I recently got my ECU changed although it was not causing any symptoms. I was still able to use my car with my original ECU. After getting my ECU changed, my original ECU does not seem to work anymore. I have suspicions that the faulty ECU that was returned to me was not my original car ECU. Is there any way to check using the bar code on the ECU?
It really depends on your year/model but it does not surprise me if your original was sent back non functioning. In many cases the syncing information changes when you replace the pcm. Usually this is simply because of the immobilizer system. However there are ways to clone them so they both would work but the methods vary and you have not supplied enough information.
You will not be able to tell if its your original ecu by any bar code but You could read the VIN using a scan tool. Likely if they sent a different ecu it will contain a different VIN then your own.