   James