PO601 CODE does it need a PCM/ecm

[greenman2007]

my 2001 SEBRING CONVERTIBLE failed NJ inspection for the code PO 601...
took the car to autozone and the printout said Defintion: ECM internal fault, Explanation unable to communicate on the SPI line...
Probable cause: 1) shorted input sensor 2). shorted electrical circuit.. 3) failed ECM.

I guess one question would be is the PCM and the ECM the same thing... Its the computer..
Secondly , should I get another one ECM and where can a person buy one where it doesn't cost a arm and a leg...
Does anybody have any suggestions because I need to get my car fixed to get it reinspected...
Is there any sites that have information on this problem and replacement of bad part...
Thanks..