Where is the ecm located on 1991 Chevy Cavalier?
Behind the glove compartment.
Where is the ECM located on a 1991 Chevy Cavalier and would that be the reason for it turning over but not starting?
You can take your vehicle to any Autozone and they will hook it up to the computer and tell you what your ECM has for an error code. IF the ECM or PCM on the vehicle has the problem replaced. The ECM or PCM needs to be reset. Once reset and if the light comes back on, you did not replace the correct part.