[2006 Chevrolet Uplander, ECM/Inputs/Outputs Waveform]

I can't communicate with PCM when the module is warm but I have communication when is cold (I put the module in fridge). The pattern of class 2 is ok only if i take off all the modules from the network (except PCM). When I put one or more modules the pattern goes bad like you can see in the picture. It's possible that the PCM have a good class 2 pattern alone and a bad pattern with the others modules (I mean the PCM put down the network) ? Sorry for my english.

Florin Nistor
Technician
Continental
Montreal, Quebec, Canada

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