I know theres a section for PCM mods but nobody has posted there in years. Hoping by putting this hear maybe someone had the same issue and has a fix.

Just before Thanksgiving I took my 2005 Hummer H2 into a very reputable shop for some repairs, mods, and a full dyno tune.

Engine is a 6.0 with headers/full exhaust, Trailerblazer SS intake and 90mm TB.



The maintenance and mods were completed in a day and then the trouble started.

I had previously obtained a tune based on some mods from Blackbear Performance. When this shop attempted to connect to my ECM it "died". They thought it was just a bad ECM and got another. They installed it and the same thing happened. When they connected it killed the ECM.

I have talked to several shops as have they. The consensus is that a module is communicating at the same time which will kill the ECM. They have disabled everything they can and the problem persists. Onstar, Stereo, something about the transfer case module was suggested, etc. etc.



If anyone has experienced something like this and has input I would greatly appreciate it.

 

 

I actually did the same time as here and got some feedback.

 

Yeah that is usually some aftermarket device being a bit to "chatty" on the communication lines. Radio interfaces and steering wheel control interfaces are the most common culprits but alarms and remote starts can also cause this. Seems that some are more prone to it than others. I have an aftermarket stereo and used the Metra interface for the stereo and the steering wheel controls and it does not bother my EFI Live, and Intune, Tech II, or a generic ELM 327 reader I have.