Hi,
My 2003 CTS was diagnosed with a bad PCM/ECM however the dealer is having a hard time finding one. I did find a used one, but I don't know if it can be self-installed. Could someone please let me know the exact location and how to remove/replace.

Thanks,
DJ

The ECM on a 3.2L motor is mounted on a bracket right above the passenger side valve cover. Easy to get to, but they are VIN encoded like most of the other computers on the car, and you'll need your dealer to replace it so he can clear the VIN and relearn it before the engine will start. The factory shop manual dedicates 437 pages just to the ECM and engine controls!